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WGSG Abstracts Volume 27th – 29th June 2018

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Welcome You are very welcome to the fourth meeting of the WGSG (Working Group on Sediment Generation)

in Trinity College Dublin, Ireland. The talks, poster sessions and refreshments will take place within

the Museum Building, which was inspired by the Byzantine architecture of Venice and has housed

the Trinity Geology Department ever since it was constructed in 1857. This WGSG meeting promises

to be very exciting with 75 registered participants, six keynotes talks and a short course on

"Quantifying Sediment Budgets" which takes place the day before the meeting on the afternoon of

Tuesday 26th June.

The scientific committee is delighted to host the fourth WGSG meeting in such a great location and

thank the organizing committee for all their hard work to date. The exciting programme develops on

themes explored at the three previous meetings, and we are sure it will stimulate scientific debate

on the controlling factors and processes regulating sediment generation and their applications to the

sedimentary record.

We are very grateful to Nexen, Providence Resources, Tullow Oil, the Geological Survey of Ireland

and the Irish Centre for Research in Applied Geosciences (iCRAG) for sponsoring the meeting, to the

IAS for providing student travel grants and to our keynote speakers and short course organizers. We

trust you will find the meeting stimulating and enjoyable, and warmly welcome you to Dublin.

David Chew (on behalf of the local organizers),

Luca Caracciolo (WGSG Scientific Committee)

WGSG Scientific committee

Sergio Andò (University of Milano‐Bicocca, IT)

Alessandro Amorosi (Universit y of Bologna, IT)

José Arribas (Universidad Complutense Madrid, ES)

Heinrich Bahlburg (University of Münster, GE)

Sebastien Bertrand (University of Ghent, BE)

Luca Caracciolo (FAU Erlangen‐Nürnberg, GE)

Salvatore Critelli (University of Calabria, IT)

Eduardo Garzanti (University of Milano‐Bicocca, IT)

Matthias Hinderer (TU Darmstadt, GE)

Laura Stutenbecker (TU Darmstadt, GE)

Pieter Vermeesch (University College London, UK)

Hilmar von Eynatten (University of Göttingen, GE)

Gert Jan Weltje (University of Leuven, BE)

Local organizing committee

David Chew, Chris Mark, Gary O’Sullivan (Trinity College Dublin)

Shane Tyrrell (National University of Ireland Galway)

Peter Haughton (University College Dublin)


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SHORT COURSE

Quantifying sediment budgets from source to sink – with emphasis on evaluating the effects of disturbances

26th June 2018 (1‐5pm), Trinity College Dublin

Amy East and Jonathan Warrick

U.S. Geological Survey, Pacific Coastal and Marine Science Center, Santa Cruz, CA

Purpose and scope:

Tracking the movement of sediment from source areas through transport zones to

depositional sinks is a problem central to many modern and ancient sedimentological

investigations. One particular long‐standing problem in sedimentology and earth‐surface

process studies has been that of landscape response to substantial changes in sediment

supply. Such sediment‐supply changes can occur in response to natural or anthropogenic

landscape disturbances, including landslides, emplacement or removal of dams on rivers,

volcanic eruptions, mining activity, deforestation, and urbanization; the effects of such

disturbances are most readily measured through the use of quantitative sediment budgets.

This half‐day short course in sediment budgeting concepts, uses, and methodology would

synthesize theory and practical applications of using source‐to‐sink sediment budgets in a

variety of landscape contexts, drawing on modern and ancient examples. Applications

would focus primarily on modern, fluvial settings, incorporating practical exercises to

quantify sediment movement, predict downstream response to new sediment generation,

and address best practices and uncertainty in using sediment‐transport measurements and

digital elevation models (DEMs) to calculate sediment budgets.


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Course outline:

Introduction and overview (1 hour, including discussion time):

Utility of sediment budgeting in modern and ancient sedimentology studies

Basic theory and practices in quantifying sediment budgets for modern systems

Indeterminacy problems and their relevance to sediment management

Break (10–15 min)

Module 1 (1 hour): Sediment transport from source to sink in a modern fluvial system

Focus on point‐source sediment production, using as an example the problem of dam

removal and associated fluvial sedimentary response. Emphasize both research value and

management applications. Topic is relevant especially for scientists working in Europe and

U.S., as the age of many dams in those regions relative to their expected lifespan has meant

the practice of removing obsolete dams is becoming increasingly common.

Exercise (in breakout groups if numbers warrant): Predict/estimate downstream effects of

sediment release from a point source such as a dam removal, including bed aggradation,

transport time for sediment slug to advance a given distance downstream, and longevity in

the coastal or fluvial‐confluence depocenter. Develop work plan to predict and assess the

magnitude and duration of effects.

Break (10–15 min)

Module 2 (1–1.5 hours): Remote‐sensing applications for sediment budgeting

Recent advances in DEM generation, especially the use of cost‐effective Structure‐from‐

Motion photogrammetry, and applications to quantifying sediment budgets

Estimating and minimizing uncertainty in DEM differencing

Exercise (in breakout groups if numbers permit): Manipulate digital landscape surfaces

produced from Structure from Motion photogrammetry in order to calculate sediment

erosion and deposition volumes

Requirements: Laptop (PC or Mac both would work), Agisoft Photoscan software (30‐day free trial),

Cloud Compare software (free, open source).


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Programme Wednesday 27th June Lecture Theatre, Museum Building 09.00 – 11.00 Registration

Entrance Hall, Ground Floor, Museum Building

11.00 ‐ 11.30 Coffee (Registration continues)

11.30 – 11.40 Welcome Address 11.40 – 12.15 Introduction to the Working Group on Sediment Generation.

Theme 1: Sediment Generation and Transport 12.15 – 13.00 Keynote Talk: Seismic and meteorological drivers of sediment production

Niels Hovius

13.00 ‐ 14.00 Lunch

14.00 – 14.45 Keynote Talk:

Scratching the surface of Antarctic landscape evolution with cosmogenic nuclides and a drill Gordon Bromley, Alexandra Balter, Greg Balco & Margaret Jackson

14.45 – 15.00 The Orange littoral sand highway: 1. Ultralong multistep fluvial‐marine‐

eolian transport poses a further thorny challenge to provenance research Eduardo Garzanti, Pedro Dinis, Pieter Vermeesch, Sergio Andò, Mara Limonta, Alberto Resentini & Giovanni Vezzoli

15.00 – 15.15 The Orange littoral sand highway: 2. An unexcelled natural laboratory in

which to quantify mechanical abrasion and mineral durabilities during ultralong sediment transport Alberto Resentini, Sergio Andò, Eduardo Garzanti

15.15 – 15.35 Creating a desert: sediment generation patterns and relentless aeolian activity in the Namib Sand Sea (Namibia) over the last 11 Ma. Caracciolo, L., Stollhofen, H., Garzanti, E., Limonta, M., Troidl, A., Hatzenbühler, D.,

Vermeesch, P.


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15.35 ‐ 16.10 Coffee

16.10 – 16.30 Po Plain‐Northern Adriatic Foreland basin source‐to‐sink sediment system during Plio‐Pleistocene time: Evaluating tectonics vs. climate as erosion drivers Chiara Amadori, Andrea Di Giulio, Giovanni Toscani

16.30 – 16.50 Catchment changes in response to tectonics and climate: using river

terraces and DEM data in the southern High Atlas Mountains (Morocco) Jesse R. Zondervan, Martin Stokes, Sarah J. Boulton, Anne E. Mather, Matthew W. Telfer

16.50 – 17.10 Numerical modelling of sediment generation: characterisation of granitoid parent rocks Bram Paredis & Gert Jan Weltje

17.10 – 17.50 Wrap up and mini‐break‐out session

18.00 ‐ 20.00 Ice breaker and poster session

Entrance Hall, Ground Floor, Museum Building and

Lecture Theatres A & B, Ground Floor, Museum Building


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Thursday 28th June Lecture Theatre, Museum Building Theme 2: Sedimentological studies 09.00 – 09.20 Timing of lacustrine expansion, sediment deposition and carbon

drawdown during the early Toarcian Oceanic Anoxic Event (~183 Ma) Ruhl, M., Xu, W., Hesselbo, S.P., & Jenkyns, H.C.

09.20 – 09.40 A new theoretical framework for the transfer of periodic environmental

signals to the stratigraphic record. Stephan Toby, Rob Duller, Silvio De Angelis, Kyle Straub

09.40 – 10.00 Porosity of uniform sands and gravels as a function of packing state and

particle properties (size, roundness and sphericity) Gert Jan Weltje


Grave to Cradle: Accounting for Sediment Genetics in Hydrocarbon Exploration Bill Heins

10.45 – 11.00 Wrap up of morning session

11.00 ‐ 11.30 Coffee

Theme 3: Big data and automated data collection 11.30 – 11.50 High‐resolution reservoir quality prediction from cores by multifaceted

analysis: a Carboniferous example from the Dutch offshore Saturnina Henares, Menno R. Bloemsma, Marinus E. Donselaar & Gert Jan Weltje

11.50 – 12.10 Using “virtual microscopy” to re‐imagine and revitalize petrographic analyses Suzanne Kairo and Christopher M. Prince

12.10 – 12.30 High resolution heavy mineral analysis by automated Raman spectroscopy N. Keno Lünsdorf, Jannik Kalies, Patrick Ahlers, István Dunkl & Hilmar von Eynatten

12.30 – 12.50 Automated data collection and analysis, current capability and future potential: Example of a 1000 sample QEMSCAN dataset. Jenny Omma

12.50 – 13.00 Wrap up of late morning session


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13.00 ‐ 14.00 Lunch

14.00 – 14.45 Keynote Talk: Decoding transient tectono‐climatic signals from the sedimentary record

Alexander C. Whittaker

Theme 4: New Approaches to Sedimentary Provenance 14.45 – 15.05 Testing the utility of apatite fluorine and chlorine content in sediment

source tracking Claire Ansberque, Chris Mark, John Caulfield and David Chew

15.05 – 15.25 Effective mineral quantification for arkosic sandstones using SEM imaging and element mapping ahead of common Pb isotopic analysis Sebastian Zimmermann, Peter Haughton, Shane Tyrrell

15.25 ‐ 16.00 Coffee

16.00 – 16.20 Babel or Esperanto? The need of finding a common language in heavy

mineral analyses István Dunkl, Hilmar von Eynatten, Keno Lünsdorf, Sergio Andò & Andrew C. Morton

16.20 – 16.40 A workflow for analysis of compositional data in sedimentary petrology: inferring provenance changes in sedimentary basins from spatio‐temporal variation in heavy‐mineral assemblages Jasper Verhaegen & Gert Jan Weltje

16.40 – 17.00 How to average point‐counting data

Pieter Vermeesch

17.00– 17.50 Wrap up and mini‐break‐out session 18.00– 19.00 Poster session

Lecture Theatres A & B, Ground Floor, Museum Building

19.30 ‐ late Conference Dinner

Ely Bar & Grill, IFSC, Dublin 1


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Friday 29th June Lecture Theatre, Museum Building Theme 4: New Approaches to Sedimentary Provenance (continued) 09.00 – 09.20 Sedimentary provenance analysis meets ultrahigh‐pressure research

Jan Schönig, Guido Meinhold, Hilmar von Eynatten & Nils K. Lünsdorf

09.20 – 09.40 Hydrated‐heavy‐mineral signature in orogenic sediments

(Indus Fan, IODP Exp. 355) Sergio Andò, Wendong Liang, Mara Limonta, Chiara Ileana Paleari, Alberto Resentini & Eduardo Garzanti

Theme 5: Case Studies in Sedimentary Provenance 09.40 – 10.00 Possibilities and limitations of multi‐proxy detrital thermochronology: The

Bengal and Indus Fans as archives of Himalayan exhumation Chris Mark, Yani Najman, Peter Clift, Andrew Carter, Dan Barfod, David Chew, Daniel Döpke & Randall Parrish


The initiation and evolution of the Irrawaddy drainage, with implications for the palaeo‐drainage and crustal evolution of eastern Asia. Peng Zhang, Yani Najman, Lianfu Mei, Ian Millar, Edward Sobel, Dan Barfod, Xiaolin Hu

10.45 – 11.00 Wrap up of morning session

11.00 ‐ 11.30 Coffee


A Neogene record of Himalayan erosion: the IODP Expedition 354 transect in the Bengal fan at 8° N Christian France‐Lanord, Volkhard Spiess, Sébastien Lenard, Albert Galy, & Jérôme Lavé

12.15 – 12.35 Precisely constraining the timing of the India‐Asia continental collision by provenance change Xiumian Hu, Wei An , Eduardo Garzanti & Jiangang Wang

12.35 – 12.55 Mixing it up: Source switching in the Late Jurassic‐Early Cretaceous Scotian Basin, offshore Nova Scotia revealed by multi‐proxy provenance analysis Aoife Blowick, Georgia Pe‐Piper, David Piper & Shane Tyrrell


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12.55 – 13.15 The initiation and evolution of the river Nile Laura Fielding, Yani Najman, Ian Millar, Peter Butterworth, Eduardo Garzanti, Giovanni Vezzoli, Dan Barfod & Ben Kneller

13.15 – 13.30 Wrap up of late morning session

13.30 ‐ 14.30 Lunch

14.30 – 16.30 Breakout sessions 16.30 – 17.00 Wrap up talk and close of meeting


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Listing of Poster Presentations (In alphabetical order by first author)

Provenance of Carboniferous Deltas – Point sources and Mixed Signals.

Bébhinn Anders, Shane Tyrrell, John Murray & John R. Graham

Quartz and zircon de‐coupling in sandstone: petrology and quartz cathodoluminescence of the German Triassic Buntsandstein Group

Carita Augustsson, Michaela Aehnelt, Thomas Voigt, Cindy Kunkel, Marcus Meyer & Florian Schellhorn

Pb isotopic fingerprinting of plagioclase as a sand tracking tool: A validation study

Aoife Blowick, Shane Tyrrell & Peter Haughton

Provenance of Permian‐Triassic metasedimentary rocks in the Antarctic Peninsula and southern Patagonia using U‐Pb age, Lu‐Hf and O isotopic compositions in zircon

Paula Castillo & Mark Fanning

Examples of provenance studies in tsunami deposits

Pedro J. M. Costa

The interplay of sandstone petrofacies and porosity and permeability: implications for reliable quality prediction in clastic turbiditic wedges of the southern Apennines foreland region, Italy

Salvatore Critelli, Mario Borrelli, Gloria Campilongo, Francesco Muto, Enza Nicoletti, Edoardo Perri, Francesco Perri & Vincenzo Tripodi

A suggested standard schema for use in organising and reporting sediment provenance datasets

Lorin Davies, Sam Fielding, Ian Millar & Laura Fielding

Detrital record of the denudation of volcanic islands in sub‐tropical climate

Pedro A. Dinis & Marina C. Pinto

A sedimentary provenance study of modern river sands from northern Fennoscandia and its insight on identifying mineral fertility, bias and the source of Mesozoic successions deposited on the Barents Shelf

Michael J. Flowerdew, Edward J. Fleming, David M. Chew, Andrew C. Morton, Magdalena Biszczuk, Dirk Frei & J. Stephen Daly


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Sand composition as a tool for liquefaction phenomena assessment

Daniela Fontana & Stefano Lugli

Mineralogy and Genesis of Manganese Ores of Tunisia: Preliminary Results

Hechmi Garnit , Donatella Barca, Salah Bouhlel & Mariano Davoli

One small terrane‐boundary basin – five different sources of sediment

Peter Haughton

Provenance and tectonic setting of the Slovenj Gradec Basin sedimentary succession (Western part of the Pannonian Basin system)

Kristina Ivančič, Mirka Trajanova, Dragomir Skaberne & Andrej Šmuc

Sediments of two Gondwana glaciations in Ethiopia: Provenance information from heavy minerals and detrital zircon ages

Anna Lewin, Guido Meinhold, Matthias Hinderer, Enkurie L. Dawit & Robert Bussert

An Empirical Method to Predict Sediment Grain Size from Inorganic Geochemical Measurements

Dawei Liu, Sebastien Bertrand & Gert Jan Weltje

Spatial and temporal variation in fluvial sediment supply to the Cretaceous Western Interior Seaway of North America

Sinéad Lyster, Alexander Whittaker, Peter Allison & Sarah‐Jane Kelland

Sediment hunting: Provenance of the Upper Jurassic NCSB and what we know

Odhran McCarthy, Pat Meere & Dave Chew

The lithostratigraphy of the Bradfield Southend Boreholes, Berkshire UK: An examination of the Late Cretaceous – Palaeogene boundary in the western London Basin.

Ian Mounteney, Peter Hopson, Seb Gurrola, Rosemary Jenkins, Ian Wilkinson, Mark Woods & Steve Thorpe

Geochemical evidence for large‐scale drainage reorganization in Northwest Africa during the Cretaceous

Yannick Mourlot, Martin Roddaz, Guillaume Dera, Gérôme Calvès, Jung‐Hyun Kim, Anne‐Claire Chaboureau, Stéphanie Mounic & François Raisson

Sedimentary provenance studies in Brazil

Daniel Rodrigues do Nascimento Jr. and Pâmella Moura


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Heavy mineral variations in deltaic sandstones: towards a better understanding of pre‐depositional sediment history?

Martin Nauton‐Fourteu, Shane Tyrrell & Andrew C. Morton

Provenance and facies analysis evolution of extensional basins: a case study of the Permotriassic Mitu Group (Central Andes, Peru)

Fernando Panca, Heinrich Bahlburg & Jasper Berndt

Advanced proxies for provenance, erosion and transport mechanisms of modern stream sediments – An application of SEM‐based quantitative mineralogical analysis

Sophia Rütters, Raimon Tolosana Delgado & Jens Gutzmer

Detection of polymorphous alumosilicates by Correlative Raman Imaging and Scanning Electron Microscopy (Raman‐SEM)

Maria Sitnikova, Irene Bitz & Reiner Dohrmann

A database for compositional data

Laura Stutenbecker, Adrian Linsel, Luca Caracciolo, Pieter Vermeesch & Matthias Hinderer

Provenance of sands from the SE North Sea: Scandinavian vs. Central European signals

Hilmar von Eynatten, Philipp Führing, Marius Aschoff, Eric Seest & István Dunkl


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Theme 1

Sediment Generation and Transport


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KEYNOTE Seismic and meteorological drivers of sediment production

Niels Hovius

GFZ German Research Centre for Geosciences, Telegrafenberg, Potsdam, Germany

A combination of regular hydrometric and novel geophysical monitoring and remote sensing of

atmospheric and surface observables is now allowing a close look at how tectonic and climatic

conditions set the sediment supply to basins at the scale of events. These approaches reveal

predictable, first‐order links between external drivers and erosional response, but also time‐ and

history‐dependent behaviour after large perturbations, tipping points across which small changes

have major consequences, and overwhelming impacts of unusual events.

In this presentation, I shall aim to demonstrate how simple, physically based models can be used to

anticipate the sediment production due to an earthquake or rainstorm. For example, in steep

terrain, earthquakes cause landsliding in proportion to their mechanism, moment magnitude and

source depth, and to the steepness of the excited topography. Earthquakes also cause damage in

shallow substrates, which changes the propensity to slope failure induced by other triggers.

Subsequent healing gives rise to a transient pulse of sediment production by mass wasting after

earthquakes, which eschews normal relations between rainfall and sediment production. The

routing of sediment generated during such episodes remains poorly constrained, and blends into

the long‐term flux of sediment from uplands. In the epicentral area of the 2015 Gorkha

earthquake, this long‐term flux has a further term, which is not directly related to seismic and

meteorological drivers. Glacier lake outburst floods have a special ability to move very large and

normally stable boulders in the riverbed, unlocking sediment in the valley floor and debuttressing

adjacent hillslopes. The impact of such floods may dominate sediment production on decadal to

centennial time scales, by a mechanism that is linked with climate and climate change in a less

conventional way. Vegetation is another factor that modulates the effects of climatic drivers on

sediment sourcing. In Upper Mustang, current sediment production rates, prorated for rainfall

forcing, are two orders of magnitude higher than in the high Himalayas, immediately to the south.

This may be a relatively recent phenomenon, resulting from a geomorphic tipping point following

aridification and the demise of the contiguous vegetation cover of this sensitive high altitude

environment. These examples serve to show that sediment production and routing are part of a

process cascade in response to tectonic and climatic impacts on the Earth’s surface, articulated

through process links across a range of spatial and temporal scales.


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KEYNOTE Scratching the surface of Antarctic landscape evolution with cosmogenic

nuclides and a drill

Gordon Bromley1,2*, Alexandra Balter2, Greg Balco3, Margaret Jackson4

*[email protected]

1Geography, NUI Galway, Galway

2Climate Change Institute, University of Maine, Orono, Maine, USA

3Berkeley Geochronology Center, 2455 Ridge Road, Berkeley, California, USA

4Earth Sciences Department, Dartmouth College, Hanover, New Hampshire, USA

With 98% of the continent buried by ice, our geologic view of Antarctica is highly restricted relative

to the other six continents. Nonetheless, thanks to the persistence of cold, hyper‐arid climate

conditions, what land is exposed constitutes a vast laboratory for investigating such processes as

uplift and erosion, sediment production and dispersal, volcanism, ice sheet stability (and thus the

Antarctic contribution to eustatic sea level), and long‐term climate variability. Looking farther

afield, Antarctica is also a key source of extra‐terrestrial information as well as a Martian analogue.

Coupled with the refinement of cosmogenic nuclide techniques over the last two decades, this

unique degree of landscape preservation means we can now start putting numbers to persistent

questions in Antarctic science, and from there explore implications for Earth’s history more

broadly.

Since 2015, we have been conducting a glacial‐geologic investigation in the southern Transantarctic

Mountains (TAM) that, first and foremost, seeks to establish the sensitivity of the vast East

Antarctic Ice Sheet (with ~50 m sea‐level equivalent) to warmer‐than‐present climate conditions.

Focusing on the Pliocene and Miocene periods, when Earth’s climate is thought to have been

warmer than today – and arguably analogous to our greenhouse future – we have applied

cosmogenic 3He, 21Ne, and 10Be to date changes in ice sheet thickness at two remote field sites at

85°S: Roberts Massif and Otway Massif. The results of that work, which is nearing its conclusion,

are tantalising and this talk will cover both the new geologic record for Earth’s largest ice sheet and

its implications for past and future sea level.

There is more to this cosmogenic data set, however, than a simple story of Antarctic ice volume and

so this talk will explore some of the more nuanced outcomes of the investigation. For one, a

multiple‐nuclide approach has enabled us to constrain surface erosion rates in the TAM and also

place limits on mountain uplift, both of which have been a source of almost comical contention for

decades. Secondly, we have extended the boundaries of the noble gas measurements on terrestrial

surfaces and, in so doing, shed new light on long‐term climate variability on the Antarctic continent.

Thirdly, and perhaps most crucial of all, we have identified fundamental gaps in our understanding

of cosmogenic nuclide production rates and the ‘scaling schemes’ we rely on to apply the method

anywhere on Earth.


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The Orange littoral sand highway: 1. Ultralong multistep fluvial-marine-eolian transport poses a further thorny challenge to provenance research

Eduardo Garzanti*1, Pedro Dinis2, Pieter Vermeesch3, Sergio Andò1, Mara Limonta1, Alberto

Resentini1, Giovanni Vezzoli1

*[email protected]

1 Laboratory for Provenance Studies, Department of Earth and Environmental Sciences, Università di

Milano‐Bicocca, 20126 Milano 2 IMAR‐CMA Centro do Mar e Ambiente, Departamento de Ciências da Terra, Universidade de

Coimbra, Largo Marquês de Pombal, 3000‐272 Coimbra, Portugal 3 London Geochronology Centre, Department of Earth Sciences, University College London, London

WC1E 6BT, UK

Sand carried from Lesotho and Southafrica to the Atlantic Ocean by the Orange River is dragged by

swell waves and persistent southerly winds to accumulate in four successive dunefields in coastal

Namibia to Angola1,2,3. All four dunefields are terminated by river valleys, where eolian sand is

flushed back to the ocean. And yet sediment transport continues at sea, tracing a 1800 km‐long

submarine sand highway. Sand drift would extend northward to beyond the Congo if the shelf did

not become progressively narrower in southern Angola, where drifting sand is funnelled towards

oceanic depths via canyon heads connected to river mouths. More than half of Moçamedes Desert

sand in southern Angola is derived from the Orange River, and the rest in similar proportions from

the Cunene River and the Swakop River draining the Damara orogen in Namibia. The Orange

fingerprint, characterized by basaltic rock fragments, clinopyroxene grains, and bimodal zircon‐age

spectra with peaks at 0.5 and 1.0 Ga, is lost abruptly at Namibe, and beach sands farther north

have abundant feldspar, amphibole‐epidote suites, and unimodal zircon‐age spectra with peak at 2.0 Ga, documenting local provenance from Paleoproterozoic basement. In modern settings, high‐

resolution multimineral studies allow us to trace complex multistep sediment pathways through

different environments over distances of thousands of kilometers. But what are the chances to

unravel such intricacies, reconstruct complex source‐to‐sink relationships, and make correct

sediment budgets in ancient cases?

1. Garzanti, E., Andò, S., Vezzoli, G., Lustrino, M., Boni, M., & Vermeesch, P., Petrology of the Namib sand sea:

long‐distance transport and compositional variability in the wind‐displaced Orange Delta. Earth Sci. Rev., 112,

173‐189 (2012). 2. Garzanti. E., Vermeesch, P., Andò, S., Lustrino, M., Padoan, M., & Vezzoli, G., Ultra‐long

distance littoral transport of Orange sand and provenance of the Skeleton Coast Erg (Namibia). Marine

Geology, 357, 25‐36 (2014). 3. Garzanti, E., Dinis, P., Vermeesch, P., Andò, S., Hahn, A., Huvi, J., Limonta, M.,

Padoan, M., Resentini, A., Rittner, M., & Vezzoli, G., Sedimentary processes controlling ultralong cells of littoral

transport : placer formation and termination of the Orange sand highway in southern Angola, Sedimentology,

65, 431‐460 (2018).


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The Orange littoral sand highway: 2. An unexcelled natural laboratory in which to quantify mechanical abrasion and mineral durabilities during

ultralong sediment transport

Alberto Resentini*, Sergio Andò, Eduardo Garzanti

*[email protected]

Laboratory for Provenance Studies, Department of Earth and Environmental Sciences, Università di

Milano‐Bicocca, 20126 Milano

A mathematical method based on image analysis allowed us to measure the textural properties of

heavy minerals in fluvial, aeolian‐dune and beach sediments throughout the 1800 km‐long Orange

cell of littoral sand transport, the longest documented so far on our planet. We analysed the grain

size and shape of 12,700, grains including all major heavy‐mineral species contained in 22 selected

samples collected along the Atlantic coast, from Namibia to southern Angola1,2. In this unique

natural laboratory, where the Orange River represents a single dominant sediment source

characterized by diagnostic compositional fingerprints, hyperarid climate ensures limited chemical

alteration of even unstable ferromagnesian minerals.

This case study led us to: a) monitor changes in grain size and roundness of different detrital

minerals during ultralong transport in high‐energy shallow‐marine and aeolian environments; b)

determine the relative durability of different detrital minerals to mechanical wear as a function of

their mineralogical properties (e.g., hardness, cleavability); c) compare roundness of grains in sands

of different facies to establish the relative efficiency of mechanical processes as a function of

depositional environment and transporting medium (i.e., water versus air); d) compare roundness of

the same detrital species in beach deposits enriched in heavy minerals to different degrees and

evaluate whether rounded grains are preferentially entrained or left behind during high‐energy

storm events; e) test the use of textural properties to distinguish between coarser or angular grains

of local provenance from smaller or rounded grains derived from distant sources. The rigorous

definition of particle shape and the measurement of grain roundness is a necessary step to achieve a

full understanding of sedimentary processes, evaluate mechanical effects during long‐distance

transport, challenge untested assumptions, and obtain useful complementary information on

sediment provenance.

1. Garzanti, E., Resentini, A., Andò, S., Vezzoli, G., & Vermeesch, P., Physical controls on sand composition and

relative durability of detrital minerals during long‐distance littoral and eolian transport (coastal Namibia).

Sedimentology, 62, 971‐996 (2015). 2. Resentini, A., Andò, S., & Garzanti, E., Quantifying roundness of detrital

minerals by image analysis: sediment transport, shape effects, and provenance implications. Journal of

Sedimentary Research, 88, 276–289 (2018).


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Creating a desert: sediment generation patterns and relentless aeolian activity in the Namib Sand Sea (Namibia) over the last 11 Ma.

Caracciolo, L.1, Stollhofen, H.1, Garzanti, E.2, Limonta, M.2, Troidl, A.1, Hatzenbühler, D.1, Vermeesch,

P.3

1Friedrich‐Alexander Erlangen University (FAU) Erlangen‐Nuremberg, GeoZentrum Nordbayern,

Schlossgarten 5, 91054, Erlangen, Germany 2Laboratory for Provenance Studies, Department of Earth and Environmental Sciences,Università di

Milano‐Bicocca, 20126 Milano, Italy 3University College London, London WC1E 6BT, UK

The Namib Sand Sea hosts among the highest sand dunes and is one of the most extreme

environments on the planet. The permanent arid conditions, lasting since at least 55 Ma, make the

Namib perhaps the oldest desert on Earth. The origin and composition of excessive sand volumes

results from long‐distance northward littoral transport from the Orange River mouth, fuelled by

swell waves generated at high southern latitudes. The interplay of such powerful processes controls

sediment transfer and fractionation, with part of the sandy detritus being blown inland and stored in

the sand sea whereas the rest is transported as far north as the Moçadames desert in Southern

Angola (Garzanti et al. 2017). Sand dunes of the Namib Desert are only moderately quartzose, and

include diverse unstable mineralogical components, which is rather unusual for large deserts such

as the Sahara, characterized by pure quartzose sand. Modern sediments of the Namib desert are

feldspatho‐litho‐quartzose to litho‐feldspatho‐quartzose including abundant mafic

volcanic/subvolcanic and sedimentary (shale/sandstone, carbonate) rock fragments and rich heavy‐

mineral assemblages dominated by clinopyroxene, associated with opaque Fe–Ti–Cr oxides, epidote,

amphibole and garnet (Garzanti et al., 2014 and references therein). The comprehensive provenance

dataset available from the literature indicates that Skeleton Coast dune sand is derived mostly from

the Orange River and ca 20% from metamorphic and granitoid rocks of the Damara Orogen through

the Swakop River (Garzanti et al. 2014 and references therein).

This study (in progress) focuses on the inland part of the Namib desert, where the aeolian

sandstones of the late Miocene to mid Pliocene Tsondab Formation represent fossil equivalents of

the present day dune system. The research also includes compositionally ground‐truth remote‐

sensing mineralogy, the aim of which is to understand the ephemeral river – dune interaction in the

present day setting and to transfer the acquired knowledge to older sediments. Study areas include

the Soussvlei, where the Tsauchab River dies within the dunes to form playa‐lake systems.

Sandstone petrography, heavy‐mineral analysis, bulk‐rock geochemistry and stable isotopes are used

to: (i) determine the composition of the late Miocene to mid Pliocene Tsondab Sandstone; (ii)

compare it to those of modern sands; (iii) constrain the sediment routing system throughout the

Neogene; and, (iv) discuss the preliminary results in relationship with climatic regimes. Diagenetic

processes are also investigated, focusing on the influence of sediment composition on early

consolidation mechanisms. The characterisation of lithification processes on recent and older dunes

provides elements allowing us to reconstruct the fate of sand grains transported by the Orange

River, blown inland into the Namib desert, and lithified through the formation of clay coatings and

early carbonate cementation.

1.Garzanti, E., Vermeesch, P., Andó, S., Lustrino, M., Padoan, M., Vezzoli, G., Ultra‐long distance littoral

transport of Orange sand and provenance of the Skeleton Coast Erg (Namibia). Marine Geology. 357, (2018).


20

Po Plain-Northern Adriatic Foreland basin source-to-sink sediment system during Plio-Pleistocene time: Evaluating tectonics vs. climate as erosion

drivers

Chiara Amadori1*, Andrea Di Giulio1, Giovanni Toscani1

*[email protected]

1University of Pavia, Department of Earth and Environmental Sciences, Via Ferrata 1, 27100 Pavia,

Italy.

Worldwide data from tectonically active and inactive mountain regions record an increase of

sediment input to sedimentary basins during the last million years, concomitantly with the cooling of

global climate1. This, pushed some authors to conclude that Pliocene‐Pleistocene climate (i.e.

affected by high amplitude oscillating conditions) has been more efficient than tectonics in triggering

mountain erosion2. To estimate the relative efficiency of tectonics with respect to climate in eroding

mountain belts, a closed and highly constrained system is needed. The Po Plain‐Northern Adriatic

Foreland System (PPAF), provides an ideal case of study to test this hypothesis.

During Plio‐Pleistocene time the foredeep setting was relatively confined (i.e. without significant

sediment escape) because largely surrounded by collisional belts (Alps, Northern Apennines and

Dinarides) providing a fairly high siliciclastic input and producing a quite continued sedimentary

record.

This work presents a detailed basin‐scale 3D model of the PPAF infilling derived from the

interpretation of a dense seismic network integrated with more than 100 well logs (dataset provided

by ENI). The resulting 3D subsurfaces architecture is made of 6 chronologically constrained regional

unconformities3 referred as: base Pliocene, intra‐Zanclean, intra‐Piacenzian, intra‐Gelasian, base

Calabrian and late Calabrian. The 3D block was depth‐converted using a 3D‐velocity model and

decompacted to avoid compaction‐related bias. The 3D modelling enables to investigate step‐by‐

step the basin geometry and quantify the sediment input through space and time (i.e. sediment

flux).

The obtained fluxes show a two‐folds increase occurred since 2.58 Ma (~21,000 km3/Ma) with

respect to Pliocene time (~10,000 km3/Ma).

More in detail, during Gelasian time, the Northern Apennines experienced the last strong tectonic

phase that is recorded in the basin by an increase in sediment flux from ~8,500 km3/Ma during

Piacentian, to ~13,000 km3/Ma. After that, since Calabrian, both Alpine and Apennine belts

underwent strong decrease in tectonic activity but the sediment flux increased up to ~29,000

km3/Ma, exactly when climate cooling and cyclicity increased the most.

Therefore we argue that a cool, highly oscillating climate, causing glacial‐interglacial cycles is

approximately 2 times more efficient than tectonics in promoting the erosion of mountain belts and

the related detrital input in the surrounding sedimentary basins.

1. Molnar, P., Late Cenozoic increase in accumulation rates of terrestrial sediments: how might climate change have

affected erosion rates? Annual Review of Earth Planetary Science, 32, (2004). 2. Kuhlemann, J., Frisch, W., Székely,

B., Dunkl, I., & Kázmér, M., Post‐collisional sediment budget history of the Alps: tectonic versus climatic control.

Internarional Journal of Earth Sciences, 91, (2002). 3. Ghielmi, M., Minervini, M., Nini C., Rogledi, S., & Rossi, M., Late

Miocene‐Middle Pleistocene sequences in the Po Plain‐Northern Adriatic Sea (Italy): The stratigraphic record of

modification phases affecting a complex foreland basin. Marine and Petroleum Geology, 42, (2013).


21

Catchment changes in response to tectonics and climate: using river terraces and DEM data in the southern High Atlas Mountains (Morocco)

Jesse R. Zondervan1*, Martin Stokes1, Sarah J. Boulton1, Anne E. Mather1, Matthew W. Telfer1

*[email protected] 1School of Geography, Earth and Environmental Sciences, Plymouth University, Plymouth PL4 8AA Tectonics and climate drive the generation and transport of sediment in mountain rivers as these evolve over time. On a glacial‐interglacial scale, in particular catchment reorganisation and catchment incision dynamics control these processes, and affect fan deposition in sedimentary basins1. The Atlas Mountains in Morocco exhibit ongoing catchment reorganisation and an abundance of river terraces recording glacial fluvial aggradation and interglacial‐glacial incisional periods2, opening up insight into the processes behind catchment evolution over geological timescales. Topography and river profiles across drainage divides are similar in a stable divide, and if they are unequal they indicate active catchment reorganisation. When reorganisation occurs, it results in irregularities in river long profiles and changes in river valley erosion. River strath terraces are formed by transition between valley widening and downcutting of terraces in response to local divergence of sediment‐transport capacity3. Consequently, they record changes in catchments due to river capture, climate and tectonics. The presence of river terraces enables catchment processes over time to be investigated. A combination of remote sensing and field mapping and logging was completed in May 2018. River terraces have been mapped with newly released high resolution DEM data in the southern High Atlas in Morocco, and additional surveying was done in the field. Geomorphological indices suggest river catchment capture is a key control on the development of drainage networks. River long profiles suggest tectonic controls have also influenced landscape development over the last few million years4. Logging of terrace sediments together with high‐resolution sampling for OSL dating enables these catchment‐wide effects to be compared with paleo‐hydrological and sediment transport characteristics of the fluvial system. The combination of geomorphological DEM and sedimentological field data enables us to explore drivers of catchment change, and will contribute to the wider understanding of fluvial system response to climate and tectonic controls, and to its transport into the sedimentary record.

1. Mather, A. E., Harvey, A. M., and Stokes, M., 2000, Quantifying long‐term catchment changes of alluvial fan

systems: GSA Bulletin, v. 112, no. 12, p. 1825‐1833. 2. Stokes, M. et al. Controls on dryland mountain

landscape development along the NW Saharan desert margin: Insights from Quaternary river terrace

sequences (Dadès River, south‐central High Atlas, Morocco). Quaternary Science Reviews 166, 363‐379,

doi:10.1016/j.quascirev.2017.04.017 (2017). 3. Hancock;, G. S. & Anderson, R. S. Numerical modeling of fluvial

strath‐terrace formation in response to oscillating climate. GSA Bulletin 114, 1131‐1142, doi:10.1130/0016‐

7606(2002)114<1131:NMOFST>2.0.CO;2 (2002). 4. Boulton, S. J., Stokes, M., and Mather, A. E., 2014, Transient

fluvial incision as an indicator of active faulting and Plio‐Quaternary uplift of the Moroccan High Atlas:

Tectonophysics, v. 633, p. 16‐33.


22

Numerical modelling of sediment generation: characterisation of granitoid parent rocks

Bram Paredis1*, Gert Jan Weltje1

* [email protected]

1Department of Earth and Environmental Sciences, KU Leuven, Celestijnenlaan, Leuven, Belgium

The Sediment Generation model (SedGen) currently under construction is aimed at simulating the chemical and mechanical weathering of crystalline parent rocks to sediments. An obvious starting point for any attempt to model these processes is a comprehensive characterisation of the starting material’s properties, which define the initial conditions of the simulation. Griffiths was the first to recognize that sandy sediments can be fully characterized by a combination of five fundamental properties, namely “(1) the kinds and volumetric proportions of the elements, (2) their size distributions, (3) their spatial arrangement, (4) their shape distributions, and (5) their orientation distributions”1, 2.

We generalized the Griffiths descriptor to encompass common crystalline rocks, so as to turn it into a general petrological tool. In the case of granitoid rocks, the fundamental properties considered are modal mineralogy, crystal‐size distributions, and normalised crystal‐interface frequencies. The latter may be viewed as an extension of property (3), which is equated to packing density in sands, but must be specified for each mineral separately in igneous and metamorphic rocks with non‐random texture. Properties (4) and (5) are not taken into account in our description, as we consider all crystals to be approximately spherical, in order to keep the model tractable and reduce its computational overhead. Granitoid rocks have been selected as test data for SedGen, as they represent the most common type of igneous rock at the Earth's surface and tend to produce large quantities of sand.

We will show examples of the variability of the three fundamental properties in granitoids, and discuss their inter‐relationships. Because sediments generated in first‐order (monolithologic) drainage basins typically offer a mixture of detritus generated in an area of several km2, knowledge of the joint distribution of fundamental properties is of major importance for assessing the goodness of fit of SedGen simulations. Quantification of the joint variability of texture and composition has not been popular in the field of igneous petrology, although considerable attention has been devoted to measuring and interpreting crystal‐size distributions. One of the reasons for the lack of pertinent texture data is perhaps the popularity of geochemical methods, which are fast and reliable, but need to be combined with digital image‐analysis techniques to permit quantification of rock texture.

1. Griffiths, 1952, AAPG Bulletin, v. 36, p. 205‐229. 2. Griffiths, 1961, J. Geol., v. 69, p. 487‐498.


23

Theme 2

Sedimentological studies


24

Timing of lacustrine expansion, sediment deposition and carbon drawdown during the early Toarcian Oceanic Anoxic Event (~183 Ma)

Ruhl, M.1,2,* & Xu, W.2, Hesselbo, S.P.3, Jenkyns, H.C.2

*[email protected]

1Department of Geology, Trinity College Dublin, The University of Dublin, Dublin 2, Ireland

2Department of Earth Sciences, University of Oxford, Oxford OX1 3AN, UK 3Camborne School of Mines, University of Exeter, Penryn TR10 9FE, UK

The early Toarcian Oceanic Anoxic Event (T‐OAE; ~183 Ma) was marked by persistent marine anoxia–

euxinia and globally significant burial of organic carbon in organic‐rich black shales, associated with a

major global carbon cycle perturbation likely linked to Karoo‐Ferrar volcanism1, 2, 3. Although the T‐

OAE is well studied in the marine realm, a new study shows that also continental interiors are

marked by significant climatic and environmental changes at that time4. Enhanced hydrological

cycling under elevated atmospheric pCO2 led to enhanced precipitation, resulting in major lake

systems developing in continental interiors coevally with the T‐OAE.

Increased lacustrine organic productivity from elevated riverine nutrients supply caused massive

burial of organic carbon in the Sichuan Basin alone, presenting an important negative feedback in

the global exogenic carbon cycle. Rhythmic changes in depositional conditions and sediment supply

and preservation, observed along a depth transect in the basin, occur possibly on astronomical time‐

scales allowing for high‐resolution temporal constraints. It suggests precession‐controlled changes in

lake‐level and organic productivity during the Early Toarcian OAE in the lacustrine Sichuan Basin.

1. Hesselbo, S.P., Grocke, D.R., Jenkyns, H.C., Bjerrum, C.J., Farrimond, P., Bell, H.S.M., Green, O.R., Massive

dissociation of gas hydrate during a Jurassic oceanic anoxic event, Nature 406: 392–395 (2000). 2. Jenkyns,

H.C., Geochemistry of oceanic anoxic events, Geochem. Geophys. Geosyst. 11 (2010). 3. Xu, W., Mac Niocaill,

C., Ruhl, M., Jenkyns, H.C., Riding, J.B., Hesselbo, S.P., Magnetostratigraphy of the Toarcian Stage (Lower

Jurassic) of the Llanbedr (Mochras Farm) Borehole, Wales: basis for a global standard and implications for

volcanic forcing of palaeoenvironmental change, Journal of the Geological Society, London, in press. 4. Xu, W.,

Ruhl, M., Jenkyns, H.C., Hesselbo, S.P., Riding, J.B., Selby, D., Naafs, B.D.A., Weijers, J.W.H., Pancost, R.D.,

Tegelaar, E.W., Idiz, E.F., Carbon sequestration in an expanded lake system during the Toarcian oceanic anoxic

event, Nature Geoscience 10, 129–134 (2017).


25

A new theoretical framework for the transfer of periodic environmental signals to the stratigraphic record.

Stephan Toby1, Rob Duller1*, Silvio De Angelis1, Kyle Straub2

*[email protected]

1University of Liverpool, Liverpool, UK

2Tulane University, New Orleans, Louisiana, USA

The stratigraphic record is a unique physical archive for past environmental forcing on Earth and

other planetary bodies. This forcing sets the rate and volume of sediment delivered to sedimentary

basins, which should be recorded in the stratigraphic record. However, for sediment supply signals

to make their way through to stratigraphy, they must pass across and through the active layer of the

Earth’s surface. Within this active layer, autogenic processes govern storage and release of

sediment, which distort environmental signals as they are transferred across the surface and to the

stratigraphic record; therefore any interpretation of the stratigraphy cannot be guaranteed to reflect

past environmental signals. To address this we develop a new theoretical framework and new

stratigraphic stability diagram for sedimentary systems. This novel framework is specifically designed

to assess the ability of a depositional landscapes to store environmental signals emanating from

catchments or from a point source. It is anticipated that this approach can realistically be applied to

field stratigraphy in order to guide a more reliable diagnosis of ancient environmental signals.


26

Porosity of uniform sands and gravels as a function of packing state and particle properties (size, roundness and sphericity)

Gert Jan Weltje1*

*[email protected]

1 KU Leuven, Department of Earth and Environmental Sciences, Celestijnenlaan 200E, 3001 Leuven‐

Heverlee, Belgium

The ability to predict the porosity of sediments with arbitrary size‐roundness‐sphericity distributions

has remained one of the elusive goals of sedimentology. It is proposed that this complex problem

may be broken down into a series of sub‐problems, which must be resolved sequentially: (1) predict

the porosity of arbitrary uniform particle assemblages (i.e., particles with fixed size, roundness and

sphericity) under specified experimental conditions; (2) predict the porosity of arbitrary mixtures of

uniform particle assemblages under specified experimental conditions (this is where grain‐size and ‐

shape distributions come in); (3) relate the experimental conditions to the evolution of boundary

conditions over the course of geological time and use this to predict how porosity will evolve (this is

where burial history and diagenesis come in). Not much is known about the first sub‐problem,

although a considerable amount of empirical data relevant to its resolution are available in the field

of geotechnical engineering. The second sub‐problem has been extensively studied in the field of

powder technology. The third poses many problems. In geology, it has been dealt with in a highly

generic way only, i.e. without specification of the properties of particle assemblages, and is

therefore regarded as essentially unresolved.

In this contribution a solution to the first sub‐problem will be presented. Legacy data were culled

from a range of mostly geotechnical sources, published between 1938 and 2017, and analysed in the

light of a new porosity model. Analysis of this heterogeneous data set has been carried out by

capturing the variability among experimental conditions with a single number, termed the reference

porosity (or packing state) of a particle assemblage. The porosity of uniform particle assemblages

corresponding to a given reference porosity has been termed the intrinsic porosity. Available data

permit an intrinsic porosity function to be derived for grain assemblages in the sand‐to‐gravel range

with any combination of roundness and sphericity values, which have been deposited in air. With

this function, the porosity of arbitrary uniform particle assemblages can be predicted quite

accurately (within about 2% absolute error) if the reference porosity is known. The geological

significance of the reference porosity lies with the fact that it reflects the conditions under which

deposition occurs. Hence, accurate and precise porosity prediction requires knowledge of the

reference porosities of depositional (sub) environments. Such knowledge is presently unavailable,

despite its obvious relevance to sedimentological, diagenetic and hydrogeological studies.


27

KEYNOTE Grave to Cradle: Accounting for Sediment Genetics in Hydrocarbon

Exploration

William A. Heins

[email protected]

ExxonMobil Exploration Co., 22777 Springwoods Village Pkwy, Spring, Texas, USA 77096

Mass‐balance analysis can be used to increase the probability that all the sources (and their relative

contribution) to a sedimentary sink have been accounted for. If the sources are all accounted, then

any observation about one part of the source‐sink system will provide insight into, or constraint

upon, every part of the system. The most useful mass‐balance analysis must start with a strict

definition of the target sediment body in the sink, formally quantify and account for uncertainties

around volume estimates, and end with a probabilistic evaluation of all available sources against

the sink.

Starting with the sink is important to ensure that potential intra‐ and extra‐basinal sources of

sediment are not overlooked, as illustrated with a recent exploration example from Mozambique

where there is about twice as much sediment in the basin as has been generated on the

immediately adjacent hinterland. Strict definition of the physical boundaries of the target sediment

body helps clarify the time and space requirements that sources must fulfil to be considered in the

analysis, as well as illuminating the potential for leakage out of the sink.

An example from the last 190k years (since MIS 6/7) of sedimentation on the Golo Fan off the

eastern coast of Corsica demonstrates that even with high data density in a well‐constrained

modern system it is impossible to know either the volume of sediment deposited in the sink or the

amount of sediment generated from the source precisely; the range from the minimum to the

maximum estimate is at least a factor of 2‐3, if uncertainties are honestly accounted and

propagated through the analysis. Given the imprecision of both source and sink volume estimates,

a balance between them can only be evaluated probabilistically.

The community should align on formal analytic procedures and strict accounting practices to realize

the potential of sink‐to‐source mass‐balance analysis.


28

Theme 3

Big data and automated data

collection


29

High-resolution reservoir quality prediction from cores by multifaceted analysis: a Carboniferous example from the Dutch offshore

Saturnina Henares1*, Menno R. Bloemsma2, Marinus E. Donselaar1,3, and Gert Jan Weltje1

*[email protected]

1 Division of Geology, KU Leuven, Celestijnenlaan 200e, 3001 Leuven, Belgium 2 Tata Steel Europe, Centre of Expertise Iron Making, PO box 10000, 1970 CA IJmuiden, The

Netherlands 3 Department of Geoscience and Engineering, Delft University of Technology, Stevinweg 1, 2628 CN

Delft, The Netherlands

In Reservoir Quality (RQ) studies, only cores provide an intact sample of the sedimentary rock, which

permits various parameters, such as mineralogical composition, texture, diagenetic alterations and

porosity‐permeability distribution to be measured. However, state‐of‐the‐art routine core analysis

(RCA) workflow for RQ prediction is still based on a mere collection of such measurements acquired

with different analytical techniques and at different resolutions/scales. This protocol does not

include operator‐bias evaluation and usually fails at integrating the continuous sedimentological

core description with spot measurements on plugs and thin sections. Moreover, RCA data rarely

have verified uncertainty specifications, thus hampering statistically‐rigorous extrapolation of spot

measurements such as petrographic description, to the entire reservoir volume.

Because many sediment properties are interrelated, e.g. porosity is governed by grain size

distribution, which in turn is related to mineralogical composition with a specific chemical

expression, an integrated analysis of all these data is the best way to understand and predict their

behaviour. Non‐destructive, in‐situ hyperspectral X‐ray fluorescence core‐scanning (XRF‐CS)

technology provides a spatially continuous, cm‐scale “big‐data” environment in which the

relationship between the different variables can be statistically explored.

Based on this approach, we have integrated the sedimentological description of a fluvial

Carboniferous core with the quantitative petrographic and chemical (i.e. inductively coupled plasma

optical emission spectrometry) analysis and plug‐derived poro‐perm measurements, using the XRF‐

CS output. The calibration (Weltje & Tjallingii, 2008; Weltje et al., 2015; Bloemsma, 2015) and

multivariate statistical analysis of these integrated data allowed us to identify the different

diagenetic zones affecting reservoir quality, and to predict their occurrence across three different

reservoir intervals. This is the first step of the so‐called Integrated Core Analysis (ICA) workflow that

we are developing, which intends to overcome some of the main abovementioned issues.

1. Weltje, G.J., & Tjallingii, R., Calibration of XRF core scanners for quantitative geochemical logging of

sediment cores: theory and application. Earth Planet. Sci. Lett., 274, (2008). 2. Weltje, G.J., Bloemsma, M.R.,

Tjallingii, R., Heslop, D., Röhl, U., & Croudace, I.W., in: Micro‐XRF studies of sediment cores (eds. Croudace,

I.W. & Rothwell, R.G.) 507‐534, (Springer Science+Business Media, 2015). 3. Bloemsma, M.R., Development of

a modelling framework for core data integration using XRF scanning. PhD thesis. 229 pp.

Acknowledgements

We gratefully acknowledge Wintershall Noordzee, NAM, Shell, and EBN for financial support for this study. Core material for this study was kindly provided by Wintershall Noordzee BV.


30

Using “virtual microscopy” to re-imagine and revitalize petrographic analyses

Suzanne Kairo1* and Christopher M. Prince2

*[email protected]

1Unaffiliated,627 Bayland Avenue, Houston, TX 77009, USA

2PetroArc International, 1095 Evergreen Circle, The Woodlands, TX 77380, USA

The process of collecting data from thin‐sections has remained essentially the same over the last 100

years. Over the past two decades, digital photomicrography has made it possible to routinely make

co‐registered images of entire petrographic thin sections, digitized at high magnification under

multiple light sources, creating a “digital thin section”. Using “virtual microscope” software, the

images can be viewed and analyzed using desktop computer, laptop or tablet.

MicroPet is an example of a virtual microscope system containing a suite of tools customized for

routine petrographic analysis. MicroPet makes easy work of setting up modal analysis grids or

transects and conducting conventional studies like compositional and grain size point counts. The

petrographer still needs to use experience and intelligence to make a standardized identification of

rock components, but precise dimensional measurements are made using a mouse. MicroPet

automatically saves all the information along with a record of the exact position of the data point on

the image, thus creating a high‐resolution record of the analysis. This provides visual and digital

documentation of every observation. Virtual thin sections and their registered data can be shared

electronically by co‐workers and collaborators. Data can be reviewed, interrogated, and edited. Due

to the rigorous documentation afforded by digital images and digital data capture, virtual

microscopy has the potential to turn the art of petrographic thin‐section analysis into a technique

that is quantifiable, verifiable and repeatable. In addition, virtual microscopy enables the use of

image analytic methods to efficiently quantify heretofore unquantifiable petrologic characteristics.

There are many elements of virtual microscopy that make it appealing as an innovative way to

conduct petrographic studies. It is fast and efficient. It greatly reduces the tedium and uncertainty of

quantitative data collection. Digital photomicrographs of an entire thin‐section, a target area, or

selected features can be taken in just seconds with perfect lighting and focus and saved with the rest

of the sample data. The virtual microscope can be used in your office, at home or in the field. Since

samples are digital they can be stored and shared as such, eliminating the mishandling of precious

physical samples.

The process of obtaining the quantitative data, so often fundamental to provenance and sediment

generation studies, is made more practical, more efficient, and even more enjoyable though virtual

microscopy and digital thin sections. Applications of this innovative approach are limited only to the

imagination.


31

High resolution heavy mineral analysis by automated Raman spectroscopy

N. Keno Lünsdorf1*, Jannik Kalies1, Patrick Ahlers1, István Dunkl1 and Hilmar von Eynatten1

*[email protected]

1Department of Sedimentology and Environmental Geology, Georg‐August‐University Göttingen,

Goldschmidtstr. 3, 37077 Göttingen, Germany

Identification and characterization of heavy minerals is one of the fundamental techniques in

sedimentary provenance analysis and optical microscopy the tool of choice. However, optical

identification depends on operator experience and tends to be biased by subjectivity. Typically, 200

transparent heavy minerals are counted implying that mineral species of low abundance might not

be detected and opaque heavy minerals are ignored. Modern Raman spectrometers are highly

automatable and can help to mitigate the mentioned issues1. The method presented is a point count

approach which starts by using a polarizing microscope to create high resolution mosaic images of a

polished mount in transmitted and reflected light at high magnification. From this mosaic the

measuring positions of opaque and transparent heavy minerals are selected and transferred to the

Raman spectrometer. Depending on the heavy mineral assemblage, about 400 to 800 grains can be

measured per hour. A measuring routine has been designed to change the measuring parameters

according to the type of grain (opaque vs. transparent) to ensure high quality spectra. A modified

and extended version of the Rruff database2 is used in conjunction with the segmental hit quality

index3 approach to automatically identify the mineral phases. Automated deconvolution4 can be

applied to specific mineral groups (e.g. garnet, olivine, pyroxene) to estimate chemical composition

within solid solution series. As grains are referenced, specific interesting phases can be selected and

easily transferred to other analytical machines (e.g., electron microprobe or LA‐ICPMS) in order to

perform single grain chemical or geochronological analysis.

1. Andò, S. & Garzanti, E., in Sediment Provenance Studies in Hydrocarbon Exploration and Production (eds. Scott, R., A., Smyth, H., R., Morton, A., C. & Richardson., N.) 395‐412, (Geological Society, London, Special Publications, 2014).

2. Lafuente, B., Downs, R. T., Yang, H. & Stone, N., in Highlights in Mineralogical Crystallography (eds. Armbruster, T. & Danisi, R., M.) 1‐30, (W. De Gruyter, 2015).

3. Park, J.‐K., Park, A., Yang, S., K., Baek, S.‐J., Hwang, J. & Choo, J., Raman spectrum identification based on the correlation score using the weighted segmental hit quality index. Analyst. 142, (2018).

4. Lünsdorf, N., K. & Lünsdorf, J., O., Evaluating Raman spectra of carbonaceous matter by automated, iterative curve‐fitting. International Journal of Coal Geology, 160‐161, (2016).


32

Automated data collection and analysis, current capability and future potential: Example of a 1000 sample QEMSCAN dataset.

Jenny Omma1*

*[email protected]

1Rocktype Ltd, 87 Divinity Road, Oxford, OX4 1LN

Automated, digital petrographic* data collection allows for the generation of Big Data petrographic datasets, orders of magnitude larger than previously feasible. Creating larger, more statistically robust datasets greatly enhances our ability to detect relevant signals in the noise of petrographic data. Advanced data analytics methods, currently employed in other industries tasked with prediction (such as insurance, marketing, finance) is poised to revolutionise our ability to extract insight from rocks. This digital transformation of rock characterisation is currently underway in the Oil & Gas industry, with some large operating companies and many smaller consulting companies leading the way. Work is underway to train computers to carry out optical point counting, to upscale mineralogical information to basin scale seismic data and to create global, data driven provenance models. As scientists working within the field of sediment generation and provenance analysis, we have the opportunity to engage with and steer these efforts, to improve the veracity and impact of these emerging workflows. In this talk, I aim to provide an overview of current capability within the field of automated, petrographic data collection and show an automatically generated dataset, a 1000 sample QEMSCAN study from the Barents Shelf. I will highlight current trends in the automation of petrographic data collection and analysis and suggest ways we can be involved in this field. *term used generally, to mean the study of rock or rock constituents.


33

KEYNOTE Decoding transient tectono-climatic signals from the sedimentary record

Alexander C Whittaker1*

*[email protected]

1Department of Earth Science and Engineering, Imperial College, London, UK

Both tectonics and climate profoundly influence the erosional‐depositional processes that shape

the Earth’s surface. Moreover, the magnitude, locus and characteristics of sediment export from

catchments to basins play a fundamental role in determining depositional stratigraphy1. While

progress has been made in understanding the transient responses of landscape systems to

tectonics and the sediment flux history this represents, the extent to which the Earth’s surface is

either sensitive, or buffered, to rapid climate change remains extremely contentious2. In principle, a

good way to address this fundamental question empirically is to examine the sedimentary record,

because this constitutes the only physical archive we have of mass transport across Earth’s surface

as a function of tectonic or climatic perturbation in the past.

Here I examine how field observations and numerical modelling techniques can be used to

constrain how sediment routing systems are influenced by tectono‐climatic perturbation, and the

circumstances in which depositional stratigraphy can be ‘decoded’ for these driving forces. In

particular, the use of self‐similarity and mass balance approaches are increasingly powerful tools to

recover tectono‐climatic signals from sedimentary archives in time and space3, 4. Field examples

from California and the Mediterranean explore the extent to which we can now quantitatively

“invert” stratigraphy for tectonic or climatic forcing, and highlight some of the problems that still

remain e.g., 5.

1. Whittaker, A. C., Attal, and Allen, P. A., Characterising the origin, nature and fate of sediment exported

from catchments perturbed by active tectonics, Basin Research, 22, (2010). 2. D’Arcy M. & Whittaker, A. C.,

Geomorphic constraints on landscape sensitivity to climate in tectonically active areas, Geomorphology, 204,

(2014). 3. Armitage, J. A., Duller R. A., Whittaker, A. C., and Allen, P. A., Transformation of tectonic and

climatic signals from source to sedimentary archive, Nature Geoscience, 4, (2013). 4. Michael, N. A.,

Whittaker, A. C. Allen P. A., The functioning of sediment routing systems using a mass balance approach:

Example from the Eocene of the southern Pyrenees, Journal of Geology, 121, (2013). 5. D’Arcy, M.,

Whittaker, A. C., Roda‐Boluda, D. C., Measuring alluvial fan sensitivity to past climate changes using a

self‐similarity approach to grain size fining, Death Valley, California, Sedimentology, 64, (2017).


34

Theme 4

New Approaches to Sedimentary

Provenance


35

Testing the utility of apatite fluorine and chlorine content in sediment source tracking

Claire Ansberque*, Chris Mark, John Caulfield and David Chew

* [email protected]

Department of Geology, Museum Building, Trinity College Dublin, College Green, Dublin, Ireland

Apatite is an accessory mineral that is widely present in most igneous and metamorphic rocks, and is

sufficiently resistant to transport and weathering processes to be a common detrital component in

clastic rocks. As apatite typically incorporates U and Th at sufficient concentration to enable U‐Pb,

fission‐track, and (U‐Th)/He thermochronometry, it is a commonly used phase in detrital provenance

studies. In addition, apatite also incorporates a wide range of trace elements at concentrations

readily detectable by routine laser ablation (quadrupole) inductively coupled plasma‐mass

spectrometry (LA‐Q‐ICPMS) analysis (e.g. Sr, Y, and REE), which can also yield diagnostic provenance

information. However, detrital thermochronometry is of limited use in the case of source terrane(s)

with similar crystallisation or cooling ages, while many trace elements may yield non‐diagnostic

provenance information when their source rocks are lithologically similar or genetically related (e.g.,

a suite of granitoids). Here we present an alternative provenance approach using apatite fluorine

and chlorine, integrated with trace element analysis. Fluorine content was determined by SEM‐EDS

and chlorine and trace elements by LA‐Q‐ICPMS. We apply this method to apatites from five late‐ to

post‐tectonic Caledonian granitoids which have closely‐spaced crystallisation and cooling ages,

rendering discrimination of their detrital contribution challenging using conventional

thermochronometry, and on U‐Pb dated apatites from modern sediment from the Spey River.

Results show that each granitoid can be distinguished by its mean F and Cl abundances but not by

their REE patterns. Among the late Caledonian in age detrital apatites of the Spey, five potential

sources are identified by apatite Sr‐Y‐REE patterns within which some additional sources can be

proposed by analysing their F‐Cl concentrations. Therefore, combining apatite fluorine, chlorine and

trace element analysis is an approach with strong potential for discriminating igneous source rocks

with either similar crystallisation/cooling ages and/or trace element patterns in detrital provenance

studies.


36

Effective mineral quantification for arkosic sandstones using SEM imaging and element mapping ahead of common Pb isotopic analysis

Sebastian Zimmermann1, *, Peter Haughton1, Shane Tyrrell2

*[email protected]

1iCRAG & UCD School of Earth Sciences, University College Dublin, Dublin 4, Ireland.

2iCRAG & Earth & Ocean Sciences, School of Natural Sciences, NUI Galway, Galway, Ireland.

Detrital mode studies of sandstone thin sections are one of the most widely used tools to

interpret clastic sedimentary provenance. Petrography is a quick and cost‐effective approach

that requires only an optical polarising microscope. The challenge comes when characterising

sandstones with significant feldspar. Although both plagioclase and K‐feldspar can be stained,

commonly this is undertaken just for the K‐feldspar. Plagioclase which is more difficult to stain

may thus go undetected and potentially is misassigned to quartz, especially if untwinned. As K‐

feldspar can be extensively albitised on burial, this is particularly an issue with deeply buried

arkoses. Loss of K‐feldspar with depth has been widely reported and is potentially important for

the development of secondary porosity and liberation of ions for diagenetic reactions. It may

also systematically modify the framework composition of sandstones, mimicking provenance

changes. The present study is examining a related issue, whether or not the selective loss of K‐

feldspar can bias the range of Pb isotopic compositions of the feldspars measured in deeply

buried sandstones. The study is targeting the Middle Jurassic Fulmar Formation in the Central

North Sea where shallow‐marine sandstones were buried to depths ranging between 3 and 6 km.

Previous studies1,2 have shown progressive loss of K‐feldspar with burial in the same area.

Sandstones sampled across a range of burial depths have been characterised using a novel

imaging and point counting technique. BSE SEM imaging of polished thick sections combined

with element mapping using a Hitachi‐tabletop‐SEM followed by on‐screen gridding and

quantification of the grain assemblage confirms the framework mineralogy changes with

increasing depth. K‐feldspar accounts for >40% by total volume at 3.2 km depth but only ~8% at

5.8 km depth. However, grain identification using the element mapping reveals that albite

increases from ~3% at 3.2 km to ~20% at 5.8 km, implying a role for albitisation of a significant

volume of K‐feldspar. Change in composition is accompanied by a progressive increase in

dissolution features in the remaining K‐feldspar. Fresh K‐feldspar grains reduce from >70% to

~7% of the K‐feldspar population with burial with a proportionate increase in corroded grains

(~10% to ~56%) and skeletal grains (0% to ~30%). Gridding of the imaged polished section allows

selected grains (including dissolved and skeletal grains) to be easily targeted by the laser ablation

system for Pb isotopic analysis. Previously, reoccupying grains characterised separately using the

SEM has been a challenge, particularly in fine‐grained sandstones.

1. Parsons, I., Thompson, P., Lee, M.R., Cayzer, N., Alkali feldspar microtextures as provenance indicators

in siliciclastic rocks and their role in feldspar dissolution during transport and diagenesis. Journal of

Sedimentary Research 75, 921‐942, (2005). 2. Wilkinson, M., Haszeldine, R.S., Morton, A., Fallick, A.E.,

Deep burial dissolution of K‐feldspars in a fluvial sandstone, Pentland Formation, UK Central North Sea.

Journal of the Geological Society 171, 635‐647, (2014).


37

Babel or Esperanto? The need of finding a common language in heavy mineral analyses

István Dunkl*1, Hilmar von Eynatten1, Keno Lünsdorf1, Sergio Andò2, Andrew C. Morton3

*[email protected]‐goettongen.de

1 University of Göttingen, Geoscience Center, Department of Sedimentology and Environmental

Geology, Göttingen, Germany

2 University of Milano‐Bicocca, Department of Earth and Environmental Sciences, Laboratory for

Provenance Studies, Milan, Italy

3 HM Research Associates, Giddanmu, St Ishmaels SA62 3TJ and CASP, University of Cambridge,

Madingley Rise, CB3 0UD, UK

Similar to the standardization efforts performed regularly in technical and chemical research, some

branches of analytical geosciences have conducted interlaboratory comparisons by circulating either

well certified or well homogenized standard samples. Without these certified natural reference

materials, routine analyses using methods such as U‐Pb, K‐Ar, fission track and helium

geochronology, coal petrography, illite "crystallinity" and many other geochemical analytical

techniques would be impossible.

In the field of sediment provenance studies, heavy mineral analysis plays a prominent role.

Perspectives have been recently widened with development of advanced spectroscopic techniques

such as Raman and automated procedures, which generate much higher numbers of observations

than the classical technique based on polarizing microscopy. In this way the statistical robustness of

the HM proportions and HM ratios can achieve significant improvements. However, automated

procedures may suffer from distinct shortcomings and a systematic comparison of different

laboratories and different techniques have not been performed so far.

We organized a round robin test and distributed two different heavy mineral concentrates to over

forty laboratories. The goals of the interlaboratory test are (i) to outline the reproducibility and

comparability of heavy mineral analyses, and (ii) compare the different techniques. We did not use

natural HM samples in order to avoid the influence of polyphase (composite) grains, which may be

treated differently by the users and thus introduce some subjectivity to the measurements. Instead,

the mixtures were made from high purity monomineralic components, mostly from crushed

monocrystals. In order to mimic the usual appearance of detrital grains, air abrasion was applied on

most of the monomineralic samples to produce more‐or‐less rounded grains. The heavy mineral

concentrates were sieved to 63‐125 µm size fraction. Precisely weighted masses of the different

monomineralic components were mixed.

The participants were asked to apply their usual techniques to the test samples, report their

procedure, the degree of experience of the observer, the heavy mineral counts and, separately,

opaque, lithic fragments and unidentified grains. The results will be presented anonymously, and for

the first time at the Dublin WGSG meeting.


38

A workflow for analysis of compositional data in sedimentary petrology: inferring provenance changes in sedimentary basins from spatio-temporal

variation in heavy-mineral assemblages

Jasper Verhaegen1*, Gert Jan Weltje1

*[email protected]

1University of Leuven, Department of Earth and Environmental Sciences, Celestijnenlaan 200E, 3001

Heverlee, Belgium.

In the past century, a wealth of sediment‐petrological data was collected. These legacy datasets

were analysed with classic data analysis techniques and are often not reanalysed prior to sample

collection for new research. Such legacy datasets could still reveal a wealth of information if they are

analysed with modern statistical methods. Sediment‐petrological or geochemical data are mostly

compositional data, which often still pose a problem for correct data analysis. Due to their constant‐

sum constraint and non‐negativity, classic statistical analysis cannot be correctly performed. These

problems can be overcome by applying a log‐ratio transformation1. Ratios do not suffer from a

constant‐sum constraint and by applying a logarithmic transformation the data can theoretically vary

between minus infinity and infinity.

In this study, a heavy mineral database of Miocene sediments from the southern North Sea Basin is

analysed². In the 20th century, many heavy mineral data were collected. These data were mostly

used as qualitative indications for stratigraphy and provenance and not incorporated in a

quantitative provenance methodology. Even today, such data are often portrayed in cumulative

diagrams as a qualitative indication of variation. A straightforward workflow for the analysis of such

large compositional databases is proposed, consisting of (1) a centred log‐ratio transformation to fix

the constant‐sum constraint and non‐negativity of the compositional data, (2) a cluster analysis of

the transformed data, (3) principal component analysis of the transformed data and (4) bivariate log‐

ratio plots. Several (5) proxies for the effects of sorting and weathering are included to check the

provenance significance of observed variations and finally (6) a spatial interpolation of a provenance

proxy extracted from the data set is carried out.

The results obtained are used to gain improved insight into Miocene sediment provenance variations

in the study area. This study also showcases the value of this approach in uncovering new

provenance details from legacy datasets or for quick analysis of new datasets. The database used

does lack good time and depth information, which limits the resolution and accuracy of the model.

Also, due to the lack of grain size information, variations in mineral content linked to grain size

variations cannot correctly analysed. In the next phase of this research, a comprehensive multi‐proxy

approach ‐ which includes heavy mineral data, grain size data, biostratigraphy, geochemical data and

Zr U/Pb data ‐ is applied to account for hydraulic effects and to add a good temporal framework to

the model.

1. Aitchison, J., The statistical analysis of compositional data. Chapman and Hall, London, (1986). 2. Geets, S. &

De Breuck, W., De zware‐mineraleninhoud van Belgische mesozoïsche en cenozoïsche afzettingen. Neogeen.

Natuurwetenschappelijk Tijdschrift. 73, (1991).


39

How to average point-counting data

Pieter Vermeesch1*

*[email protected] 1Department of Earth Sciences, University College London

The mineralogical composition of silicilastic sediments can be determined by tallying the occurrence of various

minerals in a representative sample of (200‐400, say) grains1, 2. Despite the widespread use of this type of data

in sedimentary geology, their statistical analysis is demonstrably underdeveloped. For example, there currently

exists no agreed method to average multi‐sample point‐counting datasets, or to quantify point‐counting data

dispersion. Traditionally, these operations were done by taking the arithmetic mean and standard deviation,

respectively. Unfortunately, this may easily produce non‐sensical results. For example, Weltje2 shows that the

common practice of using ‘2‐sigma’ confidence bounds around the arithmetic mean can produce physically

impossible negative values when applied to petrographic point‐counts. To solve these problems, Weltje2

argues that point‐counts should be treated as compositional data, which are defined as “vectors representing

parts of a whole that only carry relative information”3. Aitchison4 shows that the statistical analysis of such

data is best carried out using a simple logratio transformation. This procedure yields geologically meaningful

(geometric) means and confidence regions. Weltje2’s adoption of logratio statistics to point‐counting data

represents a huge improvement over the ‘crude’ statistics employed previously. But it does not solve all our

problems. There are two crucial differences between point counts and the classical compositional data

discussed by Aitchison4.

First, point‐counting data often contain zero values. These are incompatible with the log‐ratio transformation.

Second, point‐counting data are associated with significant counting uncertainties, which are ignored by

classical compositional data analysis. For a single sample, this uncertainty is adequately described by

multinomial counting statistics [Section 6 of ref. 2]. But for larger datasets comprised of multiple samples,

existing procedures to construct confidence regions [as discussed in Section 7 of ref. 2] are inadequate

because they lump together the ‘observational’ dispersion caused by counting statistics and the true

‘geological’ dispersion. This long standing problem can be solved using established statistical methods adopted

from the work of Galbraith5 in fission track geochronology. The fission track method is based on the ratio of

the number of spontaneous 238U‐tracks to the number of neutron‐induced 235U‐tracks per unit area in

accessory minerals such as apatite or zircon. This is equivalent to a simple two‐component point‐counting

problem. This equivalence can be used to derive the concept of a ‘pooled composition’, which represents the

most reliable (in terms of accuracy and precision) average of homogeneous point‐counting data.

The analytical uncertainty of individual point‐counting proportions may vary greatly between samples. The

radial plot is an effective graphical means of visualising such ‘heteroscedastic’ data5. Originally developed for

fission track data, radial plots can also be used to display point‐counting ratios such as apatite/tourmaline,

epidote/garnet, etc. Radial plots allow a visual assessment of the degree to which counting uncertainties can

explain the observed scatter between multiple ratio estimates. This assessment can be formalised by a chi‐

square test for compositional homogeneity. Multi‐sample datasets that fail the chi‐square test are said to be

‘overdispersed’ with respect to the counting uncertainties. The degree of overdispersion may be quantified by

means of a continuous mixture model. This model leads to the concept of a ‘central composition’ as a better

alternative to the pooled composition for most datasets.

1. Van der Plas, L. & Tobi, A. A chart for judging the reliability of point counting results. American Journal of Science 263,

87–90 (1965). 2. Weltje, G. Quantitative analysis of detrital modes: statistically rigorous confidence regions in ternary

diagrams and their use in sedimentary petrology. Earth‐Science Reviews 57, 211 – 253 (2002). 3. Pawlowsky‐Glahn, V. &

Buccianti, A. Compositional data analysis: Theory and applications (John Wiley & Sons, 2011). 4. Aitchison, J. The statistical

analysis of compositional data (London, Chapman and Hall, 1986). 5. Galbraith, R. F. Statistics for fission track analysis (CRC

Press, 2005).


40

Sedimentary provenance analysis meets ultrahigh-pressure research

Jan Schönig1*, Guido Meinhold1,2, Hilmar von Eynatten1, & Nils K. Lünsdorf1

*jan.schoenig@uni‐goettingen.de

1Department of Sedimentology and Environmental Geology, Geoscience Center Göttingen, University

of Göttingen, Goldschmidtstraße 3, 37077 Göttingen, Germany

2School of Geography, Geology and the Environment, Keele University, Keele, Staffordshire, ST5 5BG,

UK

The term ultrahigh‐pressure (UHP) metamorphism refers to crustal rocks which experienced

pressure–temperature conditions high enough for the formation of coesite1, i.e., pressures of

>2.7 GPa at 700°C2. Finding traces in the geological record is of first‐order significance because UHP

metamorphism is directly interlinked with deep subduction processes exceeding 100 km of

subduction depth3. Thus, tracing UHP rocks and their corresponding terranes, determining their

areal extent and geodynamic context, and dating these events has significant implications for, inter

alia, our understanding of subduction tectonics and geochemical recycling in Earth history4. The field

of UHP research, however, was so far almost exclusively examined by specialists in metamorphic

petrology, who analyze thin sections of crystalline rocks, which have been sampled for the highest

potential to be equilibrated under UHP conditions (mainly eclogites). This traditional method suffers

from (i) being restricted to UHP rocks that still exist and are exposed at the Earth’s surface, (ii)

overlooking potential rocks in the field due to overprinting (especially felsic rocks), alteration, soil

cover, or other obstacles, (iii) subjective selection of samples, (iv) sampling only very small spots

from potentially huge rock volumes, (v) overlooking UHP indicators other than coesite which

(partially) transformed to quartz and show typical radial expansion fractures, including

monomineralic coesite, and (vi) preparing just a few thin sections from sampled rocks, which

altogether implies a high probability of missing the relevant structures.

Here we present types and distribution of mineral inclusions in detrital garnets from a modern sand

sample taken at the island of Runde, which is located in the Western Gneiss Region of SW Norway.

All mineral inclusions ≥2 µm in ~150 fine‐ to medium‐sand sized garnet grains were identified by

Raman spectroscopy. The specific search for UHP mineral inclusions was extended to a total of ~730

grains. Overall, 13 intact monomineralic coesite inclusions were detected in 6 of the analyzed host

garnets, which indicates the erosion of UHP rocks in the sampled catchment5. The combination of

geochemical garnet compositions and the distribution of all mineral inclusions suggest more than

one UHP source rock type, including mafic and felsic lithologies. The novel approach provides a

complementary and effective tool to capture the occurrence, distribution and characteristics of UHP

rocks at the catchment scale, overcomes the drawbacks given by analyzing only crystalline rocks, and

opens opportunities for sedimentary petrologists to shed new light on the field of UHP research.

1. Schertl, H.‐P. et al., Twenty‐five years of ultrahigh‐pressure metamorphism Preface. Eur. J. Mineral. 21,

1083–1084 (2009). 2. Bohlen, S. R., & Boettcher, A. L., The quartz–coesite transformation: A precise

determination and the effects of other components. J. Gephys. Res. 87, 7073–7078 (1982). 3. Stern, R. J.,

Evidence from ophiolites, blueschists, and ultrahigh‐pressure metamorphic terranes that the modern episode

of subduction tectonics began in Neoproterozoic time. Geology 33, 557–560 (2005). 4. Liou, J. G. et al.,

Ultrahigh‐pressure minerals and metamorphic terranes – the view from China. J. Asian Earth Sci. 35, 199–231

(2009). 5. Schönig, J. et al., Tracing ultrahigh‐pressure metamorphism at the catchment scale. Sci. Rep. 8, 2931.

doi:10.1038/s41598‐018‐21262‐8


41

Hydrated-heavy-mineral signature in orogenic sediments (Indus Fan, IODP Exp. 355)

Sergio Andò*, Wendong Liang, Mara Limonta, Chiara Ileana Paleari, Alberto Resentini, Eduardo

Garzanti

*[email protected]

University of Milano-Bicocca Department of Earth and Environmental Sciences, Laboratory for

Provenance Studies, Piazza della Scienza 4, 20126, Milan, Italy

Heavy‐mineral analysis represents a quantitative and valuable tool in high‐resolution provenance

study of modern and ancient sediments1.

After the analysis of sediments cored during IODP Expedition 355 in the Laxmi Basin, mineralogical

analyses were carried out to investigate and quantify the different compositional signatures of sand

and silt fractions in the Indus catchment and in deep‐sea turbidites of the Indus Fan.

Heavy minerals were recognized with a single grain approach, coupling classical optical and Raman

spectroscopy techniques on the very same detrital grains to identify epidote varieties in sand and

silt.

Amphibole and epidote group varieties can be discriminated according to the diagnostic position and

shape of the most intense OH‐ group stretching bands (frequencies between 3600 and 3700 cm‐1 are

particularly helpful).

An InVia RenishawTM apparatus, equipped with a green laser at 532 nm is used, reducing the

intensity of the laser down to 50% with an objective 50x LWD and exposure time of 0.5s for 60

accumulations, in the spectral region 3100‐4300 cm‐1. The uncertainty on the measured

wavenumbers was estimated as less than 1 cm‐1.

In the observed spectral region of OH‐ group stretching bands, a single peak is always visible and its

absolute position varies, resulting in a continuous shift of a mono‐peak in the region 3345‐3374 cm‐1

for clinozoisite, towards 3375‐3390 cm‐1 for epidote, together with increasing iron content. The

orthorhombic variety zoisite displays a different mono‐peak around 3163‐3169 cm‐1.

Preliminary data from fluvial and turbidite sediments document a rich and diverse heavy‐mineral

assemblage in both sand and silt fractions. The creation of an appropriate data base of Raman

spectra in this region is also prepared to apply routinely this method in future provenance studies of

fine sediments. Raman discrimination of hydrated heavy minerals such as the epidote group

represents a new tool for provenance research.

1. Andò, S. and Garzanti, E., Raman spectroscopy in provenance studies. Geological Society, London, 386, 395–412, (2014). 2. Pandey et al., Deep sea drilling in the Arabian Sea: constraining tectonic‐monsoon interactions in South Asia. International Ocean Discovery Program Expedition 355 Preliminary Report, 1–46, (2015).


42

Theme 5

Case Studies in Sedimentary

Provenance


43

Possibilities and limitations of multi-proxy detrital thermochronology: The Bengal and Indus Fans as archives of Himalayan exhumation

Chris Mark1*, Yani Najman2, Peter Clift3, Andrew Carter4, Dan Barfod5, David Chew1, Daniel Döpke1,

and Randall Parrish6

* [email protected]

1Dept. of Geology, Trinity College Dublin, Dublin, Ireland 2Lancaster Environment Centre, Lancaster University, Lancaster, UK 3Dept. of Geology & Geophysics, Louisiana State University, Baton Rouge, USA 4Dept. of Earth and Planetary Sciences, Birkbeck College, University of London, London, UK 5Argon Isotope Facility, Scottish Universities Environmental Research Centre, East Kilbride, UK 6British Geological Survey, Keyworth, Nottingham, UK and Department of Earth and Environmental

Sciences, University of Portsmouth, Portsmouth, UK

Around the Namche Barwa massif in the east, and the Nanga Parbat massif in the west, the trend of

the Himalayan orogen exhibits an abrupt change in orogenic strike from roughly E‐W to N‐S, forming

two structural syntaxes. Within each syntaxis, exposed crystalline basement of the underthrust

Indian plate exhibits granulite‐facies grade metamorphism, and records some of the fastest

exhumation rates observed on Earth (up to ca. 10 mm a‐1), together with Plio‐Pleistocene mineral

(re)crystallisation and cooling ages1,2. The cause(s) of this deep, rapid exhumation are controversial:

proposed explanations include (1) structural buckling of a pre‐existing indentor on the Indian plate3;

(2) geometrical stiffening driven by subduction geometry4; (3) focussing of exhumation by surface

processes such as the capture of the major trans‐Himalayan Yarlung‐Tsangpo and Indus drainages5;

and (4) orogen‐parallel strain partitioning6. Distinguishing between these hypotheses can in part be

achieved by constraint of the onset timing of rapid syntaxial exhumation.

Here, we present detrital rutile U‐Pb, white mica 40Ar/39Ar, and zircon fission track (ZFT) data from

samples collected from the Bengal fan during IODP expedition 354, and detrital rutile U‐Pb data from

samples collected from the Indus fan during IODP expedition 355. We discuss the implications of

these data for the exhumation history of the syntaxes. In addition, we highlight that

thermochronometer ages observed in detrital systems here and elsewhere do not necessarily match

those that would be expected based purely on known diffusion‐dominated temperature sensitivity

(e.g: rutile U‐Pb ages > white mica 40Ar/39Ar ages > ZFT ages). This may reflect biases including source

lithology, sedimentary processes, hydrologic sorting, or perhaps the operation of metamorphic

recrystallization as a driver of accessory phase age resetting7. We consider the implications for

future large‐scale detrital thermochronology studies.

1. Bracciali, L., et al., Earth‐Science Rev. 160, 350–385 (2016); 2. Crowley, J., et al., Earth Planet. Sci. Lett. 288,

408–420 (2009). 3. Burg, J., et al., Terra Nov. 9, 53–56 (1997); 4. Bendick, R., & Ehlers, T. A., Geophys. Res. Lett.

41, 5861–5867 (2014); 5. Zeitler, K. et al., Tectonics 20, 712–728 (2001); 6. Whipp, D., et al., J. Geophys. Res.

Solid Earth 119, 5077–5096 (2014). 7. Villa, I. M., Chem. Geol. 420, 1–10 (2016).


44

KEYNOTE The initiation and evolution of the Irrawaddy drainage, with implications

for the palaeo-drainage and crustal evolution of eastern Asia.

Peng Zhang1,2, Yani Najman2*, Lianfu Mei1*, Ian Millar3, Edward Sobel4, Dan Barfod5, Xiaolin Hu6

*[email protected] and [email protected]

1 Key Laboratory of Tectonics and Petroleum Resources (China University of Geosciences), Ministry

of Education, Wuhan 430074, China

2Lancaster Environment Centre, Lancaster University, Lancaster, LA1 4YQ, United Kingdom

3NERC Isotope Geoscience Laboratory, BGS Keyworth, Nottingham, NG12 5GG, United Kingdom

4Institut für Erd‐ und Umweltwissenschaften, Universität Potsdam, Karl‐Liebknecht‐Strasse 24‐25,

14476, Potsdam‐Golm, Germany

5Argon Isotope Facility, Scottish Universities Environmental Research Centre, Rankine Avenue,

Scottish Enterprise Technology Park, East Kilbride G750QF, United Kingdom

6Research Institute, China National Offshore Oil Corporation (CNOOC), Beijing 10027, China

Convergence and collision between the Indian and Eurasian plates during the Cenozoic produced

the Himalaya and Tibetan Plateau. Large fluvial drainages in this region may provide critical

information on crustal deformation and the degree of coupling between tectonics, climate and

erosion. The Central Myanmar Basin (Irrawaddy drainage basin), southeast of the eastern

Himalayan syntaxis, is characterized by a sequence of Cenozoic sedimentary rocks that archive the

evolution of the palaeo–Irrawaddy River. In this study we apply an integrated provenance approach

(zircon U–Pb and Hf, rutile U–Pb, mica Ar−Ar and bulk rock Sr–Nd isotopes) to these rocks to

document the initiation and development of the palaeo–Irrawaddy River. Our data show a major

change in provenance around the time of the Late Oligocene to Oligo−Miocene boundary.

Paleocene and Eocene samples have characteristics similar to the proximal Western Myanmar Arc

of the Central Myanmar Basin. Around the time of the Late Oligocene to Oligo‐Miocene boundary,

samples attain characteristics of the Mogok Metamorphic Belt, which is located in the headwaters

of the Irrawaddy catchment. We suggest the Paleocene to Eocene sediments were derived from

the proximal Western Myanmar Arc. The provenance change by the Miocene is likely to reflect

establishment of the palaeo–Irrawaddy through–going river, which began to flow from the Mogok

Metamorphic Belt highlands in the north of the drainage basin at this time. We see no evidence

that the palaeo–Yarlung River flowed into the Irrawaddy drainage as previously proposed by some

workers. Instead, we infer that the Indus–Yarlung Suture Zone was an internally–drained basin

during the Paleogene time prior to the palaeo–Yarlung River’s initiation as a major through–flowing

river to the Bay of Bengal via the Brahmaputra in the Miocene. Use of such rivers as monitors of

crustal deformation may need to be revised.


45

KEYNOTE A Neogene record of Himalayan erosion: the IODP Expedition 354 transect

in the Bengal fan at 8° N

Christian France‐Lanord*1, Volkhard Spiess2, Sébastien Lenard1, Albert Galy1, and Jérôme Lavé1

*[email protected]‐nancy.fr

1 CRPG, CNRS Université de Lorraine, Nancy France. 2 GeoB, Bremen University, Bremen Germany

Recent IODP Expedition 354 in the Bengal fan [1] generated a comprehensive record of Himalayan erosion over the Neogene and Quaternary. It documents the interplay between Himalayan tectonic and the monsoon. The Bengal fan is predominantly composed of detrital turbiditic sediments originating from Himalayan rivers, and transported through the delta and shelf canyon, supplying turbidity currents loaded with a wide spectrum of grain sizes. Turbiditic deposition makes that record at a given site is discontinuous which was the reason for an E‐W transect approach. Expedition 354 drilled seven sites along a 320 km E‐W transect at 8°N allowing the restitution of an almost complete record of Himalayan erosion at the scale of the Neogene. In spite of the transect extension, a long absence of deposition is observed between 0.6 to 1.2 Ma indicating that turbiditic depocenter was derived more to the West for ca. 600 kyr. Turbiditic sediments have close mineralogical and isotopic analogy with sediments of the modern Ganga‐Brahmaputra rivers. Major and trace element geochemistry show stable compositions throughout the Neogene and Quaternary with most variations controlled by the origin of eroded sources ie. the proportions of sediments derived from Himalaya and Transhimalaya. Although relatively stable, source tracers such as Sr‐Nd isotopic compositions and detrital carbonate compositions show organised variations with time. They imply that exposure to erosion of the different Himalayan formations has evolved as a result of the evolution of the thrusting structures. Data suggest that (1) a component derived from Tranhimalayan formation was present even during Lower Miocene, (2) the Tethys Himalaya exposure to erosion was higher during Miocene than during Pliocene and Pleistocene, and (3) that the exhumation of the Lesser Himalaya was initiated around 8 Ma. Coring of large sand samples also allowed to initiate cosmogenic 10Be tracing of erosion rates at the scale of the Ganga‐Brahmaputra basin. Relatively stable paleo‐concentrations reveal relatively steady erosion rates in spite of the Pleistocene climatic changes. Clays and major and trace element geochemistry reveal a very weak regime of chemical weathering with no significant variation through time. Concentrations in mobile elements such as Na and K relative to Al are significantly higher than in modern sediments suggesting that weathering or soil erosion is amplified in the modern time. Compositions are indeed controlled by source and weathering processes, but mineral sorting during turbiditic transport may also alter the geochemical signature of the sediments. Close attention has been given to evaluate the possible loss of clay size particles by large scale dispersion compared to silt and sand. It seems, however, that such processes cannot account for the differences observed with modern rive sediments. Low weathering of the sediments at 8°N indicates that erosion was dominated by physical processes and that transport is rapid enough to prevent evolution of particles in the floodplain. In the modern Himalaya, low weathering is achieved primarily by landslides and rapid transfer through the floodplain, i.e. limited recycling of sediment deposited in the floodplain. Both processes are favoured by the seasonality and the intensity of the monsoon. Overall, the low weathering intensity suggests that comparable erosion regime prevailed since at least the Early Miocene.

1. France‐Lanord, C., Spiess, V., Klaus, A., Schwenk, T., Expedition 354 Scientists. (2016). Proceedings of the

International Ocean Discovery Program (Vol. 354). http://doi.org/10.14379/iodp.proc.354.2016


46

Precisely constraining the timing of the India-Asia continental collision by provenance change

Xiumian Hu 1*, Wei An 2, Eduardo Garzanti 3, Jiangang Wang 4

*[email protected]

1 School of Earth Sciences and Engineering, Nanjing University, Nanjing 210023, China

2 School of Resources and Environmental Engineering, Hefei University of Technology, Hefei, 230009,

China

3Department of Earth and Environmental Sciences, Università di Milano‐Bicocca, 20126 Milano, Italy

4 Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100029, China

Placing precise constraints on the timing of the India‐Asia continental collision is essential to understand the successive geological and geomorphological evolution of the orogenic belt as well as the uplift mechanism of the Tibetan Plateau and their effects on climate, environment and life. Based on the extensive study of the sedimentary records on both sides of the Yarlung‐Zangbo suture zone in Tibet, we present state of knowledge on the timing of India‐Asia continental collision onset. By using the provenance change from Indian to Asian recorded by deep‐water turbidites near the suture zone, we constrain precisely collision onset as middle Palaeocene both from the Sangdanlin section (Hu et al., 2015) and the Mubala section. Marine sedimentation persisted in the collisional zone for another 20‐25 Ma locally in southern Tibet, and molassic‐type deposition in the Indian foreland basin did not begin until another 10‐15 Ma later (Hu et al., 2016, 2017).

1. Hu, X., Wang, J., An, W., Garzanti, E., & Li, J., Constraining the timing of the India‐Asia continental collision by the sedimentary record. Science China Earth Sciences, 2017, 60: 603‐625. 2. Hu X., Garzanti E., Wang J., Huang W., An W., Webb A., The timing of India‐Asia collision onset – facts, theories, controversies. Earth‐Science Reviews, 2016, 160: 264–299. 3. Hu, X., Garzanti, E., Moore, T., and Raffi, I., Direct stratigraphic dating of India‐Asia collision onset at the Selandian (middle Paleocene, 59 ± 1 Ma).: Geology, 2015, 43: 859‐862.


47

Mixing it up: Source switching in the Late Jurassic-Early Cretaceous Scotian Basin, offshore Nova Scotia revealed by multi-proxy provenance

analysis

Aoife Blowick*1, Georgia Pe‐Piper2, David Piper3 and Shane Tyrrell1

*[email protected]

1 Sediment Origins Research Team (SORT), Earth and Ocean Sciences and Irish Centre for Research in Applied Geosciences (iCRAG), National University of Ireland, Galway.

2 Department of Geology, Saint Mary’s University, Halifax, Nova Scotia B3H 3C3, Canada.

3 Natural Resources Canada, Geological Survey of Canada (Atlantic), Bedford Institute of Oceanography, P.O. Box 1006, Dartmouth, Nova Scotia, B2Y 4A2, Canada.

The Scotian Basin, offshore southern Nova Scotia, presents an exciting challenge in determining

sedimentary provenance given that the offshore sink parallels the strike of hinterland source

terranes, resulting in large quantities of polycyclic material being delivered to the offshore. A multi‐

proxy approach, wielding the benefits of signals from both labile and more robust minerals, must

therefore be employed to decipher first‐cycle versus multi‐cycle components. The current study

builds upon previous geochemical, geochronological and petrographic analysis of Late Jurassic‐Early

Cretaceous deltaic sandstones by fingerprinting Pb isotopes in detrital feldspar in order to help

constrain first‐cycle supply.

The Late Jurassic‐Early Cretaceous Scotian Basin experienced a four‐fold increase in siliclastic supply,

driving major deltas, which today host notable oil and gas reserves, to prograde across the basin

floor. Determining the source(s) of these sandstones can help to constrain both the timing and

location of hinterland uplift, and the extent and relative contribution of individual river systems. In

this way we can gain a better understanding of the main driver(s) behind such an abrupt change in

sediment flux.

On‐going characterisation of detrital K‐feldspar across the entire basin reveals a clear switch from

local Appalachian to long‐distance Grenville sources across the Jurassic‐Cretaceous boundary, a

signal partially obscured elsewhere in other trace components due to recycling and/or diagenetic

alteration. Such a switch in first‐cycle supply is consistent with rift flank uplift to the north‐east of

the drainage basin associated with the opening of the North Atlantic, and not isolated, localised river

capture and drainage re‐organisation. Instead, the Pb isotopic compositions are consistent with

previous studies indicating multiple active paleo‐river systems which responded in time to the rising

flank uplift to the north. First‐cycle supply from proximal sources in outboard Appalachian terranes

were delivered by small, local rivers in the east and west of the basin, whereas in the central Sable

and eastern Abenaki depocentres, more long‐distance sourcing from older Grenvillian rocks to the

north is indicated by a single increasingly abundant Pb population, raising important questions about

the independent roles of the paleo‐Sable and paleo‐Banquereau rivers. These preliminary results

demonstrate the importance of coupling individual tracers of varying resilience to unravel

sedimentary provenance.

This research is supported in part by a research grant from Science Foundation Ireland (SFI) under Grant

Number 13/RC/2092 and is co‐funded under the European Regional Development Fund, by PIPCO RSG and its

member companies, and by the Nova Scotia Offshore Energy Research Association (OERA).


48

The initiation and evolution of the river Nile

Laura Fielding12*, Yani Najman1, Ian Millar3, Peter Butterworth4, Eduardo Garzanti5, Giovanni Vezzoli5,

Dan Barfod6 & Ben Kneller7

* [email protected]

1Robertson CGG, UK;

2Lancaster University Environment Centre

3NIGL, British Geological Survey

4BP Egypt, Cairo 5University of Milano‐ Bicocca, Italy

6Scottish Universities Environmental Research Centre, UK

7University of Aberdeen School of Geosciences

Knowledge of the timing of Nile initiation is important to a number of research questions. The timing of the river’s establishment as a catchment of continental proportions can be used to document surface uplift of its Ethiopian upland drainage, with implications for constraining rift tectonics. Yet proposed times of the river’s initiation as a major drainage are currently constrained no more precisely than Eocene to Pleistocene.

We present the first detailed multiproxy provenance study of Oligocene‐Recent Nile delta cone sediments. Using Sr‐Nd bulk data and detrital zircon U‐Pb and Hf‐isotope data, we record detritus from the Ethiopian Continental Flood Basalts (CFBs) in the Nile delta from the start of our studied record (c. 31 Ma), and thereby show that the Nile river was established as a river of continental proportions by Oligocene times. We show that previous petrographic provenance studies which proposed a Pleistocene age for first arrival of Ethiopian CFBs in the Nile delta did not take into account the strong diagenetic influence on the samples.

There are subtle differences between samples of the Oligocene and Pliocene compared to those from the Miocene and Pleistocene, reflecting the changing tectonic and/or climatic environment through time. Nevertheless, the overall stability of our signal throughout the record, and its similarity to the modern Nile signature, indicates no major change in drainage from the time of initiation to present day. Sediments were derived from Phanerozoic sedimentary rocks that blanket North Africa, Arabian‐Nubian Shield volcanic terranes, and Ethiopian CFB’s. We see no significant input from Archaean cratons supplied directly via the White Nile in any of our samples.


49


50

Poster Abstracts


51

Provenance of Carboniferous Deltas – Point sources and Mixed Signals.

Bébhinn Anders1,2, Shane Tyrrell1,2,3, John Murray 1,3, John R. Graham4

*[email protected]

1Earth and Ocean Sciences, School of Natural Sciences, National University of Ireland Galway, University Road, Galway, Ireland. 2Sediment Origins Research Team (SORT), School of Natural Sciences, National University of Ireland Galway, Ireland 3Irish Centre for Research in Applied Geosciences (iCRAG) 4Department of Geology, Trinity College Dublin, College Green, Dublin 2, Ireland

This research aims to better constrain the source to sink process by examining sediment supply,

depositional architecture and the nature and evolution of ancient depositional systems using high‐

resolution sedimentological and provenance analysis. These concepts are important to understand

as they will inform as to the extent to which processes such as shelf mixing and point sourcing affect

the provenance signal. Deltas are ideal to test these ideas as they comprise of a wide range of

depositional environments often showing repetition in facies packages with many processes acting

on the sediment including longshore drift, wave reworking and direct fluvial input. The Mullaghmore

Sandstone Formation (MSF) onshore west of Ireland in the North West Carboniferous Basin (NWCB)

is an ancient fluvial/deltaic sedimentary system deposited during a regional lowstand in the

Carboniferous (mid Visèan) and is an ideal testing site. The MSF comprises cycles of various facies

packages, with outcrops exposed along an 80kmkm stretch of coastline through which the

provenance signal can be investigated. Sampling of these different localities within the basin should

show any spatial variations in the source signal. Results will also provide us with a clearer insight into

the Carboniferous palaeogeography of northwest Ireland.

A near complete lithological section of the MSF has been logged in detail and distinct facies packages

identified. Samples were collected from carefully selected strata and a multi‐proxy provenance

approach was applied using optical microscopy, scanning electron microscopy, major and trace

element whole rock data, U‐Pb zircon and Pb‐in‐K‐feldspar analysis. Current results suggest a

medium‐scale sedimentary supply system, with derivation from multiple sources located further to

the north/ northwest of the NWCB, with sediments deriving mainly from Greenland, NW Scotland

and highs offshore Ireland, with minor input from the Donegal Granite. Channelised facies show a

more unimodal signal compared to shoreface facies which have a very broad, mixed source signal.

Future work will expand the study area and using the same method and techniques to examine the

MSF in its other localities and investigate broader scale variations in the spatial patterns of this

depositional system.


52

Quartz and zircon de-coupling in sandstone: petrology and quartz cathodoluminescence of the German Triassic Buntsandstein Group

Carita Augustsson1*, Michaela Aehnelt2, Thomas Voigt2; Cindy Kunkel3, Marcus Meyer2 and Florian

Schellhorn2

*[email protected]

1Institutt for Energiressurser, Universitetet i Stavanger, 4036 Stavanger, Norway 2Institut für Geowissenschaften, Friedrich‐Schiller‐Universität Jena, Burgweg 11, 07749 Jena,

Germany 3Leibniz‐Institut für Angewandte Geophysik (LIAG), Stilleweg 2, 30655 Hannover, Germany

We illustrate how de‐coupling of quartz and zircon can be used advantageously in provenance

research. Thirty‐eight fine‐grained to coarse‐grained arkose samples of the Early Triassic

intracontinental Buntsandstein Group from the Central European Basin in Germany were analysed

for their petrography and 1200 grains in 23 of these for their detrital quartz cathodoluminescence

characteristics. The samples represent the Eichsfeld‐Altmark Swell and the Hessian and Thuringian

subbasins west and east of the swell, respectively. Lithic fragments are sparse but with more

metamorphic grains in the Hessian Subbasin than further east and a larger content of plutonic grains

in the Thuringian Subbasin. More than 90 % of the detrital quartz from the eastern Thuringian

Subbasin produce medium to bright blue cathodoluminescence colours and corresponding spectra

that are typical for crystallisation in igneous and high‐temperature metamorphic rocks. In the

Hessian Subbasin, the quartz typically luminesces in brown and dark to medium blue, which is typical

for low‐temperature metamorphic origin. Quartz from the Eichsfeld‐Altmark Swell and the western

Thuringian Subbasin are a mixture between the two subbasins. These results indicate different

catchments for the subbasins, possible the Bohemian Massif and the Massif Central, with converging

transport routes on and close to the eastern fringe of the swell. Light mineral‐zircon grain‐size shifts

of 0.7 to 2 units mostly are in accordance with de‐coupled transport of quartz and zircon that was

exaggerated by combined fluvial and aeolian transport, as well as sample preparation‐induced

sorting. We conclude that submerged highs significantly can influence continental sediment

transport. Hence, vast, flat continental areas with submerged morphological highs and a seemingly

straightforward transportation pattern may be more complex than expected. The results also

illustrate that analysis of detritus that has been affected by different dominating transport modes

and further sorting during sampling and preparation can reveal additional source information.


53

Pb isotopic fingerprinting of plagioclase as a sand tracking tool: A validation study

Aoife Blowick*1, Shane Tyrrell1 and Peter Haughton2

*[email protected]

1 Sediment Origins Research Team (SORT), Earth and Ocean Sciences and Irish Centre for Research in Applied Geosciences (iCRAG), National University of Ireland, Galway.

2 Irish Centre for Research in Applied Geosciences (iCRAG), School of Earth Sciences, Science Centre West, University College Dublin.

The Pb isotopic composition of detrital K‐feldspar is a well‐established provenance technique in both

modern and ancient systems. However, source rock fertility bias means mafic source rocks, lacking

K‐feldspar, may be underrepresented by this approach when used in isolation, leading to erroneous

interpretations of palaeodrainage and inaccurate models of source terrane contributions. The Pb

isotopic composition of plagioclase, alongside K‐feldspar, may therefore offer a complimentary yet

improved insight into sedimentary provenance. In particular, plagioclase fingerprinting may hold the

key to unravelling sediment pathways feeding active margin basins.

As a first step we ask (1) does the Pb isotopic composition of plagioclase reflect that of its source

rock? And if so, (2) does the Pb isotopic composition of detrital grains remain unchanged by

weathering, erosion, transport, storage, burial and diagenesis? In order to answer these questions,

the Pb isotopic composition of plagioclase from both felsic and mafic crystalline basement‐arkose

pairs are being analysed. Detailed mapping of isotopic and element patterns using high resolution in

situ LA‐ICPMS techniques will be used to identify any discrete zoning present which could provide a

means of micro‐fingerprinting individual source rocks.

In order to test whether the Pb isotopic composition of detrital grains is retained from source to

sink, the Pb isotopic fingerprint of plagioclase (as well as K‐feldspar) from soil pedons across all

major climates are being analysed. These field examples are complimented by on‐going lab

experiments studying the weathering of feldspar grains using organic acids in order to mimic natural

weathering conditions.

This research is supported in part by a research grant from Science Foundation Ireland (SFI) under

Grant Number 13/RC/2092 and is co‐funded under the European Regional Development Fund. by

PIPCO RSG and its member companies.


54

Provenance of Permian-Triassic metasedimentary rocks in the Antarctic Peninsula and southern Patagonia using U-Pb age, Lu-Hf and O isotopic

compositions in zircon

Paula Castillo1,2*, Mark Fanning1

*paula.castillo@uni‐muenster.de

1 Research School of Earth Sciences, the Australian National University 2 Institut für Geologie und Paläontologie, Westfälische Wilhelms-Universität Münster The Permian–Triassic is a critical period for interpreting and understanding the development of West Antarctica and its connection to southern South America, Patagonia. Permian–Triassic metasedimentary rocks are the host to a major population of Permian igneous zircons1,2, indicating significant Permian magmatism along the southern margin of Gondwana. However, the location and characteristics of the Permian source(s) are still not well known. Combined U‐Pb, O, and Lu‐Hf isotope analyses of detrital zircon grains in Permian–Triassic metasedimentary rocks indicate that the Permian magmatism resulted from the interaction of crust‐ and mantle‐derived sources in an active continental margin. Permian detrital zircons from the Trinity Peninsula Group (TPG) in the Antarctic Peninsula range from crustal signatures in the northern part (δ18O of ~8‰, initial εHf of ~‐6) to mantle‐like values in the south (δ18O of ~5‰, initial εHf of ~+3). Zircons from the northern TPG have isotopic features similar to those from the Patagonian Duque de York Complex. Middle Jurassic metasedimentary rocks in the Antarctic Peninsula also record a ca. 250 Ma igneous source, with stronger crustal signatures (δ18O of 7.5 to 10.8‰ and initial εHf values of ‐3.2 to ‐14.2) and Cambrian inherited cores. They have the same core‐rim structures, U‐Pb ages, Lu‐Hf and O zircon isotopic signatures as recently reported Permian–Triassic granites in Tierra del Fuego, Patagonia3. Other possible source rocks are isolated outcrops in the Eastern and Central domains of the Antarctic Peninsula. Granites from the Eastern Domain have the strongest affinity with Patagonia and the northern TPG, with igneous zircons having initial εHf values ranging from ‐2.8 to ‐21.6, and δ18O from 10.5 to 5.6 ‰. A mid–late Triassic gneiss from the Central Domain contains zircons recording the presence of a mantle‐like Permian protolith with metamorphic zircon overgrowth at ca. 222 Ma. Therefore, the isotopic signature for the Central Domain suggests the presence of a different continental crust, which may be the source for the mantle‐like zircons in the southern TPG. To conclude, our results provide evidence for a Permian subduction‐related magmatic arc, partly located in Patagonia and extending to West Antarctica with a southerly decrease in δ18O. Our data indicate strong similarities between the Eastern Domain of the Antarctic Peninsula and the southern tip of Patagonia, supporting a continuation of both areas, without the need for any great degree of overlap. 1. Hervé, F., Fanning, C.M., & Pankhurst, R.J., Detrital zircon age patterns and provenance of the metamorphic complexes of southern Chile. J. South Am. Earth Sci. 16, 107−123 (2003). 2. Barbeau, D.L., Davis, J.T., Murray, K.E., Valencia, V, Gehrels, G.E., Zahid, K.M., & Gombosi J., Detrital‐zircon geochronology of the metasedimentary rocks of north‐western Graham Land. Antarct. Sci. 22, 65−78 (2010). 3. Castillo, P., Fanning, C.M., Pankhurst, R.J., Hervé, F., & Rapela, C.W., Zircon O‐ and Hf‐isotope constraints on the genesis and tectonic significance of Permian magmatism in Patagonia. J Geol Soc, London. 174, 803‐816 (2017).


55

Examples of provenance studies in tsunami deposits

Pedro J. M. Costa1*

*[email protected]

1Instituto Dom Luiz, Departamento de Geologia, Faculdade de Ciências da Univ. de Lisboa, Portugal

This work briefly summarizes recent developments in the study of tsunami deposits using provenance tools. Grain‐size, micropalaeontological, microtextural, compositional, micromorphological, morphoscopic, geochemical proxies have been successfully applied to the study of Holocene tsunami deposits in Portugal, Scotland, Indonesia and Chile. Most of these studies were able to establish last‐cycle relationships between sediment source and sink (i.e. tsunami deposit). Ongoing work is aiming to extend, as much as possible, the establishment of provenance relationships linking the final tsunami deposits with the original lithological source. Nevertheless, the establishment of tsunami deposit (last‐cycle) sediment source has facilitated more robust interpretations regarding sediment transport, definition of inundation phases, inundation phases and backwash signatures.

One example is (1) characterized grain‐size populations of the AD 1755 tsunami deposit in Salgados and their likely sources. This analysis allowed to exclude nearshore and offshore sediment as a source and define dunes as the major sedimentary contributor of the deposit.

Another example of provenance tools in tsunami deposits is from the 2004 Indonesian tsunami where backwash and inundation phases were differentiated based in the roundness of zircons. Euhedral zircon (similar the original source) was associated with backwash and rounded zircons were associated with inundation phases due to its similarities with zircons observed in present‐day beach (2).

Heavy mineral signatures have also been applied to study the 8200 cal yrs BP Storegga tsunami deposit (3). In this case, it was possible to establish sediment source of the tsunami deposit based in its mineralogical composition and similarities with under lying (Younger Dryas) glacial till (amphiboles and garnets). Furthermore, microtextural work has enabled sedimentologists to use specific imprints on quartz grains surfaces and relate their presence with specific coastal environments. For example, the number of fresh surfaces is clearly associated with beach environments while dissolution dominance is present in deeper nearshore environments. These studies have contributed to the determination of sediment paths and sources of the AD 1755 tsunami deposit in some Algarve locations (4).

Here, we summarize a number of progresses achieved over recent years in the study of tsunami deposits. The usefulness of provenance tools is demonstrated by their contribution to better interpretations and reconstructions of Holocene tsunami events.

This work was supported by PJM Costa FCT Post‐Doctoral Fellowship SFRH/BPD/84165/2012 and also supported by project FCT UID/GEO/50019/2013 – Instituto Dom Luiz.

1. Costa, P.J.M., Andrade, C., Freitas, M.C., Oliveira, M.A., Lopes, V., Dawson, A.G., Moreno, J., Fatela, F., &

Jouanneau, J.M., A tsunami record in the sedimentary archive of the central Algarve coast, Portugal: Characterizing

sediment, reconstructing sources and inundation paths. Holocene. Volume 22, 899‐914, (2012). 2. Costa, P.J.M.,

Andrade, C., Cascalho, J., Dawson, A.G., Freitas, M.C., Paris, R., & Dawson, S., Onshore tsunami sediment transport

mechanisms inferred from heavy mineral assemblages. Holocene. Volume 25, 795‐809, (2015). 3. Cascalho, J., Costa,

P., Dawson, S., Milne, F., & Rocha, A., Heavy mineral assemblages of the Storegga tsunami deposit. Sedimentary

Geology. Volume 334, 21‐33, (2016). 4. Costa, P.J.M., Andrade, C., Dawson, A.G., Mahaney, W.C., Freitas, M.C., Paris,

R., & Taborda, R., Microtextural characteristics of quartz grains transported and deposited by tsunamis and storms.

Sedimentary Geology. Volume 275–276, 55‐69, 2012.


56

The interplay of sandstone petrofacies and porosity and permeability: implications for reliable quality prediction in clastic turbiditic wedges of

the southern Apennines foreland region, Italy

Salvatore Critelli1*, Mario Borrelli1, Gloria Campilongo1, Francesco Muto1, Enza Nicoletti1, Edoardo

Perri1, Francesco Perri1, and Vincenzo Tripodi1

* [email protected]

1Department of Biology, Ecology and Earth Sciences, University of Calabria, 87036 Arcavacata di

Rende

The Southern Apennines preserve deep‐marine clastic wedges that record the main tectonic events

during structural growing over the Adria margin. In fact, the regional tectonic transition from thick‐

skinned Calabrian accretion and deformation (during Late Paleogene‐to‐middle Miocene) to thin‐

skinned Southern Apennines thrusting (since early‐middle Miocene) is recorded by diverse

contrasting petrofacies in uppermost Paleogene and Miocene‐Pliocene sandstones of dominantly

turbiditic deposits. Most of these sandstones reflect in time and space (a) quartzolithic,

quartzofeldspathic and arkosic petrofacies derived from growing and unroofing Calabrian terranes;

(b) quartzose petrofacies mainly indicate provenance from cratonal African margin, during Langhian,

and/or from lowland internal domains before its deformation, during the Cretaceous to Paleogene;

(c) volcaniclastic sandstone petrofacies also testify active volcanism during the Late Paleogene to

early Miocene. These variable compositions imply strong palaeogeographic constraints for the

central‐western Mediterranean, during the Neogene, reflecting provenance relationships from

differentiate source rocks. These include interplays between ophiolitiferous, uplifted continental

shallow to deep crust, volcanic and sedimentary (mostly carbonate) source rocks.

Since the great complexity and variability of the sandstones petrofacies in the southern Apennine

domain, the porosity‐based models on a relatively large and complete data set, have been proven as

effective method for petrophysical parameters prediction. The studied dataset, is mainly

characterized by porosity variations, that follow the principal sandstone detrital modes. The

quatzolithic petrofacies present the lowest porosities values (average value of 4.8 %), whereas moving towards quartzofeldspatic and arkosic petrofacies, porosity increases up to average values of

10 to 15 %. In contrast, the same trend is not present with permeability that, moreover, does not

show any clear correlation with the porosity but shows a wide spectrum of variability (0.5 to 800 mD) for a restrict range of average pore diameter. Porosity variability is directly linked to the

average pore size increasing and the decreasing of the nano‐pores volume, as the good positive

linear correlation between the porosity value and the average pore diameter and the negative

correlation between nano‐pores volume and porosity. Moreover, the pore systems of most of the

studied Units are mainly characterized by meso‐ to micro‐pores, and less by macro‐ and nano‐pores.

Consequently, the quantification of regional detrital modes linked to the characterization of the

principal petrophysical parameters can represents a useful method to achieve a reliable quality

prediction in clastic turbiditic wedges of foreland settings.


57

A suggested standard schema for use in organising and reporting sediment provenance datasets

Lorin Davies1*, Sam Fielding1, Ian Millar2, and Laura Fielding1

* [email protected]

1GeoConsulting, CGG, Llandudno, North Wales, UK 2British Geological Survey, Keyworth, U.K.

We propose a standardised schema for recording and reporting of data for U‐Pb geochronology, Lu‐

Hf zircon geochemistry, petrographic point count data, Sm‐Nd and Rb‐Sr isotope geochemistry for

use in sediment provenance studies. The schema has been derived in order to provide the most

efficient structure possible and to retain all necessary fields for population of data acquired by

multiple techniques; the structure builds upon previous work1, 2, and adding functionality necessary

for manipulating multi‐disciplinary datasets. A template is presented in two formats: 1 A database

schema suitable for on‐premise and cloud‐based database solutions; and 2. A flat spreadsheet ideal

for reporting data in scientific publications. Some standard ‘queries’ are provided for fast integration

of data into packages such as detzr3 and provenance4 packages. Recommendations for best practices

are also presented for discussion, with a view to arriving at a collaborative resource for members of

industry and academia.

Robertson CGG have created a global sediment provenance database harvested from academic

literature worldwide. Over the course of this project a significant volume of data was discarded due

to insufficient data, poor quality control, and/or ambiguous referencing and attribution of data. The

aim of this contribution is to feedback to the scientific community lessons learnt and help to move

towards a set of standards to help sediment provenance specialists, particularly early‐career

scientists working with these data types for the first time; and to invite constructive criticism,

collaboration and improvements to the schema.

1. Horstwood, M., Košler, J., Gehrels, G. Community‐Derived Standards for LA‐ICP‐MS U‐(Th‐) Pb

Geochronology–Uncertainty Propagation, Age Interpretation and Data Reporting. Geostand Geoanal Res. at

<http://onlinelibrary.wiley.com/doi/10.1111/j.1751‐908X.2016.00379.x/full> (2016).

2. Bowring, J.F., McLean, N.M., Bowring, S.A. Engineering cyber infrastructure for U‐Pb geochronology: Tripoli

and U‐Pb_Redux. Geochem Geophys Geosyst. 12 (6), Q0AA19 (2011).

3. Kristoffersen, M. detzrcr. at <https://github.com/magnuskristoffersen/detzrcr>. Github. (2017).

4. Vermeesch, P., Resentini, A., Garzanti, E. An R package for statistical provenance analysis. Sediment Geol.

336 (Supplement C), 14–25 (2016).


58

Detrital record of the denudation of volcanic islands in sub-tropical climate

Pedro A. Dinis1* and Marina C. Pinto2

*[email protected]

1 MARE‐Marine and Environmental Sciences Center; Department of Earth Sciences, University of

Coimbra, Portugal 2 Geobiotec Research Centre; Department of Geosciences, University of Aveiro, Aveiro, Portugal

The composition of volcanic islands is largely determined by a mixture in diverse proportions of

components associated with the depleted mantle, enriched mantle, recycled crust, among others.

Given the composition and texture of the rocks found in volcanic islands, the weathering and

subsequent erosional processes is distinct from what is observed in tectonic settings with higher

contribution of geological material linked to the continental crust. The compositionally homogenous

southern chain of the Cape Verde archipelago is an excellent region to investigate the denudation

processes under low weathering intensities. In the present work the geochemistry of bedload river

and beach sediments collected in the “old” Maio Island (shield building stage older than 5 Ma;

basement complex older than 20 Ma; with diverse sedimentary units related to previous denudation

phases), and the “young” Fogo Island (shield building stage still running; basement complex younger

than 5 Ma; virtually no sedimentary units related to previous denudation phases) are used to

examine the denudation record. When compared to the volcanic rocks of the islands, bedload

sediments are frequently characterized by moderate depletion in Al2O3, which tends to be more

intense in beach than in river deposits and in “old” than in “young” islands. This depletion is

attributed to the low stability of volcanic glass under exogenous environments, being a major

limitation to the application of the indices used to understand compositional changes during

weathering in these tectonic and climatic contexts. Alternative formulations inspired in the α

mobility indices1,2 were tested. An index that, instead of the Upper Continental Crust, uses the

composition of the volcanic rocks of Cape Verde’s southern chain, and Fe as the non‐mobile

reference produces a reliable ranking of element mobility that does not seems to be affected by

source rock composition and sorting processes. In addition, it was able to discriminate sediments

sourced by volcanic rocks of different age and variable contribution of recycled sedimentary

material.

1. Gaillardet, J., Dupré, B. & Allègre, C.J.. Geochemistry of large river suspended sediments: silicate weathering

or recycling tracer? Geochimica et Cosmochimica Acta, 63 (1999). 2. Garzanti, E., Padoan, M., Setti, M., Peruta,

L., Najman, Y. & Villa, I.M. Weathering geochemistry and Sr‐Nd isotope fingerprints of equatorial upper Nile

and Congo muds. Geochemistry, Geophysics, Geosystems, 14 (2013).


59

A sedimentary provenance study of modern river sands from northern Fennoscandia and its insight on identifying mineral fertility, bias and the

source of Mesozoic successions deposited on the Barents Shelf

Michael J. Flowerdew1*, Edward J. Fleming1, David M. Chew2, Andrew C. Morton1,3, Magdalena

Biszczuk1, Dirk Frei4 and J. Stephen Daly5,6

*[email protected]

1CASP, West Building, Madingley Rise, Madingley Road, Cambridge, CB3 0UD, UK

2Department of Geology, Trinity College Dublin, Dublin 2, Ireland

3HM Research Associates, Musselwick Road, St Ishmaels, SA62 3TJ, UK

4Dept. of Earth Sciences, Uni. of the Western Cape, Private Bag X17, Bellville 7530, South Africa

5Department of Geological Sciences, University College Dublin, Belfield, Dublin 4, Ireland

6Irish Centre for Research in Applied Geosciences (icrag‐centre.org)

A series of sedimentary provenance techniques were applied to 20 modern sand samples collected

from twelve major river catchments in northern Fennoscandia. This was carried out in order to

evaluate the extent to which Mesozoic successions deposited on the southwest Barents Shelf were

sourced from northern Fennoscandia.

One of the most distinctive provenance signatures in northern Fennoscandia occurs in samples from

the Tana River, which crosses the Lapland Granulite Belt (LGB). Downstream of exposures of the

LGB, modern sands are dominated by rutile with c. 1.9 Ga U‐Pb ages and a chemistry indicating

crystallization at c. 850 °C from a pelitic protolith. A detrital rutile signature similar to that in the

Tana River is replicated in the Late Triassic – Early Jurassic Realgrunnen Subgroup deposited in the

vicinity of the Nordkapp Basin, and indicates a common origin from the LGB. The Realgrunnen

Subgroup deposited in the Hammerfest Basin has strikingly different provenance pattern. Here,

rutiles have mostly c. 430‐515 Ma ages and crystallised at c. 650 °C from a pelitic protolith. The

similarity of this pattern to rutile data from the modern Målselva River indicates a source from

Caledonian allochthons affected by Palaeozoic amphibolite‐facies metamorphism.

Models depicting rejuvenation of a Fennoscandian sedimentary source region and Late Triassic

drainage reorganisation are supported by these data. The rutile technique provides one of the

clearest mechanisms for tracing the dispersal of Fennoscandian‐derived sediment across the Barents

Shelf.

Despite these contrasting rutile signatures, the Nordkapp Basin and Hammerfest Basin samples

yielded remarkably similar zircon U‐Pb age patterns. Their zircon age spectra are dominated by 1.0

Ga ‐ 1.7 Ga grains. This age range does not correspond with widespread igneous or metamorphic

events in northern Fennoscandia and so these zircons were probably recycled from sedimentary

units.

A statistical assessment of the multi‐proxy modern sand dataset, through INSCAL and Procrustes

analysis, helps to identify the Barents Sea Group as a source of recycled detrital zircon and hence can

account for the mismatch of zircon and rutile patterns in some of the Mesozoic offshore samples. It

also shows how readily sedimentary reworking, uneven erosion and fertility can affect and bias the

various sedimentary provenance signals.


60

Sand composition as a tool for liquefaction phenomena assessment

Daniela Fontana1* and Stefano Lugli1

*[email protected]

1 Dept. of Chemical and Geological Sciences, University of Modena and Reggio Emilia, Italy

The petrographic composition of sands is a useful tool for the assessment of the complex phenomena related to co‐seismic liquefaction, such as sand blows, dykes, sand volcanoes and may also help in identifying ancient earthquake effects.

Fluvial sand composition studies have a particular significance in the late Pleistocene–Holocene Po

Plain, where distinct compositional fields characterize modern sands from different streams, as well

as older sediments1. Several key petrographic components provide diagnostic features to distinguish

sand bodies buried beneath the floodplain.

The composition of sands ejected during the 2012 Mw 6.1 Emilia earthquake from several sites in

the Emilia plain (Modena and Ferrara provinces)2 has been compared with buried sands from cores

and trenches at different depths (down to 50 m) in order to identify the source layers which

originated the liquefaction phenomena.

The sands from the cores show a clear trend from lithoarenitic to quartz‐feldspar‐rich compositions.

The sands at shallow depth (down to 7 m) are the most lithoarenitic, with sedimentary fine‐grained

rock fragments (limestone, shale and siltstone) as the dominant lithic type. Lithic fragments derive

mostly from the erosion of sedimentary terrigenous and carbonate successions of Apenninic affinity

referable to different fluvial systems (Secchia and Reno rivers). These shallow sands are well

distinguishable from the deeper sands (at depth > 7 m), which show compositions slightly enriched

in quartz and feldspars and impoverished in lithic fragments suggesting affinity with the Po river

sands or older sands deposited during the last Glacial Maximum.

In all examined sites the composition of the ejected sands largely overlap that of the shallow late

Holocene Apenninic sands, indicating that liquefaction processes affected mainly sand layers at

depth of 6‐7.5 m.

The study shows that composition of sands is crucial for a better understanding of earthquake‐

induced liquefaction mechanisms, in particular to identify the source layer of the sand blows and,

more generally, for the recognition of critical layers, which may be prone to hazardous sand

liquefaction phenomena.

1. Lugli S., Marchetti Dori S., Fontana D. Alluvial sand composition as a tool to unravel the Late Quaternary

sedimentation of the Modena Plain, northern Italy. Geological Soc.of America Sp Paper, 420, 57‐72 (2007). 2.

Fontana, D., Lugli, S., Marchetti Dori, S., Caputo, R., and Stefani, M. Sedimentology and composition of sands

injected during the seismic crisis of May 2012 (Emilia, Italy): clues for source layer identification and

liquefaction regime. Sedimentary Geology, 325, 158‐167 (2015).


61

Mineralogy and Genesis of Manganese Ores of Tunisia:

Preliminary Results

Hechmi Garnit 1*, Donatella Barca 2, Salah Bouhlel 1 and Mariano Davoli 2

*[email protected]

1Mineral Resources Team, LRM2E, Geology Department, Faculty of Sciences of Tunis, University of

Tunis El Manar, 2092 Tunis, Tunisia 2 DiBEST (Department of Biology, Ecology and Earth Sciences) University of Calabria, Italy

Few meso‐scale Mn‐ores are documented in Tunisia. These minerals are hosted by deposits of

various age, size, grade and origin(s) and they occur in close association with Fe‐ores. The

mineralogy, geochemistry and, in most cases, the origin of them are fairly well known. The Tamra

deposits (Nappe zone, northern Tunisia) correspond to a Mio‐Pliocene polystage complex Fe‐Mn

mineralized system. The Fe–Mn mineralization mostly occurs as lenses and stratiform layers, which

are restricted to the Tamra marginal basin. The recognized ore minerals are hematite, goethite,

limonite, kaolinite, hollandite, coronodite, romanechite, psilomelane and striontiomelane. Mn‐ores

occur as porosity filling in the ferruginous matrix, impregnation, concretions and boxworks. The Mn‐

ores in Jebel Aziza (southern Tunisian Atlas, central Tunisia) correspond to karstic filling and

stockwork type in late Cenomanian‐Turonian dolomite. In the Jebel Ank (southern Tunisian Atlas,

central Tunisia), the Mn‐ores occur as centimeter irregular nodules in late Eocene marls.

In this research, petrographic, mineralogical and geochemical studies have been performed in order

to characterize and discuss the possible origin(s) of this important Mn‐mineralization in Tunisia. We

used transmitted and reflected optical microscopy and scanning electron microscopy (SEM‐EDS) for

petrographic section and an electron microprobe (EMPA), in order to identify the Mn‐oxides

composing the mineralization. LA‐ICP‐MS has been used, instead, to determine trace and rare earth

element (REE) concentrations to discuss their genesis.

The Mn‐minerals are mixtures of Mn‐Ba‐Sr and Mn‐Zn‐Fe oxides in Tamra, Mn‐Ba oxides in Jebel

Aziza and Mn‐K oxide in Jebel Ank.

The Mn‐ore mineralogy, trace elements content and REE patterns support hydrogenous origin for

Jebel Ank, a complex hydrothermal‐supergene origins(s) for Tamra and hydrothermal ‐ diagenetic

origin(s) for Jebel Aziza.


62

One small terrane-boundary basin – five different sources of sediment

Peter Haughton1*

*[email protected]

.1iCRAG & UCD School of Earth Sciences, University College Dublin, Dublin, Ireland

The sediment filling basins associated with major strike‐slip faults can sample diverse source areas

on account of across‐basin changes in the nature of the crust, lateral sliding of terranes past the

basin and a tendency for large river systems to be conducted along the topographic depressions

generated by mechanically weak fault rocks. In active margin settings, there is the added

complication of episodic volcanic input following pyroclastic eruptions. Late Silurian basins

developed along the southern margin of the Grampian terrane in Scotland and Ireland record

sediment generation and dispersal during the Caledonian Orogeny and an associated magmatic

flare‐up. The Crawton Basin in the north‐east Midland Valley of Scotland was a small (ca 15‐20 km

wide) late Silurian basin dominated by gravel‐bed river systems that drained both across the

Highland Boundary and from a hinterland within the Midland Valley. Facies and provenance analysis

demonstrate complex sediment sourcing and mixing with large antecedent rivers entering from the

north carrying different mixtures of recycled and first‐cycle components from at least two entry

points, and first‐cycle consequent rivers delivering compositionally very different sediment from the

south. In addition, polymict volcaniclastic sediments from the north, and monomict andesitic

breccias and tuffs from the south episodically blanketed rivers that dominantly transported non‐

volcanic detritus. Given the small size of the basin, the large scale of the gravel bars and the

dominance of gravel over sand, it is likely the rivers both entered and exited the basin with basin

subsidence acting to preferentially extract and preserve only the coarsest cobble and boulder‐grade

bed load. The provenance of the various conglomerates is key to: (1) limiting the amount of post‐late

Silurian lateral displacement along the Highland Boundary; (2) demonstrating a significant crustal

boundary beneath the basin and by implication on the Highland Boundary – granite clasts derived

from either margin of the basin indicate the source plutons have interacted with very different crust,

and (3) reconstructing the nature of the Midland Valley crust as this is now largely concealed by

Devonian and younger rocks. Common Pb isotope data for feldspars determined using both TIMS

and LA‐ICPMS help tie clasts to currently exposed granite bodies in the NE Grampian Highlands,

ruling out significant supply from the Scandian, suggesting the basin may represent the last

increment of any transcurrent displacement on the Highland Boundary, and confirming the current

erosion level in the NE Highlands is not that different to that during the late Silurian.


63

Provenance and tectonic setting of the Slovenj Gradec Basin sedimentary succession (Western part of the Pannonian Basin system)

Kristina Ivančič*1, Mirka Trajanova1, Dragomir Skaberne1, and Andrej Šmuc2

*kristina.ivancic@geo‐zs.si

1Geological survey of Slovenia, Dimičeva ulica, Ljubljana, Slovenia 2Department of Geology, University of Ljubljana, Aškerčeva ulica, Ljubljana, Slovenia

Slovenj Gradec Basin represents one of the marginal parts of the Pannonian Basin system.

Sedimentary origin and tectonic setting was investigated by combination of field work, comprising

measurements of textural parameters, petrographic, and geochemical analyses. Special stress was

laid to imbrication dips, and directions of the conglomerate beds wedding‐out. Main direction of the

sediment input was from the areas, which now occur to the north, west, southwest, and south.

Particular pebbles (tonalite, granite, and oncoidal limestone) in the conglomerate gave unequivocal

indications of their origin. Composition of sandstone indicates that lithic grains of metamorphic and

carbonate rocks, and quartz prevail over other mineral grains (phyllosilicates, feldspars, and

accessory minerals), lithic grains of igneous rocks, and alocheme components. Specific lithic grains

belonging to serpentinite, altered basalt, and bioclasts of alveolinid‐numulitid limestone in

carbonate grain confine the provenance area to the west, and north‐west. Provenance was defined

also by discriminant function after Roser and Korsch (1988). The samples plot into the field of

quartzose sedimentary provenance. The analyses indicate the same main direction of the sediment

delivery into the basin as the pebbles, and indicate subordinate input from the southwest, and

south. Accordingly it is concluded that the main origin of the sediments was from the Eastern Alps,

and subordinately from the Eisenkappel igneous belt, and Southern Alps. Tectonic settings were

determined by Dickinson diagram (Dickinson and Suczek, 1979), multi‐dimensional diagram after

Verma and Armstrong‐Altrin (2013), discriminant plot after Roser and Korsch (1988), and

discriminant function after Verma and Armstrong‐Altrin (2016). The results are not representing a

unified tectonic setting. Dickinson diagram indicates the sedimentary supply form the recycled

orogen. Multi‐dimensional diagram indicate that the sediments originate from collision zone. The

result of the discriminant plot indicates the origin of the sediments from the oceanic island arc,

which is not suitable in our case. The studied samples plot into the passive margin field, using the

discriminant function. The results of the tectonic setting show that the sediments from the SGB were

subjected to two different tectonic events (Ivančič et al., 2017). The first two diagrams reflect

tectonic setting of the source area (Alpine collision), and the last tectonic setting of the deposition

area appurtenant to the evolution of the Pannonian‐Carpathian region.

1. Dickinson,W.R., & Suczek, C.A., Plate tectonic and sandstone compositions. American Association of

Petroleum Geologists Bulletin. 63, (1979). 2. Ivančič, K., Trajanova, M., Skaberne, D., & Šmuc, A., Provenance of

the Miocene Slovenj Gradec Basin sedimentary fill, Western Central Paratethys. Sedimentary Geology. In

press, (2017). 3. Roser, B.P., & Korsch, R.J., Provenance signatures of sandstone‐mudstonen suites determined

using discriminant function of major‐element data. Chemical Geology. 67, (1988). 4. Verma, S.P., & Armstrong‐

Altrin, J.S, New multi‐dimensional diagrams for tectonic discrimination of siliciclastic sediments and their

application to Precambrian basins. Chemical Geology. 355, (2013). 5. Verma, S.P., & Armstrong‐Altrin, J.S.,

Geochemical discrimination of siliciclastic sediments from active and passive margin settings. Sedimentary

Geology. 332, (2016).


64

Sediments of two Gondwana glaciations in Ethiopia: Provenance information from heavy minerals and detrital zircon ages

Anna Lewin1*, Guido Meinhold2,3, Matthias Hinderer1, Enkurie L. Dawit4, and Robert Bussert5

*[email protected]‐darmstadt.de

1Institut für Angewandte Geowissenschaften, Fachgebiet Angewandte Sedimentologie, Technische

Universität Darmstadt, Schnittspahnstraße 9, 64287 Darmstadt, Germany 2Abteilung Sedimentologie/Umweltgeologie, Geowissenschaftliches Zentrum Göttingen, Universität

Göttingen, Goldschmidtstraße 3, 37077 Göttingen, Germany 3School of Geography, Geology and the Environment, Keele University, Keele, Staffordshire, ST5 5BG,

UK 4Department of Geology, University of Gondar, P.O. Box 196, Gondar, Ethiopia 5Institut für Angewandte Geowissenschaften, Fachgebiet Explorationsgeologie, Technische

Universität Berlin, Ackerstraße 76, 13355 Berlin, Germany

The East African Orogen, which formed during the amalgamation of Gondwana, shed huge amounts

of sediment towards the continental margins during the Palaeozoic. In Ethiopia, Palaeozoic

sedimentary successions can be assigned to the two major Gondwana glaciations in the Late

Ordovician and the Carboniferous–Permian. The distribution of ice sheets and continent‐wide glacier

dynamics during these glacial periods are still under discussion. The Arabian‐Nubian Shield – the

northernmost part of the East African Orogen – is a probable local source region for the sediments.

However, far transport from central Gondwana (e.g., East Africa) is also possible. Ethiopia is a key

region between potential distant sediment sources and the northern margin of Gondwana.

To assess differences in provenance, transport and weathering conditions, we compare sediments of

both glaciations regarding their heavy mineral assemblage, rutile and garnet chemistry, and detrital

zircon ages.

For the Late Ordovician sandstones, the enrichment of ultra‐stable heavy minerals indicates intense

weathering and reworking prior to deposition, yet a facies dependency suggests a certain degree of

post‐depositional dissolution. Rutile is omnipresent and can be assigned to mainly amphibolite facies

meta‐felsic source rocks. Only little garnet is present. The Carboniferous–Permian sandstones are

more variable regarding their heavy mineral assemblage. The prevalence of garnet and apatite

points to extremely slight influence of acidic weathering. Garnet chemistry reveals both igneous and

metamorphic sources. Detrital zircons of both formations are mainly Pan‐African in age. However,

the Late Ordovician sandstones further contain prominent amounts of Tonian–Stenian (c. 1 Ga) and

Palaeoproterozoic zircons. We assume an association with the Gondwana super‐fan system. Besides

Pan‐African ages, the Carboniferous–Permian sandstones are characterised by c. 800 Ma old zircons,

which may be derived from a local source.


65

An Empirical Method to Predict Sediment Grain Size from Inorganic Geochemical Measurements

Dawei Liu1*, Sebastien Bertrand1, and Gert Jan Weltje2

*[email protected]

1Renard Centre of Marine Geology, Ghent University, Krijgslaan 281 S8, 9000 Ghent, Belgium 2Department of Earth and Environmental Sciences, KU Leuven, Celestijnenlaan 200e, 3001 Leuven,

Belgium

Grain size is one of the most fundamental properties of sediments. It is frequently used in

paleoclimate, paleoceanographic and paleoenvironmental reconstructions as a proxy for river

discharge, current and wind strength, and to identify mass flow deposits in sediment cores.

Measuring grain‐size, however, is time‐consuming and destructive. Given the strong influence of

grain size on sediment inorganic geochemistry, single element variations measured by e.g. XRF core

scanning are increasingly used to estimate grain‐size variations at high resolution in sediment cores.

This approach is however limited to a narrow grain‐size range since single elements only

monotonically relate to grain‐size over a narrow size range. In this paper, we present a simple, code‐

free, multi‐element technique based on Partial Least Square regression to predict sediment mean

grain size from inorganic geochemical data over the range of sizes commonly encountered in nature

(from clay to coarse sand). The method was first tested and validated using river sediment samples

separated in 11 grain‐size fractions and it was later successfully applied to two sediment cores from

the Chilean fjords, with mean grain sizes ranging from 16–31 and 7–180 µm. Our method only

requires measuring grain‐size on a limited number of carefully selected calibration samples, and it is

able to predict mean grain‐size at XRF core scanner resolution. Provided sediment provenance,

weathering, and diagenesis are relatively stable through time, this technique is applicable to any lake

or marine sediment core, and we anticipate that it will result in a significant increase in the

resolution of sediment proxy records of climate and environmental change.


66

Spatial and temporal variation in fluvial sediment supply to the Cretaceous Western Interior Seaway of North America

Sinéad Lyster1*, Alexander Whittaker1, Peter Allison1 and Sarah‐Jane Kelland2

*[email protected]

1Department of Earth Science and Engineering, Imperial College London, London, SW7 2AZ, United

Kingdom. 2Getech Group plc, Leeds, LS8 2LJ, United Kingdom.

The flux of sediment to the ocean is governed by tectonic and climatic boundary conditions, which

influence source area denudation rates and spatio‐temporal patterns in sediment routing.

Depositional stratigraphy therefore represents the time‐integrated product of erosional fluxes from

terrestrial catchments via palaeo‐sediment routing systems. Understanding how, when and where

sediment was delivered from the continents to oceans remains a prominent research challenge in

the Earth sciences. However, to date, palaeo‐sediment routing system analysis has been limited by

the incomplete record of terrestrial catchments.

Here we use a numerical modelling approach (BQART) to reconstruct erosion and sediment supply in

deep time for the North American continent. Our approach exploits new palaeogeographies of the

globe to predict the geometries of large continental palaeocatchments, as well as palaeoclimate

data from coupled atmosphere–ocean general circulation models. We then use the BQART sediment

flux model to produce first‐order estimates of fluvially‐derived suspended sediment flux to the

Cretaceous Western Interior Seaway (WIS) of North America.

Our analyses reconstruct over 1400 North American palaeocatchments with areas greater than

500 km2. Of these, up to 700 catchments deliver sediment to the WIS. Preliminary results suggest

continental‐average denudation rates of 0.1 mm/yr and sediment yields of ~150 t/km2/yr, which are

consistent with modern continents. Latitudinal trends in erosion and sediment supply to the WIS are

reconstructed for Cretaceous time slices, and the relative contributions of the western and eastern

margins of the WIS to total sediment input are also predicted. We ground truth our estimates

against published geologic constraints and find that BQART estimates of suspended sediment flux to

the WIS are the same order of magnitude as predictions derived from previous mass‐balance and

fulcrum approaches, and most lie within a factor of two.

Our results demonstrate the suitability of this approach for investigating palaeo‐sediment routing in

space and time, especially where physical records are absent, and highlight potential use for

reconstructing the global response of sediment supply to long‐term tectonic and climatic events in

the geologic past.


67

Sediment hunting: Provenance of the Upper Jurassic NCSB and what we know

Odhran McCarthy1*, Pat Meere1 and Dave Chew3

*Odhran.mccarthy@icrag‐centre.org

1iCRAG, School of Biology, Earth & Environmental Sciences, University College Cork

2iCRAG, Department of Geology, School of Natural Sciences, Trinity College Dublin

Sedimentary basins hold an economic and historic importance. The North Celtic Sea Basin (NCSB),

comprised of Mesozoic sediments plays host to a number of potential economically viable reservoir

sands. Upper Jurassic sediments in the NCSB are composed of marginal marine to terrestrial

sediments with localised variability. They comprise reservoir sands with capacity to host

hydrocarbons while recording changes in paleoenvironment, revealing new information about

regional geology and potential provenance changes. Furthering previous research, this project aims

to identify changes in provenance at a regional and localised scale. A multidisciplinary approach

including quantitative sedimentary petrology, detrital geochronology, grain shape and heavy mineral

analysis (RAMAN & QEMSCAN) are utilised to elucidate the provenance and routing of sediments.

Previous work on the Munster basin and NCSB has identified a number of Irish source regions, but

has also suggested that sediment recycling from the Munster basin may play a key role in the NCSB’s

infill. New heavy mineral and petrographic data indicate the provenance of these sediments while

characterising diagenesis and composition. Zircon and apatite isotope data and tourmaline trace

element data will be used to further discriminate source regions following these preliminary results.

Utilising published sedimentary data and supplementing it with new data, a reconstruction of the

paleogeography of Ireland and the UK during the Mesozoic is presented.

Fairey, B. J., Kerrison, A., Meere, P. A., Mulchrone, K. F., Hofmann, M., Gärtner, A., Sonntag, B.‐L., Linnemann, U., Kuiper, K. F., and Ennis, M., 2018, The provenance of the Devonian Old Red Sandstone of the Dingle Peninsula, SW Ireland; the earliest record of Laurentian and peri‐Gondwanan sediment mixing in Ireland. Journal of the Geological Society, p. jgs2017‐2099.

Morton, A., Knox, R., and Frei, D., 2016, Heavy mineral and zircon age constraints on provenance of the

Sherwood Sandstone Group (Triassic) in the eastern Wessex Basin, UK: Proceedings of the Geologists'

Association, v. 127, no. 4, p. 514‐526.

Tyrrell, S., Haughton, P. D., Souders, A. K., Daly, J. S., and Shannon, P. M., 2012, Large‐scale, linked drainage systems in the NW European Triassic: insights from the Pb isotopic composition of detrital K‐feldspar: Journal of the Geological Society, v. 169, no. 3, p. 279‐295.

Waldron, J. W. F., Schofield, D. I., Dufrane, S. A., Floyd, J. D., Crowley, Q. G., Simonetti, A., Dokken, R. J., and

Pothier, H. D., 2014, Ganderia–Laurentia collision in the Caledonides of Great Britain and Ireland: Journal of the Geological Society, v. 171, no. 4, p. 555‐569.


68

The lithostratigraphy of the Bradfield Southend Boreholes, Berkshire UK: An examination of the Late Cretaceous – Palaeogene boundary in the

western London Basin.

Ian Mounteney1*, Peter Hopson1, Seb Gurrola2, Rosemary Jenkins3, Ian Wilkinson1, Mark Woods1

and Steve Thorpe1

*[email protected]

1 British Geological Survey, Environmental Science Centre, Keyworth, Nottinghamshire NG12 5GG,

United Kingdom.

2 21 Burvale Court, 13 Rickmansworth Road, Watford, Hertfordshire, WD18 0JQ

3 Birmingham University

Detailed heavy mineral interpretations of the Bradfield Southend boreholes provide a rare detailed

glimpse into the provenance of the Thames, Lambeth and Chalk Group successions in the western

part of the London Basin. Heavy mineral analysis, together with calcareous microfossil and

palynological studies of the Palaeogene succession confirm the lithostratigraphical division of these

groups. These studies further place the deposits encountered into the regional palaeogeography

related to the early development of the North Sea Basin and the presence of or proximity to a

surrounding terrestrial environment.

The investigations into this early Palaeogene succession confirms the presence of the Ockendon

Member (informal A) and Aveley Member (informal B) units of the London Clay Formation, a thin

representative attributed to the Harwich Formation and a Lambeth Group sequence including thick

Reading‐type clays, a poorly preserved ‘Reading Sand’ unit and representatives of the Upnor

Formation including potentially reworked Thanet Formation material. Changes in heavy mineral

assemblages and their geochemistry help to reflect the various depositional environments which

occur throughout the Palaeogene. Two distinct periods of sediment hiatus have been identified. The

first occurs during the Eocene and the second, previously determined as the Mid Lambeth Hiatus

(MLH), during the Palaeocene. The MLH represents an unconformity during which a shift in sediment

source occurs. The Mid Eocene Hiatus (MEH) overlaps the boundary of the Ockendon and Aveley

Members of the London Clay Formation and represents a shift to a lagoonal environment.


69

Geochemical evidence for large-scale drainage reorganization in Northwest Africa during the Cretaceous

Yannick Mourlot1,2, Martin Roddaz1*, Guillaume Dera1, Gérôme Calvès1, Jung‐Hyun Kim3, Anne‐Claire Chaboureau4, Stéphanie Mounic1 and François Raisson2

*[email protected]

1Géosciences‐Environnement Toulouse, Université de Toulouse; UPS (SVT‐OMP); CNRS; IRD; 14 Avenue Édouard Belin, F‐31400 Toulouse, France

2 Total E&P, CSTJF Avenue Larribau, F‐64018, Pau Cedex, France

3 Korea Polar Research Institute (KOPRI), 26 Songdomirae‐ro, Yeonsu‐gu, Incheon 21990, South Korea

4 CVA Engineering 9/11, allée de l'Arche, Tour Egée, 92671 Courbevoie, La Défense, France

West African drainage reorganization during Cretaceous opening of the Atlantic Ocean is deciphered here from geochemical provenance studies of Central Atlantic sediments. Changes in the geochemical signature of marine sediments are reflected in major and trace element concentrations and Strontium‐Neodymium radiogenic isotopic compositions of Cretaceous sedimentary rocks from eight Deep Sea Drilling Project (DSDP) Sites and one exploration well. Homogeneous major and trace element compositions over time indicate sources with average upper (continental) crust signatures. However, detailed information on the ages of these sources is revealed by Neodymium isotopes (expressed as εNd). The εNd(0) values from the DSDP Sites show a three‐step decrease during the Late Cretaceous: 1) the Albian−Middle Cenomanian εNd(0) values are heterogeneous (‐5.5 to ‐14.9) reflecting the existence of at least three subdrainage basins with distinct sedimentary sources (Hercynian/Paleozoic, Precambrian and mixed Precambrian/Paleozoic); 2) during the Late Cenomanian−Turonian interval, εNd(0) values become homogeneous in the deep‐water basin (‐10.3 to ‐12.4), showing a negative shift of 2 epsilon units interpreted as an increasing contribution of Precambrian inputs; 3) this negative shift continues in the Campanian−Maastrich an (εNd(0) = ‐15), indicating that Precambrian sources became dominant. These provenance changes are hypothesized to be related to the opening of the South and Equatorial Atlantic Ocean, coincident with tectonic uplift of the continental margin triggered by Africa−Europe convergence. Finally, the difference between ε

Nd(0)values of Cretaceous sediments from the Senegal continental shelf and from the deep‐

water basins suggests that ocean currents prevented detrital material from the Mauritanides reaching deep‐water areas.


70

Sedimentary provenance studies in Brazil

Daniel Rodrigues do Nascimento Jr.1*, Pâmella Moura2

*[email protected]

1Departamento de Geologia, Universidade Federal do Ceará, Fortaleza (CE), Brazil. 2Geology Graduate Program, Universidade Federal do Ceará, Fortaleza (CE), Brazil.

Sedimentary provenance is among the basic tasks of sedimentologists, since the pioneer studies on

petrological provinces1 until the nowadays source‐to‐sink approach2. This work aims to present a

state‐of‐art of the research on sedimentary provenance in Brazil. In order to do this, an indexed

publications database was extracted from the ISI’s Web of Science Gateway

(www.isiknowledge.com) using the keywords SEDIMENTARY and PROVENANCE within a global and

country scopes3. All data were obtained in May 2018 and compiled in spreadsheets containing

information about the scientific‐related areas, involved countries, type of publication, year, citations

and h‐index.

The results shown 152 Brazilian publication records since 1994, 96% of these in articles. There was a

relatively strong rising in publications since 2010, starting from an average of five until reach 30

publications per year. Historically, Brazil leads the Latin American in number of contributions (~35%),

and globally occupies the 10th position (~4%). The main knowledge areas signed for the contributions

were Geology (88%) and Geochemistry (7%). Individually, the major partnerships in the productions

came from institutions in Australia (~19%) and United States (~12%); in set, European countries

together represent about 38%. The mean of citations was 21 per publication with a h‐index of 23.

Geographically, there is a lot of Brazilian works developed abroad (~24%), mainly in Argentina and

Colombia. Inside Brazil, Minas Gerais State was the most frequent case study for geographically‐

dependent contributions (~11%); other studies (wider than one Brazilian state of federation,

involving two or more countries, or even geographically‐independent contributions) sum 19

occurrences (~13%).

Our qualitative overview indicates the majority of studies are still highlighting ancient terrains in

Fold Belts and cratonic areas. Paradoxically, few sedimentary provenance studies in Brazil are

focused in non‐metamorphised sedimentary rocks and recent (Quaternary) deposits, therefore

causing an important knowledge gap waiting for more contributions. Our findings also claim for a

need of more studies in remote areas like North Brazil (Amazonia).

1. Pettijohn, F.J., in Sedimentary Rocks (ed. Pettijohn, F.J.) 483‐503, Harper & Row, 1975.

2. Allen, P.A. & Allen, J.R., in Basin Analysis – Principles and Applications (eds. Allen, P.A., & Allen, J.R.) 221‐245,

Blackwell, 2005.

3. Wojciechowski, J., Ceschin, F., Pereto, S.C.A.S., Ribas, L.G.S., Bezerra, L.A.V., Dittrich, J., Siqueira, T., & Padial,

A.A., Latin American scientific contribution to ecology. Annals of the Brazilian Academy of Sciences. V.89, n.4,

2017.


71

Heavy mineral variations in deltaic sandstones: towards a better understanding of pre-depositional sediment history?

Martin Nauton‐Fourteu1*, Shane Tyrrell1, and Andrew C. Morton2

*martin.nauton@icrag‐centre.org

1Earth and Ocean Sciences, Sediment Origins Research Team (SORT) and Irish Centre for Research in

Applied Geosciences (iCRAG), National University of Ireland, Galway, Ireland 2HM Research Associates and CASP, University of Cambridge, Cambridge, UK

Processes such as weathering, hydraulic sorting or mixing can occur during transport and

intermediate storage, preferentially affecting certain minerals due to varying relative stability (e.g.

quartz vs feldspar) and thus modifying the sediment composition. This study investigates bulk

sandstone composition and heavy mineral variations to provide information on the

transport/storage history experienced by the sediment prior to deposition. The apatite‐tourmaline

index (ATi) is believed to be controlled by chemical weathering as during intermediate storage and

transport, apatite grains should be more easily dissolved than tourmaline1. It is expected that, for a

long transport and/or a prolonged storage phase, the apatite‐tourmaline index (ATi) will be relatively

lower than for a sediment with a shorter residence time in the system2,3. It follows that the extent

and duration of any storage phase on the shelf or on the floodplain must be closely related to sea‐

level fluctuations.

This project investigates the mid‐Carboniferous Clare Basin, western Ireland, where glacio‐eustatic

sea‐level fluctuations influenced the deposition of deltaic cyclothems. The Serpukhovian‐Bashkirian

Tullig Cyclothem has been logged and sampled at three locations on coastal outcrops. At two of the

field localities, the deposition shows a delta progradation with a succession of prodelta mud, sandy

mouth bar, interdistributary bay and channelised sand deposits. The third location is interpreted as a

transgressive shelf sand‐body. Petrographic analysis reveals the sandstones at all localities are

mineralogically and texturally mature. Heavy mineral analyses show clear changes in heavy mineral

indices throughout the deposition. ATi values are higher for the channelised sandstones than for the

interdistributary bay or the mouth bar deposits. This could be explained by variations in transport

and/or storage that the sediment experienced prior to deposition, with potentially a more direct

input of sediment through channels than the more mixed interdistributary bay or mouth bar

deposits. Such heavy mineral variations could be due to a change of provenance. For this reason,

source characterisation will be investigated through a multi‐proxy approach using U‐Pb

geochronology of apatite and zircon.

This presentation has emanated from research supported in part by a research grant from Science

Foundation Ireland (SFI) under Grant Number 13/RC/2092 and is co‐funded under the European

Regional Development Fund and by PIPCO RSG and its member companies.

1. Morton, A. C. & Hallsworth, C. Identifying provenance‐specific features of detrital heavy mineral

assemblages in sandstones. Sedimentary Geology. 90, (1994). 2. Morton, A. C. & Hallsworth, C. R. Processes

controlling the composition of heavy mineral assemblages in sandstones. Sedimentary Geology. 124, (1999). 3.

Morton, A. C., Mundy, D. & Bingham, G. High‐frequency fluctuations in heavy mineral assemblages from Upper

Jurassic sandstones of the Piper Formation, UK North Sea: Relationships with sea‐level change and floodplain

residence. Geological Society of America Special Papers. 487, (2012).


72

Provenance and facies analysis evolution of extensional basins: a case study of the Permotriassic Mitu Group (Central Andes, Peru)

Fernando Panca1*, Heinrich Bahlburg1, and Jasper Berndt1

*panca@uni‐muenster.de

1Institute of Geology and Paleontology, University of Münster, Germany

During Permo‐Triassic time, the western margin of Gondwana was characterized by the development of extensional basins, in a transitional period between the Late Paleozoic arc regime and the Andean accretionary orogen initiated in the Early Jurassic. Although important records of both magmatism and sedimentary basins are present (e.g. Kontak et al1., 1990; Sempere et al2., 2002; Panca and Breitkreuz3, 2011; Spikings et al4., 2016; Boekhout et al5., 2018), it is still controversially discussed whether extensional tectonics occurred in a back‐arc or a rift setting. The basin fills consist of stratigraphically poorly controlled volcanosedimentary successions in Peru known as the Mitu Group.

Our study aims at constraining the sedimentology, chronology, spatial development and tectonic setting of evolving depocenters. This study covers field and analytical techniques including single grain geochemical analysis of heavy minerals, whole rock and trace element analysis, U‐Pb geochronology of detrital zircons and rutile, and Lu‐Hf isotope analysis of dated zircons. The Mitu Group is characterized by widespread alkaline and calc‐alkaline volcanic rocks interbedded with thick continental successions deposited in fluvial and alluvial environments. In previous studies, its Late Permian part in the Cusco Region has been considered to overlie the limestones and subordinate sandstones of the lower Permian Copacabana Group above a hiatus and unconformity. However, our combined results of field work and LA‐ICP‐MS dating of detrital zircons indicate the absence of significant hiatus in a portion of Cusco region, exhibiting an environmental transition from marine to continental conditions from 262.6 ± 1.5 Ma (Copacabana Group: Guadalupian) to 260.1 ± 3.7 Ma (Mitu group: Guadalupian‐Lopingian). Additionally, four pyroclastic flow deposits ranging in age from c. 260 Ma to c. 223 Ma indicate that volcanic events in the Mitu basins took place from the late Permian to the late Triassic. A sandstone at the top of the Mitu succession at Pallpa‐Oqoruro section in Cusco region with a maximum depositional age of 197.5 ± 2.7 Ma indicates that Mitu sedimentation may have persisted in southern Peru until the early Jurassic. This study provides a first contribution to an improved understanding of volcanosedimentary facies assemblages, sedimentary basin environments, provenance and timespan of basin fillings, as well as magmatic and tectonic evolution that took place in the southern part of the Mitu basin. 1. Kontak, D.J., Clark, A.H., Farrar, E., Archibald, D.A., and Baadsgaard, H., Late Paleozoic‐early Mesozoic

magmatism in the Cordillera de Carabaya, Puno, southeastern Peru: Geochronology and petrochemistry,

Journal of South American Earth Sciences, v. 3, (1990). 2. Sempere, T., Carlier, G., Fornari, M., Carlotto, V.,

Jacay, J., Arispe, O., Late Permian‐Middle Jurassic lithospheric thinning in Peru and Bolivia, and its bearing on

Andean‐age tectonics. Tectonophysics, vol. 345, (2002). 3. Panca, F. and Breitkreuz, C., The Mitu Group in the

Urubamba valley, NE of Cuzco, Peru: volcanosedimentary facies analysis of an early Andean inverted basin,

Bol. Soc. Geol. Peru 102, (2011). 4. Spikings, R., Reitsma, M.J., Boekhout, F. Mišković, A., Ulianov, A., Chiaradia,

M., Gerdes, A., and Schaltegger, U., Characterization of Triassic Rifting in Peru and implications for the early

disassembly of western Pangaea. Gondwana Research 35, (2016). 5. Boekhout, F., Reitsma, M., Spikings, R.,

Rodriguez, R., Ulianov, A., Gerdes, A., Schaltegger, U., 2018. New age constrains on the palaeoenvironmental

evolution of the late Paleozoic back‐arc basin along the western Gondwana margin of southern Peru. Journal

of South American Earth Sciences, v.82, (2018).


73

Advanced proxies for provenance, erosion and transport mechanisms of modern stream sediments – An application of SEM-based quantitative

mineralogical analysis

Sophia Rütters1*, Raimon Tolosana Delgado 1, and Jens Gutzmer1

*[email protected]

1 Helmholtz Institute Freiberg for Resource Technology, Helmholtz‐Zentrum Dresden Rossendorf,

Freiberg, Germany.

In order to analyse stream sediments for provenance with respect to erosion and transport

mechanisms, several methods are established (e.g. bulk sediment geochemistry, mineralogy

(provided by XRD) and indicator mineral analysis). In this study, we make use of automated

mineralogy by Mineral Liberation Analyser (MLA) as a potentially tool to advance sediment

provenance studies.

The MLA combines backscattered electron (BSE) imaging with energy dispersive X‐ray spectrometry

(EDS) generating compositional data each sediment particles of the sample. The provided data

include particle as well as mineral grain parameters (i.e. size and shape) as well as the mineralogical

composition and properties (e.g. elemental composition, density) of each particle (including

individual constituting mineral grains). The aim is to join the provided parameters in a holistic model

including statistical automatisms. In order to ensure a valid combination of the heterogenic and

voluminous set of data provided by MLA, robust statistical analyses are needed. These statistical

analyses unveil trends and dependencies in suites of related samples. Furthermore, in this study bulk

geochemistry and XRD measurements are integrated to guaranty the quality of the introduced

method and subsequently to critically assess the benefit of the measurement.

The study area is located in the Vogtland region of the Free State of Saxony (Germany). The variscan

bedrocks comprise plutonic (i.e. different types of granite) and metamorphic units (mica schists,

phyllites and quartzites), which are very well studied. Especially since, the Vogtland and the

neighbouring Erzgebirge are well known for the occurrence of granite‐related mineral systems,

represented as polymetallic deposits (skarn‐, vein‐, stockwork‐, and greisen‐type). In addition, this

area is menial populated, suggesting a restricted anthropogenic contaminations of the stream

sediment.

First results of this study, give rise for a clear improvement in the detection of lithological changes of

the source rock composition and transport features of the unconsolidated sediments. This can be

easily identified, based on the modal mineralogy, geochemical changes and grain‐parameter

patterns. In addition, mixing of the material can be calculated with respect lithological changes along

the river path. Another issue, is to detect the anthropogenic contamination of the sampled material

and to balance the impact to the chemical composition.


74

Detection of polymorphous alumosilicates by Correlative Raman Imaging and Scanning Electron Microscopy (Raman-SEM)

Maria Sitnikova1*, Irene Bitz2, and Reiner Dohrmann2

*[email protected]

1 Federal Institute for Geosciences and Natural Resources (BGR) 2 State Authority of Mining, Energy and Geology (LBEG)

Heavy mineral analysis of stream sediment samples is routine analysis in our lab. We would like to

speed up the routine with automatic mineralogy methods. Here we will present one aspect of our

analytical methods validation: how to distinguish the polymorphs like Al2SiO5 and TiO2 with

automated mineralogy methods.

The polymorphs: kyanite, andalusite, sillimanite could not be recognised with EDX‐based Mineral

Liberation Analysis (MLA) method 1. With light optical method these polymorphs are recognisable,

but it is very time‐consuming. The possible way could be a modern analytical approach the

correlative Raman imaging and scanning electron microscopy (RISE)2.

Because of different Al‐coordination in the mineral structures of the polymorphs it is possible to

measure Raman‐Effect and clearly distinguish the species. First the heavy mineral polished block will

be measured with MLA and a “mineral map” will be obtained. Secondly the polymorph grains will be

localised and measured with integrated Raman System. Ideally as final product we will get a MLA‐

Mosaic with distinguished Al2SiO5 polymorphs.

1. Fandrich R., Gu Y., Burrows D., Möller K. Modern SEM‐Based Mineral Liberation Analysis. International

Journal of Mineral Processing, Vol. 84, No. 1‐4, 310‐320 (2007).

2. Confocale Raman Microscopy Ed. Dieing, t., Hollrichter, O.und Toporski, J. Springer Verlag, Berlin Heidelberg

(2010)


75

A database for compositional data

Laura Stutenbecker1*, Adrian Linsel1, Luca Caracciolo2, Pieter Vermeesch3 and Matthias Hinderer1

*[email protected]‐darmstadt.de

1Institute of Applied Geosciences, Technical University Darmstadt, Schnittspahnstrasse, Darmstadt,

Germany 2GeoZentrum Nordbayern, Friedrich‐Alexander‐Universität Erlangen Nürnberg, Schlossgarten,

Erlangen, Germany 3Department of Earth Sciences, University College London, Gower Street, London, U.K.

With the rapid development and improvement of analytical tools our ability to produce ‘Big Data’ is

constantly increasing. Indeed, the pool of compositional data from sediments and source rocks

available for provenance studies is steadily growing. However, this development poses challenges

for researchers to keep track of the relevant literature, as well as to manage, visualize and interpret

those data (e.g. Vermeesch & Garzanti, 2015). In addition, full access is often complicated or not

possible, because data are still being archived on university servers or in the repositories of closed‐

access journals rather than in community databases.

It’s time to think about an integrated database storing compositional data (heavy minerals,

petrography, bulk geochemistry, isotopes, mineral chemistry, …) that is accessible not only to

researchers, but also to end‐users from the industry or from related fields such as archaeology or

forensic sciences.

With this contribution we would like to present our first ideas of a suitable database structure and to

provide a platform to discuss the ideas, needs and suggestions of the WGSG community to

implement and maintain such a database.

1.Vermeesch, P. & Garzanti, E., Making sense of ‘Big Data’ in sedimentary provenance analysis. Chemical

Geology. 409, (2015)


76

Provenance of sands from the SE North Sea: Scandinavian vs. Central European signals

Hilmar von Eynatten*, Philipp Führing, Marius Aschoff, Eric Seest and István Dunkl

*[email protected]

University of Göttingen, Geoscience Center, Department of Sedimentology and Environmental

Geology, Göttingen, Germany

Modern coastal sands of the southwestern North Sea are generally thought to derive from recycling

of Neogene to Quaternary sediments originating from Skandinavia as well as sediment input from

Central Europe mainly through major rivers such as Elbe, Weser, and Rhine. The degree of mixing

between “northern” and “southern” sources mainly depends on location, water depth and age1,2.

Additional complexity is given by the fact that major rivers, which originate from Central European

Variscan basement and Mesozoic cover units, additionally drain Pleistocene glacial deposits of

Scandinavian provenance in their lower reaches, causing admixture of northern provenance signals

to originally purely southern sources such as the Elbe river.

North Sea beach samples were taken along the shoreline from the West Frisian coast at Texel in the

Netherlands to the North Frisian coast at Sylt in northernmost Germany. Additional samples to

constrain endmembers and hinterland mixing were taken from Late Tertiary to Pleistocene

sediments in the N to NE German lowlands, modern fluvial sands of the Elbe River from Dresden

down to the Elbe estuary, and the lower reaches of the Weser River. Methods focus on optical heavy

mineral analysis and zircon U‐Pb dating, complemented by Raman spectroscopy of heavy minerals

and grain‐size analysis using laser particle sizer.

Results allow for discriminating different groups based on trends in heavy mineral composition and

U‐Pb age distributions, supported by Kolmogorow‐Smirnow tests. These are modern sediment from

(1) the West and East Frisian coast/islands, (2) the North Frisian coast and islands, (3) the Elbe River,

(4) the Elbe estuary, and (5) Late Tertiary to Pleistocene outcrops from N and NE Germany. Within

and between the groups distinct trends are observed reflecting processes such as gradual

downstream dilution and admixture in rivers, alongshore sediment transport, and contrasting

current patterns along the northern and southern coasts of the German Bight. Overall, the Central

European signal is strongly diluted in the investigated North Sea sands, implying that most sands are

recycled from older sediments mainly derived from Scandinavia.

1. Schüttenhelm, R.T.E., Laban, C., Heavy minerals, provenance and large scale dynamics of seabed sands in

the Southern North Sea: Baak’s (1936) heavy mineral study revisited. Quaternary Internatio‐nal, 133, 179–193

(2005). 2. Ludwig, G., Figge, K, Schwermineralvorkommen und Sandverteilung in der deutschen Bucht.

Geologisches Jahrbuch, D 32, 23–68 (1979).


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