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Foraminifera and Nannoplankton in Palaeoceanography

The Micropalaeontological Society's Foraminifera andNannofossil Groups Joint Spring Meeting

The National Oceanography Centre Southampton, 15th-17th June 2005

Abstracts and Programme

Sponsors

Ameranda Hess (Denmark) ApS (Emma, is that right?)

Chevron Texaco Energy Technology Company

Leibniz-Institute of Marine Sciences IFM-GEOMAR, Kiel

The Micropalaeontological Society

The National Oceanography Centre, Southampton

Shell Exploration and Production Europe

Statoil Norway ASA

Organizing committee

Emma Sheldon (Geological Survey of Denmark and Greenland, Copenhagen)

Ralf Schiebel (The National Oceanography Centre, Southampton)

Daniela Schmidt (Department of Earth Sciences, University of Bristol)

Joachim Schönfeld (Leibniz-Institute of Marine Science, Kiel)

Jeremy Young (The Natural History Museum, London)

The aim of the meeting

The Micropalaeontological Society's Foraminifera and Nannofossil Groups JointSpring Meeting 2005 continues the tradition of promoting contact and exchange ofideas between workers in their respective groups, and of encouraging cross-linksbetween the disciplines and the expertise from the host institution. The NationalOceanography Centre, Southampton is one of the world's leading centres forresearch and education in marine sciences, earth sciences and ocean technology,and it has developed into a major centre of palaeoceanography. This meeting willfocus on palaoceanographic use of microfossils, insights into their palaeobiology frompalaeoceanographic research, and proxy calibration.

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Programme

Wednesday, 15th June

18:00 - 21:00 Icebreaker party (Cafeteria of the NOCS)

Thursday, 16th June (Lecture Theatre, NOCS)

9:00-9:20 Ralf Schiebel: Welcome

Mesozoic and Cenozic Oceans I (Convenor – J. Schönfeld)

9:20 - 9:40 Oliver Friedrich, J. Erbacher and J. Mutterlose: Cenomanian/Turonian(OAE2) benthic foraminiferal faunas of the Demerara Rise depth transect(ODP Leg 207).

9:40 - 10:00 Nick Hogg: Lower Eocene Oceanography, UK CNS; a core calibratedinterdisciplinary study.

10:00 - 10:20 Robert P. Speijer, S.R. Ernst, E. Guasti and C.Dupuis: Foraminiferalresponse to transient climatic warming at Paleocene/Eocene boundary.

10:20 - 10:40 Philip F. Sexton, P.A. Wilson and R.D. Norris: The Stability of EoceneWarmth and Carbon Cycling - New Records in Foraminiferal Calcite fromDemerara Rise.

10:40 - 11:00 Coffee break

Mesozoic and Cenozic Oceans II (Convenor – J. Schönfeld)

11:00 - 11:20 Emma Sheldon, S. Lassen, J.A.E. Rasmussen and P. Schiøler:Multidisciplinary palaeoecology of Upper Maastrichtian chalks in the DanishCentral Graben – record of a sea-level lowstand.

11:20 - 11:50 Tanja J. Kouwenhoven and G.J. van der Zwaan: An overview of lateMiocene benthic foraminiferal data from the Mediterranean.

11:50 - 12:10 Mike Rogerson, T.J. Kouwenhoven, G.J. van der Zwaan, B.J. O’Neill, C.J.van der Zwan, G. Postma, K. Kleverlaan, and H.J. Tijbosch: BenthicForaminifera from the El Buho Canyon and Fan (Late Miocene of theTabernas Basin, SE Spain).

12:10 - 12:30 Daniela N. Schmidt and M. Kucera: Neogene origin of the modern pelagicniche and its consequences for pelagic carbonate production.

12:30 - 14:00 Lunch time

14:00 – 16:00 Poster Session (in the area outside the lecture theatre)

Pleistocene palaeoceanography (Convenor - J. Young)

16:00 - 16:20 Els Ufkes and D. Kroon: Globorotalia truncatulinoides in the South Atlanticduring the mid-late Pleistocene.

16:20 - 16:40 Maryline J. Vautravers, and N.J. Shackleton: Subtropical North AtlanticOceanic Variability During MIS3: The Planktonic Foraminiferal Record.

16:40 - 17:00 Elena Colmenero-Hidalgo, J.-A. Flores, and F.J. Sierro: Nutricline/pycnoclineand water temperature variations in the South Iberian Margin during the LastGlaciation as revealed by Florisphaera profunda.

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17:00 - 17:20 Elena V. Ivanova, L. Beaufort, and L. Vidal: Planktic foraminifer andcoccolithophorid assemblages of Core MD02-2529 as indicators of climatechanges in the Eastern Equatorial Pacific during the last 135 kyr.

Friday, 16th June (Lecture Theatre, NOCS)

Proxies (Convenor - D. Schmidt)

9:00 - 9:20 Clémentine Griveaud, F. Jorissen, E. Michel and P. Anschutz: Deep-seabenthic foraminifera faunas and stable isotopes from the Portugal margin:preliminary results.

9:20 - 9:40 Hiroshi Kitazato, H. Nomaki, T. Toyofuku and M. Tsuchiya: Foraminifera aspaleoceanographic proxies; biological constraints both from in situ andlaboratory experiments.

9:40 - 10:00 Yunyan Ni, B. Foster, B. Haley, T. Bailey and T. Elliott: Core top calibrationsof Boron isotope paleo-pH proxy.

10:00 - 10:20 Derek Vance: Radiogenic isotopes in foraminiferal carbonate as tracers ofcontinental input to the oceans and ocean circulation.


Ecology I (Convenor - D. Schmidt)

10:50 - 11:10 Lea Numberger, K. von Bröckel, J. Schönfeld and M. Spindler: Observation ofa spring bloom at Kiel Bight, depositional events and reaction of the benthicforaminiferal community.

11:10 - 11:30 Joachim Schönfeld, W.-Chr. Dullo, P. Linke, O. Pfannkuche and A.Rüggeberg: Benthic foraminifera from Deep-Water Coral Mounds in thePorcupine Seabight, NE Atlantic.

11:30 - 11:50 Alexander V. Altenbach, U. Struck, and M. Hiss: Remarks on the ecologyand palaeoecology of the genus Virgulinella Cushman 1932.

11:50 - 12:10 Stefanie Schumacher, F.J. Jorissen, D. Dissard, A.J. Gooday, and K. Larkin:Benthic foraminifera from the oxygen minimum zone of the Pakistancontinental margin - a proxy of bottom water oxygenation.

12:10 - 13:40 Lunch time

Ecology II (Convenor - E. Sheldon)

13:40 - 14:00 Gérald Duchemin, C. Fontanier and F.J. Jorissen: Small sized (63-150 µm)live foraminifera from inner shelf to mid bathyal environments in the Bay ofBiscay during an eutrophic event.

14:00 - 14:20 Michal Kucera: Stationarity of planktonic foraminifer niche since the lastglacial maximum.

14:20 - 14:40 Maria E. Pérez, A.E. Rathburn, J.F. Adamic, J.B. Martin, J. Gieskes, W.Ziebis, J.C. Herguera and C. Paull: Ecology and stable isotopes of livingbenthic foraminifera at different methane seeps (Alaskan margin, Californiamargin, Gulf of California): Implications for the fossil record.


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New approaches (Convenor - E. Sheldon)

15:10 - 15:30 Ralf Schiebel, J. Bollmann and H.R. Thierstein: Automated particle analysisin micropalaeontology.

15:30 - 15:50 Magali Schweizer, J. Pawlowski, T.J. Kouwenhoven and G.J. van der Zwaan:Comparison between morphological and genetic species concepts in thegenera Cibicides and Uvigerina (calcareous benthic foraminifera).

15:50 - 16:10 Kate E. Larkin, A.J. Gooday, D.W. Pond, and B.J. Bett: Fatty acid analysisunravels the role of benthic foraminifera in carbon cycling within the Pakistanmargin oxygen minimum zone.

16:10 - 16:30 Nils Cornelius, A.J. Gooday and T. Cedhagen: Are deep-sea benthicforaminiferans really cosmopolitan?

Saturday, 16th June and Sunday, 17th June

Excursion to the Isle of Wight

Poster presentations:

Lúcia d'Abreu, A. Narciso, E. Salgueiro, A.Voelker, F. Abrantes, M. Cachão, M. and N.J.Shackleton: Changes in upper water-column structure off the Western Iberianmargin during the penultimate glacial (MIS 6): an attempt to unravel theoxygen isotope signal of planktonic foraminifera.

Karl-Heinz Baumann and H. Meggers: Coccolithophores and planktonic foraminifera off NWAfrica: Response to abrupt climate events during the last 45,000 years.

Natasha Bubenshchikova and D. Nürnberg: Benthic foraminifera reflecting the last glacialinterglacial environmental changes on the southeastern Sakhalin slope (theOkhotsk Sea).

Kate Darling, M. Kucera and C.M. Wade: The coiling direction paradox in Neogloboquadrinapachyderma.

Paula Diz, I.R. Hall, R. Zahn and E. Molyneux: Benthic foraminiferal assemblage changes atthe southern Agulhas Plateau during the past 140,000 years.

Kirsty Edgar, P.A. Wilson and P.F. Sexton: Global climate change and fluctuations in theCCD during the middle Eocene: New records from ODP Leg 207, DemeraraRise.

Samantha Gibbs, T.J. Bralower, P.R. Bown and T. Dunkley Jones: Spatial variation inphytoplankton productivity across the Paleocene-Eocene Thermal Maximum:Exceptionally well-preserved nannofossil shelf assemblages from New Jerseyand Tanzania.

Elisa Guasti, R.P. Speijer, H. Brinkhuis, J. Smit and E. Steurbaut: Paleoenvironmentalchange at the Danian-Selandian transition in Tunisia: planktic foraminifera,calcareous nannofossil and organic-walled dinoflagellate cyst records.

Jens O. Herrle, U. Heimhofer, P.A. Hochuli and H. Weissert: Contrasting origins of mid-Cretaceous black shales in the Vocontian Basin: Evidence from palynologicaland calcareous nannofossil records.

Mike Kaminski and F.M. Gradstein: An atlas of Paleogene cosmopolitan deep-wateragglutinated foraminifera.

Meral Köbrich and K.-H. Baumann: Seasonal and interannual variability of coccolithophoresfluxes and species composition in sediment traps off Cape Blanc (NW-Africa).

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Karoliina Koho, T.J. Kouwenhoven, G.J. van der Zwaan, H.C. de Stigter and T.C.E. vanWeering: Recent (Rose Bengal stained) benthic foraminifera from Portuguesemargin canyons.

Regina Krammer, K.-H. Bauman and R. Henrich: Middle to Late Miocene fluctuations in theinitial Benguela Upwelling System revealed by coccolith assemblages (ODPSite 1085A).

Jenny Lezius and H. Kinkel: Coccolith evolution and stable isotopes during the LateMiocene/early Pliocene Biogenic Bloom in the Eastern Equatorial Pacific.

Kenneth Mertens and S. Louwye: Dissolution as indicated by coccoliths in the CariacoBasin, Venezuela.

Alla-Valeria Mikhalevich: The new subfamily Starobogatovellinae (Foraminifera).

Kurt S.S. Nielsen: Palaeomagnetic and Planktonic foraminiferal biostratigraphy of a Plio-Pleistocene section, Rhodes (Greece).

Lennart de Nooijer, I.A.P. Duijnstee and G.J. van der Zwaan: Novel application of MTT-reduction: a viability assay for benthic foraminifera.

Sabrina Renaud and D. N. Schmidt: Morphometrics of the planktic foraminifers G.truncatulinoides and G. ruber: Evolution and ecology affect the response toPleistocene climatic variability.

Aranda da Silva, A.J. Gooday, T. Cedhagen, N. Cornelius and J. Pawlowski: Gromiidprotozoans in the deep sea.

Bettina Schenk, M. Kling and J. Rohrmüller: Cenomanian Foraminifera of Eastern Bavaria.

Jorinde Sprong, E. Guasti, E. Fornaciari and R.P. Speijer: A foraminifera-basedpaleoenvironmental reconstruction of the Danian/Selandian transition in Egypt.

Donata Violanti, S. Trenkwalder, F. Dela Pierre and A. Irace: The Miocene/Plioceneboundary in Piedmont (North-Western Italy). Micropalaeontological analyseson outcrop (Moncucco quarry) and subsurface (Narzole corehole)assemblages.

Silke Voigt, A. Zacke, A.S. Gale and M. Joachimski: Shark teeth oxygen isotopic evidencefor salinity changes and water column stratification in the Palaeocene-EoceneNorth Sea Basin

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Abstracts

Changes in upper water-column structure off the Western Iberianmargin during the penultimate glacial (MIS 6): an attempt to unravelthe oxygen isotope signal of planktonic foraminifera

de Abreu, L. (1, 2), Narciso, A. (3), Salgueiro, E. (1), Voelker, A. (1), Abrantes, F.(1),Cachão, M. (3), and Shackleton, N.J. (2)

(1) INETI I.P., Departamento de Geologia Marinha e Costeira, Estrada da Portela, Alfragide;Portugal.(2) Godwin Laboratory, University of Cambridge, New Museums Site, Cambridge CB2 3SA;United Kingdom. [email protected](3) Departmento de Geologia, Faculdade de Ciencias, Universidade de Lisboa, CampoGrande, 1749-016 Lisboa; Portugal

Sediments of core MD95-2040 were studied in high-resolution to reveal changes in thehydrographic conditions during glacial stage 6. The multi-proxy approach includes variousplanktonic foraminifera-based proxy records and the distribution of Coccolithus pelagicus.The influence of northern Atlantic ice-rafting episodes is evidenced by a polar to subpolarfauna and cold SST. In between the cold spells the influence of a warm surface water mass,probably similar to the modern Azores frontal waters, is indicated by the presence ofsubtropical fauna. This would partially explain the observed variation in the planktonicisotopes and the increment in mid-Stage 6 of the large C. pelagicus morphotype, presentlywith its ecological niche in the Azores region. In full glacial conditions a polar planktonicforaminifera assemblage coincides with the presence of a small C. pelagicus morphotype,that is associated with Heinrich events during the last glacial, and with the deposition of ice-rafting debris. The oxygen isotopic composition of dextral Neogloboquadrina pachydermaand Globorotalia inflata is often lighter than the one of Globigerina bulloides, suggesting thatcalcification took place in distinctive water masses and probably during well-individualisedseasons, thus increasing the thermal and the isotopic contrast. A second ecological modewas identified, during which different species of planktonic foraminifera show a convergencein their habitat, with similar isotopic values. This may indicate enhanced mixing in the upperwater column during parts of MIS 6, in agreement with some of the palaeoproductivityproxies.

Remarks on the ecology and palaeoecology of the genusVirgulinella Cushman 1932

Altenbach, A.V.(1), Struck, U. (1) and Hiss, M.(2)

(1) GeoBio-CenterLMU, Richard-Wagner-Str. 10, D-80333 Muenchen; [email protected], [email protected](2) Geologischer Dienst Nordrhein-Westfalen, De-Greiff-Strasse 195, D-47803 Krefeld;Germany. [email protected]

The taxon Virgulinella was considered an extinct Miocene to Pliocene subgenus or genus forlong. First reports of its tests in modern sediments appeared in 1957, followed by thedescription of the modern remnant species Virgulinella fragilis Grindel and Collen in 1976.Due to the highly variable test morphology of modern Virgulinella, the most distinctmorphological separation from ancient species is given by the extreme delicacy of it's test(wall thickness ca. 1.2 micron). Miocene species of Virgulinella are ubiquitous, mostcommonly found in shelf sediments enriched in phosphorites or glauconite. In congruencewith the literature, we may consider their environment as "normal marine". The modern

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remnant, V. fragilis, shelters anoxic bacteria in endosymbiosis, and thus it is linked to oxygendepleted conditions appropriate for the symbionts. Migration surpassing oxic environmentswould be excluded for this reason, and thus immigration by ships ballast water was madereasonable for the spotty occurrence of modern populations.

Comparing the Miocene and modern environments of Virgulinella, we have to face a veryunpleasant contradiction for our modern view on the functional morphology of benthicforaminifera: the ecological layout of this genus would have changed from "normal marine" inthe Miocene to modern oxygen depleted environments with bacterial symbiosys,accompanied only by negligible morphological changes. But 13C ratios of Virgulinella alreadyshow additional effects to altered pore water chemistry in the Miocene (-1 to -3 ‰ δ13C).They are depleted by 1.5 - 3.5 ‰ and 2.5 - 4.5 ‰ in comparison to Miocene endobenthic andepifaunal foraminifera respectively. Modern Virgulinella from oxygen depleted environmentsrange at -10 to -12 ‰. In addition, teratological test formations are commonly observed inmodern populations off India and Namibia (up to 80%). This seems to indicate a stillpersistent adjustment to most extreme modern environmental conditions, on the edge ofsurvival.

The Stensioeina granulata lineage and its impact on LateCretaceous biostratigraphy.

Bailey, H.W.

Network Stratigraphic Consulting Ltd., Harvest House, Cranborne Road, Potters Bar,Hertfordshire. EN6 3JF. [email protected]

The Stensioeina granulata lineage is thought to have originated from S. pokornyi first foundin Late Cenomanian sediments of the Carpathian trough in Slovakia. Subsequentsubspecies, S. g. interiecta, S. g. humilis and S. g. kelleri, defined by Koch (1977), weredescribed from Turonian sediments in Germany and are frequently recorded in hydrocarbonwell sections drilled in the Dutch, German and Danish offshore areas of the North Sea Basin.The earliest member of the lineage encountered in the Anglo-Paris Basin is the EarlyConiacian subspecies S. granulata levis which is known from southern England and theBoulonnais region of France, possibly introduced into the basin in association with a lateEarly Coniacian transgressive pulse.

Subspecies from Coniacian to mid Santonian chalks (S. g. granulata and S. g. polonica) areubiquitous in their distribution throughout Europe, reflecting their association with successivetransgressive phases. Conversely Late Santonian and Early Campanian subspecies (S. g.perfecta and S. g. incondita), also described originally from Germany, are less widelydistributed, possibly as a result of section loss at this stratigraphic level as a result of regionaltectonic activity.

The lineage appears to come to an abrupt end in mid-Campanian times, with no obvioussuccessor to S. g. incondita. This study suggests possible reasons for the apparentextinction of the group, together with the possible alternative suggestion of an extendedversion of this resilient lineage through into the Paleogene.

Coccolithophores and planktonic foraminifera off NW Africa:Response to abrupt climate events during the last 45,000 years

Baumann, K.-H. and Meggers, H.

FB Geowissenschaften, University of Bremen, Post Box 330440, 28334 Bremen; [email protected]; [email protected]

Various archives from the northern hemisphere such as ice core records and oceansediments were studied in the past decades giving strong evidence of abrupt climatic change

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occurring in high frequency during the last 60 kyrs. Here, we present a sediment core record(GeoB 5546 recovered off Cape Yubi, 27.5°N) of the subtropical NE Atlantic resolving bothHeinrich Events and Dansgaard-Oeschger Cycles in the glacial section. The abrupt climaticchanges strongly modulated the precessional forced palaeoproductivity signal in the NEAtlantic and also influenced the calcareous plankton community.

Coccolithophores and planktonic foraminifera react in a decoupled, almost opposite, way tothe abrupt climatic changes of the last glacial. High contents of planktonic foraminiferatogether with high TOC contents but rather low numbers of coccolithophores occur duringinterstadials, in particular during stage 3. However, species such as Globigerina bulloidesand Calcidiscus leptoporus are indicative for the increased interstadial productivity. Incontrast, low numbers of planktic foraminifera and relatively high numbers ofcoccolithophores occur during stadials of stage 3 as well as during whole stage 2. Wespeculate that the contrast in the calcareous plankton assemblages may be related tochanges in the summer season insolation. Enhanced terrigenous input derived fromwadis/rivers probably is responsible for a near-shore enhancement of the paleoproductivitybut also increased turbidity of the surface water, favouring planktonic foraminifera productionduring the interstadials of stage 3. Since the terrigenous induced enhancement of the marineproductivity outside the insolation maximum is much lower, coccolithophorid production isenhanced in particular during stage 2.

Benthic foraminifera reflecting the last glacial interglacialenvironmental changes on the southeastern Sakhalin slope (theOkhotsk Sea)

Bubenshchikova, N.

P.P.Shirshov Institute of Oceanology, Nakhimovsky 36, Moscow 117997; [email protected]

The last glacial-interglacial sediments of two cores were investigated for sedimentbiogeochemistry, benthic and planktonic foraminifera in order to reconstruct the pastenvironments. The cores are located on the southern and eastern Sakhalin slope at 1265-1370 m water depth within the present Okhotsk Sea Oxygen Minimum Zone (OMZ). Wesuppose that past faunal variations are controlled by the organic matter flux and water masschanges including the outflow of well oxygenated Okhotsk Sea Intermediate Water (OSIW)and the inflow of calcite undersaturated North Pacific Deep Water (NPDW). These processesdetermined the development of OMZ on the Sakhalin slope.

In the last glacial, the Uvigerina auberiana assemblage and sediment biogeochemistry datadocument the low productivity alternated by the periods of the NPDW inflow in the MIS3(Marine Isotope Stage 3) and the OSIW outflow in the MIS2. The anomalously low contentsof planktonic and benthic foraminifera are found predominantly in the MIS3. These eventsare likely a combined result of productivity minima and enhanced inflow of the carbonateaggressive NPDW in the cores locations. In the MIS2 the local increase of the oxic indicatorCibicidoides group shows slightly higher deep intermediate water oxygenation and/or bottomcurrent activity. We suggest that the OMZ in the MIS2 was slackened essentially due to theenhanced OSIW production. The biogeochemical data and benthic fauna dominated byTakayanagia delicata and Uvigerina akitaensis show the first lower peak of productivity at theMelt Water Pulses (MWP) 1A and the second higher maxima of productivity at the MWP1Bcaused by deglacial climate warming and the sea level rising. After the MWP1B benthicfauna indicates the strengthening of the OMZ by the growth of dysoxic indicator Brizalinaspissa associated with maximal productivity and reduced OSIW ventilation. In the Holocenethe Islandiella norcrossi assemblage is characterized by anomalously low abundances and,thus, does not reflect adequately the relatively high productivity recorded by the total organiccarbon, opal, carbonate and planktonic foraminifera. A combined effect of the relatively high

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organic matter flux, the inflow of calcite undersaturated NPDW and substrate changes aresuggested to have a principal impact on benthic foraminifera in the Holocene.

Nutricline/pycnocline and water temperature variations in the SouthIberian Margin during the Last Glaciation as revealed byFlorisphaera profunda

Colmenero-Hidalgo, E. (1, 2), Flores, J.-A. (1) and Sierro, F. J. (1)

(1) Área de Paleontología, Dept. Geología, Universidad de Salamanca, Plaza La MercedS/N, 37008 Salamanca, Spain. [email protected], [email protected](2) Present address: School of Earth, Ocean and Planetary Sciences, Cardiff University,Park Place, Main Building, Cardiff CF10 3YE, Wales, United Kingdom. [email protected]

Quantitative studies on coccolithophore populations have been carried out in marinesediment cores MD95-2043 (36º9‚N, 2º37‚W; 1841 m water depth; Alboran Sea, WesternMediterranean) and M39029-7 (36º2.5‚N, 8º13.8‚W; 1917 m water depth; Gulf of Cadiz, NEAtlantic). Coccolithophore assemblages from both cores provide high-resolution records ofMIS 1 to 3 allowing detailed palaeoceanographic and palaeoclimatic reconstructions of thelast 50 kyrs (Colmenero-Hidalgo et al., 2004).

Florisphaera profunda is the only lower photic zone calcareous nannoplankton species inboth cores, usually living between 80-120 m deep with a minimum temperature threshold atthat depth of 10-12ºC. Variations in its abundance have been frequently used to monitorchanges in turbidity or in the position of the nutricline. Maximum peaks in the Gulf of Cadiz(up to 40%) during the coldest intervals of the Last Glacial period (i. e. Heinrich Events andsome of Dansgaard-Oeschger Stadials) have been interpreted as the probable result of highupper photic zone turbidity and upper water column stratification. On the contrary, itsbehaviour in the Alboran Sea shows that despite nutricline shallowing and nutrientenrichment in its depth during these same cold events (Pérez-Folgado et al., 2003),temperatures were far below 10-12ºC. In the Deglaciation, the incipient temperature increasewas probably enough to trigger increases of Florisphaera profunda at H1 and YD, theintervals of shallower nutricline/pycnocline in the area.Colmenero-Hidalgo, E., Flores, J.-A., Sierro, F.J., Bárcena, M.A., Löwemark, L., Schönfeld, J. and

Grimalt, J.O., 2004. Ocean surface water response to short-term climate changes revealed bycoccolithophores from the Gulf of Cadiz (NE Atlantic) and Alboran Sea (W Mediterranean).Palaeogeography, Palaeoclimatology, Palaeoecology, 205, 317-336.

Pérez-Folgado, M., Sierro, F.J., Flores, J.-A., Cacho, I., Grimalt, J.O., Zahn, R. and Shackleton, N.,2003. Western Mediterranean planktic foraminifera events and millennial climatic variability duringthe last 70 kiloyears. Marine Micropaleontology, 48, 49-70.

Are deep-sea benthic foraminifera really cosmopolitan?

Cornelius, N. (1), Gooday, A.J. (1) and Cedhagen, T. (2)

(1) Southampton Oceanography Centre, Empress Dock, European Way, Southampton SO143ZH, UK. [email protected](2) Department of Marine Ecology, University of Aarhus, Finlandsgade 14, 8200 Aarhus N,Denmark. [email protected]

Wet-sorting of entire‚ live foraminiferal assemblages (i.e. including soft-walled species) frommulti- and box-corer samples collected during the ANDEEP II expedition in the Weddell Sea(1100 - 4975 m water depth) and S. Sandwich Trench (6300 m water depth) has revealedabundant and diverse foraminiferal assemblages. Densities generally decreased with waterdepth. The proportion of calcareous species also decreased with depth whilemonothalamous taxa and komokiaceans increased, but considerable numbers of calcareousforaminifera were still present well below the Calcium Carbonate Compensation Depth(CCD). The samples yielded 205 live foraminiferal species, of which only 93 were described.

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These observations are reinforced by preliminary data from the recent ANDEEP IIIexpedition (Jan 22nd to April 6th 2005) to the Weddell and Bellingshausen Seas during whichwe recognized about 330 benthic foraminiferal species, of which less than 100 are described.Most of the undescribed species in ANDEEP samples are komokiaceans or soft-shelledmonothalamous forms. Some are highly distinctive and may be confined to the SouthernOcean. On the other hand, the majority of the described species are well known from theNorthern Hemisphere, for example, the upwelling area off NW Africa, the GreenlandNorwegian Sea and the Barents Sea. Examples include Ammolagena clavata,Cribrostomoides subglobosa, Adercotryma glomeratum, Cyclammina cancellata,Hormosinella distans, Edgertonia floccula, Bulimina marginata, Nuttallides umbonatus,Epistominella exigua and Oridorsalis umbonatus. However, these identifications are basedon morphological criteria. During ANDEEP II, we collected specimens of many species formolecular analyses. We plan to compare DNA sequences from these species with thosefrom similar morphospecies obtained at deep-sea Arctic sites during expeditions thissummer. This comparison will form a basis for exploring the question: are cosmopolitandeep-sea foraminiferal morphospecies really single species or do they include a number ofmorphologically similar cryptic species?

The coiling direction paradox in Neogloboquadrina pachyderma.

Darling, K. (1), Kucera, M. (2) and Wade, C. M. (3)

(1) Grant Institute of Earth Science/Institute of Evolutionary Biology, University of Edinburgh,Edinburgh, UK. [email protected](2) Institut für Geowissenschaften, Eberhard-Karls Universität Tübingen, Tübingen,Germany. [email protected](3) Institute of Genetics, University of Nottingham, Nottingham, [email protected]

Planktonic foraminifera with trochospirally arranged chambers can produce shells with twodifferent coiling directions. Some morphospecies show a strong preference for either right-handed (dextral) or left-handed (sinistral) coiling, while other morphospecies appear in mixedcoiling proportions varying around a midpoint value. Some display a pattern of distinct shiftsin their coiling ratios spatially and through time. Although the underlying mechanismscontrolling coiling direction are not understood, many workers have assumed it to be amorphological feature reflecting ecophenotypic variation and have used coiling ratiosextensively for palaeoenvironmental reconstruction. Recent genetic studies now clearlydemonstrate that coiling direction in planktonic foraminifera is a genetic trait, heritablethrough time and not environmentally controlled. Previously reported links between coilingand environmental factors result from the different ecological preferences of the geneticallydistinct coiling types.

Neogloboquadrina pachyderma is the most important provider of palaeoproxies on the stateand variation of high latitude oceans in the Quaternary. It has two distinct coiling forms withvirtually exclusive distributions that appear to be controlled by water temperature. Thegenetic evidence shows that the two opposite coiling morphotypes diverged many millions ofyears ago and they have distinctly different ecologies. In combination with fossil evidence,biogeography and ecology, the degree of genetic distinction between the two coiling types ofNe. pachyderma strongly implies that they should be considered different species. Thegenetic evidence also demonstrates a low level (< 3%) aberrant coiling associated with eachmorphotype posing a serious nomenclature problem for taxonomists andpalaeoceanographers alike. The presence of aberrant coiling and the continual need forpalaeoceanographers to refer to coiling direction in the literature demands the re-classification of the right coiling Ne. pachyderma genotypes as a distinct species to simplifynomenclature and reference. We propose the adoption of the widely recognised nameincompta for the dextral morphospecies.

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Benthic foraminiferal assemblage changes at the southern AgulhasPlateau during the past 140,000 years

Diz, P. (1), Hall, I.R. (1), Zahn, R. (1, 2) and Molyneux, E. (1)

(1) School of Earth, Ocean and Planetary Sciences, Cardiff University, Main Building, ParkPlace, CF10 3YE Cardiff, United Kingdom.(2) Institució Catalana de Recerca i Estudis Avançats, ICREA, i Universitat Autónoma deBarcelona, Institut de Ciencia i Tecnología Ambientals, ICTA, Edifici Cn Campus UAB, E-08193 Bellaterra, Spain.

Benthic foraminiferal assemblages and stable oxygen and carbon isotopes fromEpistominella exigua along core MD02-2589 (41º26.03´S, 25º15.30´E, 2660 m water depth)are used to infer palaeo-productivity changes at the South Agulhas Plateau. The core islocated at the position of the present day Subtropical Front (STF) within the AgulhasRetroflection current regime. It is optimally located to monitor leakage of warm Indian Oceanwaters into the south Atlantic Ocean and changes in productivity associated with the frontalsystem formed by the Agulhas Return Current (ARC) and the Subtropical Convergence(STC).

Stratigraphy for core MD02-2589 is based on AMS 14C dates and a high resolution planktonicoxygen isotope record along the core (Molyneaux et al., unpublished data). Thesedimentation rate varied between 3.3 and 29 cm/kyr with an average of 8.7 cm/kyr. Thecore shows substantial down-core fluctuations in faunal composition. Relative abundance ofphytodetritus exploiting species Alabaminella weddellensis and E. exigua (Gooday, 1993)are unrelated. A. weddellensis is the most common species throughout the core, but E.exigua is more abundant during MIS 1 and 5e, indicating periods of occasionally high butpulsed deposition of organic matter at the sea floor. More sustained food supply occurred atthe end of Terminations I and II and during MIS 5a and 5b when N. iridea and Uvigerina spp.(TI, TII) and E. vitrea (MIS 5a, b) compete with and outnumber E. exigua and A.weddellensis. High percentages of N. iridea, a shallow infaunal species (Gooday andHudges, 2002), at the Last Glacial Maximum suggest a measurable increase in the overallorganic carbon flux arriving at the seafloor probably caused by increased productivity inresponse to enhanced wind stress and a southward moving STF.

Preliminary measurements of stable carbon isotopes in E. exigua show that δ13C values arelow (-0.4‰ to -1.0‰), with minimum values occurring at the LGM coincident with peak N.iridea abundance. These data are consistent with a contribution of 12C enriched pore watersderived from the decomposition of the phytodetritus layer deposited at the seafloor.Tentatively we use the δ13C record of E. exigua as a proxy of organic carbon flux and primaryproductivity as suggested by Corliss et al. (2001).Gooday, A.J., 1993. Deep-sea benthic foraminiferal species which exploit phytodetritus: characteristic

features and controls on distribution. Marine Micropaleontology, 22, 187-205Gooday, A.J. & Hudges, J.A., 2002. Foraminifera associated with phytodetritus deposits at a bathyal

site in the northern Rockall Trough (NE Atlantic): seasonal contrast and a comparison of stainedand dead assemblages. Marine Micropaleontology, 46, 83-110.

Corliss, B.H., Sun, X., Brown, Ch.W., McCorkle, D.C., Showers, W.J. & Hidgon, D.M., 2001. Theinfluence of primary productivity and seasonality of productivity on deep-sea benthic foraminifera.GSA Annual Meeting, November 5-8, 2001.

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Small sized (63-150 µm) live foraminifera from inner shelf to midbathyal environments in the Bay of Biscay during an eutrophicevent

Duchemin, G., Fontanier, C. and Jorissen F.J.

Laboratory of Recent and Fossil Bio-Indicators, University of Angers, 2 boulevard Lavoisier,49045 ANGERS cedex 01; France. LEBIM, Ker Châlon, 85350 ILE D'YEU; [email protected], [email protected], [email protected]

Living foraminiferal faunas of the 63-150 µm size fraction have been investigated along acomposite transect from inner shelf (80 m water depth) to lower middle slope (2000 m waterdepth) in the Bay of Biscay. The eleven stations were sampled in April 2002 and March2004. Earlier studies on the temporal variability of phytoplankton primary production indicatethat our stations were sampled at the most eutrophic period of the year. In response to thedecreasing exported organic matter flux to the sea floor with increasing water depth,foraminiferal standing stocks show a trend from high values (about 1400-2000 specimensper 50 cm3) on the continental shelf (100-140 m water depth) and the upper slope (550 m) tomuch lower values at mid bathyal stations (about 400 specimens per 50 cm3). At all stations,the faunas contain an important amount of small opportunistic species that are favoured byseasonal phytodetritus inputs. From coastal to mid bathyal stations, foraminiferal faunas aredominated successively by: (1) Textularia porrecta (coastal area); (2) Nonionella iridea,Cassidulina carinata and Bolivina ex. gr. dilatata (northern outer shelf) or Bolivinadilatata/spathulata and Bolivina subaenariensis (southern outer shelf); (3) Epistominellaexigua and Uvigerina peregrina (upper middle bathyal); and (4) Nuttallides pusillus andGavelinopsis translucens (lower middle bathyal). This faunal succession could be related tothe water depth, which influences directly the amount of organic matter exported to the sea-floor, and perhaps to the quality of this organic matter, which could explain differences offoraminiferal composition between the northern and southern part.

Global climate change and fluctuations in the CCD during themiddle Eocene: New records from ODP Leg 207, Demerara Rise.

Edgar, K. M., Wilson, P. A. and Sexton, P. F.

Southampton Oceanography Centre, School of Ocean and Earth Science, EuropeanWay, Southampton, SO14 3ZH, UK. [email protected]

The middle Eocene (37-49 Ma) is traditionally regarded as a period of long-term cooling thatrepresents the transition between the early Eocene greenhouse and the early Oligoceneicehouse. However, because of the poor quality of deep sea sedimentary sequencesrecovered of this age, the nature of this transition remains relatively badly constrained. Themajority of studies are confined to Southern Ocean sites and suggest that the middle Eocenewas in fact punctuated by at least several short stable isotope excursions superimposed onthe underlying long term cooling trend. One of the most prominent of these excursions is apronounced warming event at 41.6 Ma seen in surface and intermediate water temperaturesat Site 690. Elsewhere, work in the Pacific has demonstrated that the onset of majorAntarctic ice sheets across the Eocene/ Oligocene boundary was intimately associated witha pronounced decrease in ocean acidity (CCD deepening) (Coxall et al, 2005).

Here we report new stable isotope records in benthic foraminiferal calcite of middle Eoceneage from ODP Leg 207 (Demerara Rise) in the tropical Atlantic. A high sedimentation rate of~2cm/kyr combined with a well-defined magnetostratigraphy facilitates high resolutionexamination of the stability of global climate during this transition interval.Boharty, S. M. and Zachos, J. C., 2003. Significant Southern Ocean warming event in the late middle

Eocene. Geology, 31, 1017-1020.

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Coxall, H. K., Wilson, P. A., Pälike, H., Lear, C. H. and Backman, J. 2005. Rapid stepwise onset ofAntarctic glaciation and deeper calcite compensation in the Pacific Ocean. Nature, 433: 53-57.doi:10.1038/nature03135.

Cenomanian/Turonian (OAE2) benthic foraminiferal faunas of theDemerara Rise depth transect (ODP Leg 207)

Friedrich, O. (1), Erbacher, J. (2) and Mutterlose, J. (3)

(1) Bundesanstalt für Geowissenschaften und Rohstoffe, Stilleweg 2, 30655 Hannover;Germany. [email protected] (2) Bundesanstalt für Geowissenschaften und Rohstoffe, Stilleweg 2, 30655 Hannover;Germany. [email protected] (3) Institut für Geologie, Mineralogie und Geophysik, Ruhr-Universität Bochum,Universitätsstrasse 150, 44801 Bochum; Germany. [email protected]

ODP Leg 207 recovered thick successions of Late Cretaceous organic-rich strata along adepth transect of 5 sites (3192 – 1899 mbsl) on Demerara Rise, 400 km north off Surinam,western tropical Atlantic. Cenomanian to Turonian sediments with Oceanic Anoxic Event 2(OAE2) were recovered from different sites. This interval is characterised by very high TOCvalues of up to 29 %. Based on high resolution δ13Corg-records from four Sites, achemostratigraphic framework was established for Demerara Rise black shale sedimentsincluding OAE2. This chemostratigraphy allows us to correlate changes in the benthicforaminiferal assemblages of four sites around OAE2. Along the depth transect, Site 1258 isthe deepest and shows high fluctuations in the assemblages that correlate to changing TOCvalues in the sediments. Samples without benthic foraminifera are characterized by very highTOC values (above ~10%), whereas samples with lower TOC values contain benthicforaminifera. Generally, the faunas are characterized by only few taxa that are tolerant tooxygen deficiency, like Bolivina, Praebulimina, and Neobulimina. Very high benthicforaminiferal numbers (BFN) occur some meters below OAE2, whereas the excursioninterval is characterized by low BFN and diversity, indicating very low oxygen contents, butnot complete anoxia during distinctive intervals of OAE2. Above the excursion, slowlyincreasing BFN and diversities indicate slightly increasing oxygen content which isinterrupted by several phases of complete anoxia.

Benthic foraminiferal assemblages of the shallower Site 1261 reflect anoxic conditions duringmost of the studied interval and therefore a more stable position within a proposed oxygenminimum zone (OMZ). Times of oxygen availability, as indicated by the occurrence of benthicforaminifera can be correlated to high BFN in Site 1258. First results from the shallowest Site1259 and from the very condensed OAE2 of Site 1260 support the existence of a fluctuatingOMZ.

Spatial variation in phytoplankton productivity across thePaleocene-Eocene Thermal Maximum: Exceptionally well-preservednannofossil shelf assemblages from New Jersey and Tanzania

Gibbs, S. J. (1), Bralower T. J. (1), Bown, P. R. (2) and Dunkley Jones, T. (2)

(1) Department of Geosciences, The Pennsylvanian State University, University Park,Pennsylvania 16802, USA. [email protected], [email protected](2) Department of Earth Sciences, University College London, Gower Street, London WC1E6BT, UK. [email protected], [email protected]

Significant transformations in the global biosphere accompanied dramatic global warmingand profound perturbation of the carbon cycle during the Paleocene-Eocene ThermalMaximum (PETM, ~55 Ma). These abrupt environmental changes have been linked to amassive release of carbon into the ocean-atmosphere system. Increased phytoplanktonproductivity has been invoked to cause subsequent CO2 drawdown, cooling, and

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environmental recovery. However, interpretations of geochemical and biotic data differ onwhere this increased productivity occurred. Here we present high-resolution nannofossilassemblage data from a number of shelf sections including the U.S. Geological Survey drillhole at Wilson Lake, Ocean Drilling Program (ODP) Leg 174X Bass River drill hole (bothNew Jersey), and Kilwa, Tanzania (drilled as part of the Tanzanian Drilling Project). We alsoshow data from an open-ocean location, ODP Site 1209 (palaeo-equatorial Pacific).Nannofossil assemblage changes indicate highly variable responses to this climatic eventacross the environmental trophic spectrum. Low productivity, open ocean sites demonstratea global but transient increase in oligotrophy, which may have resulted from a widespreaddeepening of the thermocline. In contrast, shelf-slope productivity variations were morelocalized with mesotrophic communities spatially restricted to areas close to nutrient sourcesvia increased runoff. The relatively limited area of shallow shelves may have provided adisproportionately large carbon sink and this phytoplankton productivity may have played animportant role in driving the massive drawdown of CO2 after the peak of the PETM.

Deep-sea benthic foraminifera faunas and stable isotopes from thePortugal margin : preliminary results

Griveaud, C. (1), Jorissen, F. (1), Michel, E. (2) and Anschutz, P. (3)

(1) Laboratoire d‚Etude des Bio-indicateurs Actuels et fossiles, UPRES EA2644, Universitéd‚Angers, 2bd Lavoisier, 49045 Angers Cedex (France)(2) Laboratoire des Sciences du Climat et de l'Environnement CNRS-CEA, Allée de laTerrasse, 91198 Gif/Yvette cedex (France)(3) Département de Géologie et Océanographie, UMR CNRS 5805 EPOC, UniversitéBordeaux1, Avenue des facultés, 33405 Talence cedex (France)

The ecology (faunal density, composition, microhabitats) of benthic foraminifera from threedeep stations (1000m, 2000m and 3000m) of the Portugal margin (Northwest Atlantic, 37-38°N) has been studied. Six cores were picked for each station. In order to improve theunderstanding of factors controlling the spatial distribution of the faunas, the chemistry of thesediment (O2, NO3-∑) has also been analysed. Stable isotopes measurements (δ18O, δ13C)from species of four key genera that have different microhabitats (Cibicidoides/Fontbotia,Uvigerina, Melonis and Globobulimina) are still in process. We will show here preliminaryresults.

Faunal densities decrease with increasing water depth, following as expected the diminishingorganic matter flux that reaches the see floor at greater depths. However one core at stationFP9 (3000m) exhibits a surprisingly high density due to the presence of a worm burrow, withthe apparition of reactive species such as Pullenia bulloides, Fursenkoina sp., and Pyrgoelongata. The deep infaunal Globobulimina affinis shows in each station a maximum ofabundance at "oxygen zero” depth, which is in agreement with previous studies.

Interspecific differences in stable isotopic composition are related to the differentmicrohabitats, with deep infaunal species (Globobulimina affinis) having lighter values thanshallow infaunal species (Uvigerina mediterranea). The Uvigerina species, however, show awide scatter in δ18O as well as δ13C in function of the size of the specimen measured butfurther analysis are still expected to confirm this trend.

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Paleoenvironmental change at the Danian-Selandian transition inTunisia: planktic foraminifera, calcareous nannofossil and organic-walled dinoflagellate cyst records

Guasti, E.(1), Speijer, R.P.(2), Brinkhuis, H. (3), Smit, J. (4) and Steurbaut, E., (5)

(1) Department of Geosciences (FB 5), Bremen University, P.O.Box 330440, 28334Bremen, Germany. [email protected](2) Department of Geography and Geology, K.U.Leuven, Redingenstraat 16, 3000 Leuven,Belgium. [email protected](3) Laboratory of Palaeobotany and Palynology, Utrecht University, Budapestlaan 4, 3584CD Utrecht, The Netherlands. [email protected](4) Department of Sedimentology, Faculty of Earth and Life Sciences Vrije Universiteit, deBoelelaan 1085 1081HV Amsterdam, the Netherlands. [email protected](5) K.B.I.N., Vautierstraat 291000 Brussel Belgium. [email protected]

We document paleoenvironmental change across the Danian-Selandian transition (plankticforaminiferal interval P2-P3b; Calcareous Nannofossil Zone NP4, Subzones NTp7-NTp8A;61-59 Ma) in three localities in NW Tunisia (Ain Settara, Elles and El Kef). Diversification ofPaleogene planktic foraminifera with the evolution of muricate and photosymbiotic lineagesAcarinina, Morozovella and Igorina is recorded during this interval. The present study aims tounderstand early Paleogene geo-biosphere changes in the southern Tethys, analyzing theevolution of surface water conditions. All the studied localities represent outer neriticdeposition. Paleoenvironmental changes are explored by combining planktic foraminiferaland organic dinocyst assemblages and relative proxies (planktic/benthic ratio, numbers ofplanktic foraminifera per gram, peridinioid/gonyaulacoid ratio; terrestrial/marine ratio). Ourrecords indicate that the environment evolved from an initially oligotrophic, open marine,outer neritic setting in Zone P2-P3a towards a shallower and nutrient-rich setting from thebase of Subzone P3b. This change is marked by a sudden change in organic-dinocystassemblages, characterized by a peak of P-cysts (Cerodinium and Lejeunecysta) and anupwards decrease in deeper benthic taxa. Associated to these dinocysts assemblages, thelowest occurrence of Apectodinium is recorded suggesting major environmental (andclimate) perturbations. The start of the P-cysts peak corresponds to a substantial change incalcareous nannofossil assemblages, marked by the first appearance of Fasciculithus and aslight, but distinct increase in near-shore taxa (essentially Pontosphaera).

Contrasting origins of mid-Cretaceous black shales in theVocontian Basin: Evidence from palynological and calcareousnannofossil records

Herrle, J.O.(1), Heimhofer, U.(2), Hochuli, P. A.(3) and Weissert, H. (4)

(1) Southampton Oceanography Centre, School of Ocean & Earth Science, European Way,SO14 3ZH Southampton, UK [email protected](2) University of Oxford, Oxford OX1 3PR, UK uli.heimhofer@earth(3) Palaeontological Institute, University of Zurich, Karl Schmid-Strasse 4, 8006 Zurich, [email protected](4) Geological Institute, ETH Zurich, Sonneggstrasse 5, 8092 Zurich, [email protected]

Detailed records of spore-pollen assemblages, particulate organic matter (OM), dinoflagellatecysts and calcareous nannofossils provide new insights into the palaeoclimatic andpalaeoceanographic conditions during formation of mid-Cretaceous black shales in theVocontian Basin (SE France). The early Aptian Niveau Goguel, which corresponds to theOAE1a, and the regionally distributed late Aptian Niveau Jacob have been studied with

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regard to changes in terrestrial vegetation patterns, terrigenous inputs and surface waterproductivity.

Palynological results from both black shales exhibit a rich and stable floral pattern,dominated by various ferns, different types of cycads, bennettites as well as by severalconifer families. Dinoflagellate cyst assemblages and the calcareous nannofossil-basednutrient-index show no prominent changes in surface water productivity across both blackshale intervals. Significant variations are observed in terrestrial detrital input indicated bychanges in abundances of marine and terrestrial palynomorphs. The laminated, OM-richhorizons of the Niveau Goguel interval reflect deposition during times of reduced siliciclasticinput. These episodes of pronounced condensation were accompanied by anoxic conditionspreventing degradation of the marine-derived OM. In contrast, the Niveau Jacob ischaracterised by a strong increase in terrestrial palynomorphs, most probably reflecting anabrupt increase in riverine runoff. The enhanced terrestrial OM input may have triggeredoxygen-depletion in bottom waters, resulting in increased OM preservation.

Our results highlight the variety of processes, controlling the accumulation of OM in theVocontian Basin and illustrate, that enhanced surface water productivity is not anindispensable prerequisite for the formation of mid-Cretaceous black shales. Discrepanciesbetween the results from the Vocontian Basin and data from other Tethyan localities mightbe explained by differing regional palaeoceanographic settings, resulting in differentresponses to global palaeoenvironmental change. An important precondition for black shalesformation was most probably given by the rather low deep-water oxygen concentrations ofthe mid-Cretaceous ocean basins, resulting in a strong propensity towards anoxic bottomwaters.

Lower Eocene Oceanography, UK CNS; a core calibratedinterdisciplinary study.Hogg, N.

[email protected]

An unprecedent integrated, multidisciplinary opportunity to study the Lower Eocene(Ypresian) North Sea ocenaographic reconnection has been afforded in cored wells fromShell's Gannet D Field, UK Central North Sea (CNS). A full description and discussion will bepresented of micropalaeontological, palynological and ichnological responses to the openingup of the restricted North Sea basin in the lowermost Horda Formation, following restrictedconditions posed on the basin across the Paleocene/Eocene boundary.

Planktic foraminifer and coccolitophorid assemblages of CoreMD02-2529 as indicators of climate changes in the EasternEquatorial Pacific during the last 135 kyr

Ivanova, E.V. (1), Beaufort, L. (2) and Vidal, L. (2)

(1) Shirshov Institute of Oceanology RAS, Nakhimovsky Prosp. 36, Moscow, 117997,Russia. [email protected](2) CEREGE, Europole de l'Arbois, Aix en Provence, Cedex 04, F-13545 [email protected]

A quantitative study of planktic foraminiferal and coccolithophore assemblages in the upper18 m of Core MD02-2529 (08°12.5' N, 84° 07.5' W, w.d. 1619 m) retrieved below thesoutheastern edge of the Costa Rica dome provides a new insight into productivity variationsand ENSO dynamics in EEP during the last 135 kyr. PCA carried out on the combined phyto-and zooplankton data demonstrates that species distribution in both groups mainly reflectbioproductivity, i.e. thermocline depth, and dissolution intensity. We found pronouncedtemporal variations in microfossil assemblages. Whereas interglacial assemblages are

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characterized by high content of deep-dwelling G. menardii, rather oligotrophic surface-dwelling G. ruber and G. trilobus,and deep photic zone species F. profunda, species relatedto fertile upwelling waters as G. bulloides, G. glutinata, diverse coccolitophorids and deep-dwelling cold-water N. dutertrei and N. pachyderma generally proliferate during glacials anddeglaciations. A persistent occurrence of minor deep-dwelling species G. inflata, known tobe typical of eastern margins of subtropical gyres, likely points to a relatively short-termevents of lateral advection of cooler subsurface waters during MIS 2 and 4, sometimesdecoupled with the events of intensified upwelling and shoaling of the thermocline when G.bulloides and G. glutinata increase in abundance. The end of MIS 2 is characterized by amaximum of calcareous microfossils preservation, followed by a gradual increase ofdissolution from the end of Termination I to Holocene, except for a short-term spike of highplanktic and benthic foraminiferal abundance related to a better preservation at TerminationI. An increase in productivity during glacials and deglaciations most probably indicative of thethermocline shoaling in turn may be controlled by a glacial extension of Costa Rica domeand/or by stronger Papayago winds coming from the Caribbean Sea. These finding are inline with more frequent La-Ninas or stronger tradewinds during glacials.

An Atlas of Paleogene Cosmopolitan Deep-Water AgglutinatedForaminifera

Kaminski, M.A (1) and Gradstein, F.M. (2).

(1) Department of Earth Sciences, University College London, London WC1E6BT, UK.(2) Museum of Geology, University of Oslo, N-0318 Oslo, Norway.

As a step towards the documentation of the global deep water agglutinated foraminiferalfaunas through geologic time, we have prepared an illustrated Atlas of Paleogene Deep-Water Agglutinated taxa. These faunas started to flourish in deeper water basins as early asMiddle Jurassic, with major phases of evolutionary expansion in the Aptian-Turonian,Campanian, late Paleocene, Early Eocene and Middle Miocene.

The Atlas, which we began as a taxonomic project in 1979 at the Bedford Institute ofOceanography in Dartmouth, N.S., is intended to serve as a reference guide formicropalaeontologists working with agglutinated benthic foraminifers in deep marine,siliciclastic strata of Paleogene age around the world, and is intended to be a companionvolume to the "Van Morkhoven et al. Atlas” of deep-water calcareous benthic foraminifera.Some of the agglutinated taxa covered in the Atlas are stratigraphically long ranging, whileothers either appeared in Late Creta-ceous time or extend into Neogene.

The 130 Agglutinated Taxa are grouped in Linnean taxonomic units using fossil shellmorphology, which represent the majority of species to be expected in deep-marine clasticsediments. For each of these valid species we provide illustrations – mostly based on typematerial – with one or more plates of SEM and optical photographs, and/or hand drawings.There is concise description for each species, followed by a discussion of its paleogeographyand stratigraphic occurrence. The Atlas begins with an intro-duction outlining the history ofinvestigations, and discusses the most important collections. The second chapter summa-rises the Paleoecology and its spin-off Paleobathymetry, a subject that is in demand for thestudy of deep water basins. Chapter three deals with biostratigraphical record of DWAF inoffshore eastern Canada, in the North Sea, Offshore Norway, Norwegian Sea, Barents Sea,Carpathian Basins, southern European Tethyan basins, India, and Trinidad/Venezuela.Each main area of investigation has a stratigraphic range chart for key taxa. The followingsection contains the main course of this Atlas: Systematic Taxonomy. This is followed by themaster reference listing and the species index. The "Atlas of Paleogene Cosmopolitan Deep-Water Agglutinated Foraminifera” is available from the Grzybowski Foundation.Kaminski, M.A. & Gradstein, F.M. (2005). Atlas of Paleogene Cosmopolitan Deep-Water Agglutinated

Foraminifera. Grzybowski Foundation Special Publication, 10, 547 pp.

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Foraminifera as paleoceanographic proxies; biological constraintsboth from in situ and laboratory experiments.Kitazato, H. (1), Nomaki, H. (1), Toyofuku, T. (1) and Tsuchiya, M. (2)

(1) Institute for Research on Earth Evolution (IFREE), Japan Agency for Marine-EarthScience and Technology (JAMSTEC), Natsushima-cho 2-15, Yokosuka 237-0061, [email protected], [email protected], [email protected](2) JSPS Research Fellow, Extremobiosphere Research Center (XBR), Japan Agency forMarine-Earth Science and Technology (JAMSTEC), Natsushima-cho 2-15, Yokosuka 237-0061, JAPAN [email protected]

Foraminifera are known as an excellent indicator both for modern and ancient oceanicenvironments. This is mainly supported by the empirical evidences that foraminifera changetheir test morphologies and/or chemical compositions in response to ambient environmentalconditions. However, we have no concrete proofs how foraminifera adapt their shapes orchemical compositions to ambient environments. Both culture experiments and DNAanalyses are direct ways to understand foraminiferal biology as theoretical constraints forpaleo-environmental proxies.

Obviously, several assumptions are existed at the time when we use foraminifera forreconstructing paleoceanographic condition. Foraminiferal tests are sensitive test-tube forindicating ambient environments. Foraminiferal communities are important components ofglobal biogeochemical cycle. Changes in test morphologies of foraminifera through geologictime control mainly by genetic information. Through series of culture experiments, we cananswer whether or not these assumptions are true or false. Here, we give two examples.

1) Mg/Ca concentration in foraminiferal tests changes in proportion to temperature gradients.Currently, many of paleoceanographers use this proxy for reconstructing paleotemperature.However, there are several points before adopt this proxy to natural samples. For instance,we should select genera and species. Because, Mg/Ca values change from genera togenera. The value is also different from part to part within one specimen and even within onechamber. On the other side, this new results indicate that we can detect daily or seasonalchanges of water temperature using these facts.

2) Both DNA analyses and breeding experiments are another smart approaches forunderstanding either genotypic or ecophenotypic variations of foraminiferal test morphology.For instance, both breeding experiment and DNA analyses for genus Planoglabratella clearlyshow that both ecophenotypic and genotypic variations exist in morphological variations. Wecan easily establish new environmental proxies through these approaches.

Seasonal and interannual variability of coccolithophores fluxes andspecies composition in sediment traps off Cape Blanc (NW-Africa).

Köbrich, M.I. and Baumann, K.-H.

FB Geowissenschaften, Universität Bremen, Postfach 330440, 28334 [email protected], [email protected]

It is known that coccolithophores can be assigned to particular water masses or to photiczone characteristics and, therefore, species or whole assemblages can be used asoceanographical indicators. A prerequisite for palaeoceanographic studies or paleaeoclimaticreconstructions using coccolith assemblages is the under-stan-ding of the ecological affinitiesof extant species.

Coccolithophore flux variations in sediment traps of the time-series station CB (Cape Blanc),located at about 20°N 20°W, were recorded for the time interval from March 1988 toNovember 1991. The cup particle traps were deployed at 2200 to 3500 m below sea surface,and sampling intervals ranged from ten days to three weeks. Qualitative and quantitativeanalyses of the coccolithophores were performed with the scanning electron microscope

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(SEM). Each coccolith and coccosphere was counted and identified to the lowest taxonomiclevel as possible.

The downward fluxes of coccolithophores showed significant variations in speciescomposition during the four years period. Highest coccolith fluxes of 1158 x 107 coccoliths m-

2 d-1 occurred at the end of February 1991, whereas only of 9 x 107 coccoliths m-2 d-1 wererecorded in May 1991. The coccolithophore assemblages were dominated by Emilianiahuxleyi, the most ubiquitous species on earth, together with the deep-living speciesFlorisphaera profunda, and Gladiolithus flabellatus. At about the time of the coccolith fluxmaximum a distinct change in species composition occurred. In addition to the abovementioned taxa, species of Umbellosphaera and Syracosphaera also reached highabundances after the total coccolithophore flux maximum.

The presentation gives insight into the seasonal variation of coccolithophore export and theinfluencing abiotic factors. It focuses on the determination of seasonal variation in thecoccolithophore species composition, their relationship to the hydrographical conditions ofthe upwelling area, as well as their relationship to the overall carbonate flux.

Recent (Rose Bengal stained) benthic foraminifera from Portuguesemargin canyons

K.A. Koho (1), T.J. Kouwenhoven (1), G.J. van der Zwaan (1), H.C. de Stigter (2), T.C.E. vanWeering (2)

(1) Utrecht University, Faculty of Geosciences, the Netherlands, [email protected](2) Royal Netherlands Institute for Sea Research, the Netherlands

Submarine canyons are dynamic environments that transport and trap vast quantities ofsediment, nutrients and organic carbon. Excess 210Pb values in sediments from the NazaréCanyon are found to be an order of magnitude higher than in the adjacent shelf and slopeenvironment, reflecting increased particle settlement fluxes in the canyon. In addition, thesediment accumulation rates over a period of time are by far highest in the canyon and havehigh C-org values. The combination of these parameters together with the physicaldisturbance due to functioning of the canyon will result in an extraordinary and adaptedecosystem.

Preliminary results will be presented from a detailed quantitative analysis of living (RoseBengal stained) benthic foraminiferal assemblages from Nazaré and Lisbon-Setúbalcanyons, which are located on the Portuguese continental margin. These canyons have acomparable oceanographic setting, including narrow shelf, summer upwelling regime andexposure to southwesterly storms in winter. However, while the Lisbon-Setúbal canyons arefed by the rivers Sado and Tagus, the Nazaré canyon has no direct river influence.

The total standing stocks (TSS) appear to be highest at the head of each canyon and declinein general with depth. However, the axis of the Nazaré canyon appears to be nearly barren incontrast to Lisbon-Setúbal canyons. Nevertheless, in a previous study carried out at royalNIOZ van den Berg and de Stigter (data not published) found abundant foraminiferapopulations along the axis of the Nazaré canyon. Agglutinated taxa are present in greatnumbers at many locations and sometimes dominate the assemblages of the Portuguesemargin canyons. This is in contrast with previous canyon studies which revealed that theforaminifera assemblages in canyons off New Jersey and Gulf of Lions are dominated bycalcareous foraminifera species such as Uvigerina spp. and Bulimina spp..

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An overview of late Miocene benthic foraminiferal data from theMediterranean

Kouwenhoven. T.J. (1) and van der Zwaan, G.J. (1, 2)

(1) Department of Earth Sciences, Utrecht University, The Netherlands. [email protected](2) Department of Ecology / Biogeology, Radboud University Nijmegen, The [email protected]

Historically, it has proven problematic to derive reliable palaeoenvironmental informationfrom pre-Messinian Mediterranean sediments. Consequently, the sequence of eventspreceding the late Messinian evaporative phase, commonly referred to as the Messiniansalinity crisis (MSC) is still uncertain. Where integrated dating methods (bio-, cyclo-,magnetostratigraphy) allow us to place important bio-events within a well-constrained timeframe, the events themselves are still not fully resolved. A generally accepted scenario is thatseverance of the Betic and Rif Corridors (SE Spain and NW Morocco, respectively) isolatedthe Mediterranean more or less completely from the Atlantic in the course of the lateMiocene. Different stages in the Messinian restriction of the Mediterranean are tentativelycorrelated with uplift in different areas of the Rif Corridor. We will present an overview of dataderived from benthic foraminiferal faunas covering the late Tortonian and the Messinian up tothe start of the evaporative phase. Palaeoenvironmental reconstructions were made atseveral locations and at different depths of deposition, and together with data from othersources they allow us to develop a picture of the actual pre-crisis events.

Middle to Late Miocene fluctuations in the initial BenguelaUpwelling System revealed by coccolith assemblages (ODP Site1085A)

Krammer, R. (1), Baumann K.-H. (2) and Rüdiger Henrich (2)

(1) Research Center Ocean Margins, University of Bremen, Germany ([email protected])(2) Department of Geosciences, University of Bremen, Postfach 330440, 28334 Bremen,Germany

The Middle to Late Miocene is known as an interval of major changes in the climate system,such as the expansion of the Antarctic ice sheets, the cooling of surface and deep watermasses, as well as the start of the Isthmus of Panama (e.g., Zachos et al., 2001). Thesechanging boundary conditions had significant impacts on ocean circulation, nutrient supplyand, thus, on the productivity of the oceans. Previous investigations of the Miocene history ofthe upwelling off SW-Africa concluded that the onset of high productivity was at about 12 Ma(Diester-Haass et al., 2004).

We analysed coccolith data of ODP Site 1085 from the SE-Atlantic to document changes insurface-ocean circulation, upwelling initiation, and associated productivity. Our data showthat coccoliths constitute a significant part of the carbonate content. Highest numbers ofcoccoliths were observed during the intervals 9.9 to 9.7 and 8.7 to 8.0 Ma. These elevatednumbers of coccoliths may generally be linked to the initiation of upwelling at about 10 Ma inthe studied region. In contrast, diminished numbers of coccoliths, as in the interval 9.6 to 9.0Ma, probably characterise time intervals of weaker upwelling and thus a drastic decrease incoccolith contents of the sediments. Coccoliths account for more than half of the carbonate,with peak contribution up to 80 % at 8.8 Ma. Generally, a correlation between productivity inthe initiated upwelling and carbonate production by coccoliths seems reasonable.Diester-Haass, L., Meyers, P.A., Bickert, T., 2004. Carbonate crash and biogenic bloom in the Late

Miocene: Evidence from ODP Sites 1085, 1086, and 1087 in the Cape Basin,southeast AtlanticOcean. Paleoceanography, 19, PA 1007, doi: 10.1029/2003PA000933.

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Zachos, J., Pagani, M., Sloan, L., Thomas, E., Billups, K., 2001. Trends, rhythms, and aberrations inglobal climate 65 Ma to present. Science, 292, 686-693.

Stationarity of planktonic foraminifer niche since the last glacialmaximum

Kucera, M.

Institut für Geowissenschaften, Eberhard-Karls Universität Tübingen, Sigwartstrasse 10, DE-72076 Tübingen; Germany. [email protected]

All empirically calibrated microfossil paleoproxies, be it transfer functions or geochemicalsignals, rely on the assumption that the properties of modern species remained the same inthe past. This assumption is certainly valid for short periods of time, like centuries ormillennia, but on geological time-scales, its validity must be questioned. Species are notconstant through time and their ecological properties change. As a result, the validity ofempirical calibrations is always restricted to a limited part of the range of a given species. Asimilar limitation applies for the rage and variety of environmental conditions in the past:empirical calibrations are bound to the realm of ecological circumstances represented in thecalibration dataset. Paleoceanographers using microfossil-based proxies are thus faced witha fundamental problem: to what degree is a fossil estimate affected by the unquantifiable, yetomnipresent, effect of "no-analog” situations?

Using the recently compiled MARGO database of census counts of planktonic foraminiferassemblages, I have attempted to determine how significant the problem of "no-analog”situations is for the nearest Quaternary climatic extreme: the Last Glacial Maximum (LGM).Analysis of the MARGO database indicates that glacial foraminifer faunas occupied thesame, or a slightly smaller portion of the multivariate space defined by abundances ofmodern species. This implies that LGM oceans showed a similar range of environments asmodern oceans and that planktonic foraminifera responded to subsequent warming mainlyby expansion of their geographical ranges. I will also demonstrate that the "no-analog”problem is of subdued importance in LGM transfer function applications, compared touncertainties arising from the use of different computational techniques. The same approachcan be adopted from any other time slice in the past as an effective means to assess theextent of ecological difference between modern and fossil faunas.

Fatty acid analysis unravels the role of benthic foraminifera incarbon cycling within the Pakistan margin oxygen minimum zone

Larkin, K. E. (1), Gooday, A. J. (1), Pond, D. W. (2) and Bett, B. J. (1)

(1) DEEPSEAS Group, Southampton Oceanography Centre, Empress Dock, European Way,Southampton SO14 3ZH, U.K. [email protected](2) British Antarctic Survey, British Antarctic Survey, High Cross, Madingley Road,CAMBRIDGE, CB3 0ET, United Kingdom. [email protected].

Deep-Sea benthic environments provide key sites for carbon cycling, with complexinteractions occurring between the sediment biogeochemistry and infaunal organisms. InOxygen Minimum Zones (OMZ‚s), where dissolved oxygen concentration is < 0.5 ml l-1,hypoxia will influence the biogeochemical cycling of elements and the structure of benthiccommunites where it impinges on the continental margin. Foraminiferans are a majorcomponent of benthic biomass in OMZ‚s, as they display tolerance and adaptations to lowoxygen conditions. However, the role of foraminiferans in elemental cycling within OMZs isunclear. Fatty acid biomarkers are being used as a powerful tool to investigate the diets ofthis diverse group of protists across an OMZ on the Pakistan Margin, northeast Arabian Sea.At 300m, within the core of the OMZ (O2 < 0.1 ml l-1), our results indicate that individualforaminiferan species feed selectively. In situ and shipboard feeding experiments, using 13C

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labelled diatoms as an artificial food source, have enabled the tracking, using GC-MS, ofcarbon uptake into individual fatty acids of Uvigerina peregrina, the first time this has beenachieved in the case of a foraminiferan. This shallow infaunal calcareous species exhibited arapid response to the labile food source, suggesting that it is an important consumer oforganic carbon on the sea floor, especially in low oxygen environments such as the Pakistanmargin OMZ where it dominates the foraminiferal assemblage and macrofaunal andmegafaunal organisms are rare or absent. Previous studies have shown that the abundanceof Uvigerina peregrina is related to concentrations of organic carbon at the seafloor ratherthan to bottom-water oxygen concentrations. Nevertheless, its high population densities inmodern laminated sediments on the Pakistan Margin suggests that Uvigerina peregrinacould be used as an indicator of past fluctuations in the extent of the Arabian Sea OxygenMinimum Zone.

Coccolith evolution and stable isotopes during the Late Miocene /Early Pliocene Biogenic Bloom in the Eastern Equatorial Pacific

Lezius, J. and Kinkel, H.

Research Unit Ocean Gateways, Institute for Geosciences, University of Kiel, Ludewig-Meyn-Straße 10, 24118 Kiel, Germany; [email protected]

During the Late Miocene/Early Pliocene an event of unususal increase in the carbonateaccumulation rate has been observed in all ocean basins. This "Biogenic Bloom" ispronounced mainly due to enhanced coccolithophorid productivity and the presence of largercoccoliths, compared to younger intervals.

We investigate the coccolithophorid assemblage in ODP Site 1241 with respect to theirspecies composition, morphometry and stable isotopes. At this site the Biogenic Bloom isexpressed as a 5-fold increase in the carbonate accumulation rate, the sand fraction neverexceeds 8%, thus foraminifera are neglectable concerning the overall carbonate budgets.The coccolithophorid assemblage composition, dominated by small to mediumReticulofenestra, clearly shows enhanced productivity during the Biogenic Bloom interval. Onaverage the relative abundance of the lower photic zone species (Florisphaera profunda) islow, suggesting an increased nutrient supply to the upper photic zone, though we detect anincrease in this taxa and additionally in Sphenolithus and Discoaster indicating a decrease inproductivity at the end of the Biogenic Bloom. Here we observe a distinct floral shift at 6.3 Maand changed contribution to the total coccolith carbonate due to varying size portions ofcoccoliths. The decrease of coccoliths of the genus Reticulofenestra is closely following adistinct decrease in the stable-carbon isotope composition of the carbonate fine-fraction. Toevaluate whether the carbon isotope shift is real or reflects changes in coccolithophoridspecies composition (preclude species specific vital effects), comparisons are made of bulkfine fraction (<63µm, <20µm) and different sub-fractions representing differentcoccolithophorid species assemblages.

Dissolution as indicated by coccoliths in the Cariaco Basin,Venezuela

Mertens, K.N. and Louwye, S.

Research Unit Palaeontology, Department of Geology and Soil Science, Ghent University,S8, Krijgslaan 281, 9000 Gent, [email protected]

The Tropical regions are nowadays more and more actively implicated in Quaternary climateregulation. The aim of this study is to establish a reconstruction of the palaeoclimate in theCariaco Basin during the last 21 ka, using nannofossil fluctuations as proxies.

The Cariaco Basin is an anoxic pull-apart basin on the continental shelf of Venezuela. Theregion is under the influence of the migrating intertropical convergence zone (ITCZ) which is

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reflected in the light-dark coloured cycles in the sediment (varves). The question arose,whether these migrations are observable on a stadial/interstadial scale.

A high-resolution analysis of ODP-core 1002C demonstrated that increases in Emilianiahuxleyi go hand in hand with decreases of Gephyrocapsa oceanica and vice versa. Sinceecological models give no satisfactory explanations of this trend, one can only resort topinning down carbonate dissolution as the main cause. Moreover, since a wide range ofpreservation states is observed, and there is a clear regression with the rain ratio, it must bea case of supralysoclinal dissolution caused by decomposition of organic material.Dissolution of carbonate results in an enrichment of resistant Gephyrocapsa oceanica, incontrast to fragile Emiliania huxleyi. We propose a new dissolution index GEX based on theratio of relative abundances of these taxa. Dissolution was more intense during stadials,associated with decreased inorganic carbon loss in the water column.

Lower accumulations of coccoliths during anoxic settings, can be linked to reducedbiocalcification due to increased Dissolved Inorganic Carbon contents (DIC). Thesevariations in DIC are coupled to upwelling of Subtropical UnderWater (SUW), and linked toshifts of the ITCZ during precession-minima. There appear to be a clear asynchronicitybetween shifts observed in the equatorial region and the northern latitudes, and this suggestsa more active role in regulation of the thermohaline circulation in this region.

The new subfamily Starobogatovellinae (Foraminifera).

Mikhalevich, V.

Zoological Institute RAS; Universitetskaya nab.1, 199034, St. Petersburg, [email protected]

Following the customary approach when the shell wall composition was considered as themost important taxonomic feature Starobogatovella Mikhalevich, 1994 was initially placedinto the family Ammoscalariidae Mikhalevich, 1982. The septa between the chambers areorganic in this genus as well as in the Ammoscalaria Hoeglund, 1947. But their morphologydiffers significantly. Basing myself on the predominant significance of the morphologicalfeatures and supposing that the shell wall can change from the tectinous to the agglutinatedone independently in different phyletic lines Starobogatovella is separated here from theAmmoscalaria.

Order LITUOLIDA Lankester, 1885. Superfamily Lituoloidea de Blainville, 1827. Lituolidaede Blainville, 1827. Starobogatovellinae Mikhalevich subfam. nov. Type genus:Starobogatovella Mikhalevich, 1994.

Test with evolute planospirally coiled part and very short, narrow and fragile rectilinearuncoiled part rounded in section, chambers subcylindrical, very slowly increasing in size, upto 10 -16 in the last whorl; wall agglutinated, with tectinous inner septa; aperture - open endof the last tubular chamber equal in diameter to chamber lumen, apertures of the precedingchambers - small openings in the middle of tectinous septa having a short tectinous collar.Holocene.

Remarks. This subfamily differs from Ammoscalariinae in the character of the test: evoluterather than involute coiled part with multiple whorls, short and cylindrical rather than welldeveloped flattened rectilinear part, and in the form of the chambers, from the subfamiliesAmmobaculitinae and Lituolinae - in the character of the chambers bearing the tubularfeatures, in the weak development of the uncoiled part and in the fully evolute initial part. Itdiffers from all the other lituolids in its tectinous inner septa. This subfamily has anintermediate character between Lituotubidae and Lituolidae.

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Core top calibrations of Boron isotope paleo-pH proxy

Ni, Y. (1), Foster, G. (1), Haley, B. (1), Bailey, T. (2) and Elliott, T. (1)

(1) Department of Earth Sciences, University of Bristol, Wills Memorial Building, QueensRoad, BS8 1RJ, Bristol, U.K.(2) National Museums and Galleries of Wales, Cathays Park, CF10 3NP, Cardiff, U.K.

The use of boron isotopes to look at palaeo-ocean pH and ultimately pCO2 has greatpotential for constraining climate reconstructions. However, there have recently beendiscussions concerning the accuracy of the technique. Hence we have developed acompletely new methodology to measure B isotopes and use this approach to further groundtruth the boron isotope proxy by examining 5 common species of planktonic foraminifera incore top samples from two tropical equatorial sites (ODP 806B, C Pacific; ODP 664CAtlantic). Our new total evaporation method of boron isotope analyses enables the analysisof relatively small numbers of forams (as few as 10 individuals), and the combination of thesemeasurements with elemental analyses on the same dissolutions, to examine potentialspecies and size fraction effects on the measured δ11B. In general we found no systematicchange in δ11B with sample size for the surface dwelling species, indicting that physiologicalprocesses have no clear influence on the δ11B in the planktonic foraminiferal shells. The δ11Bfor both cores is estimated to be 24 ± 1‰ for the surface dwelling species, G. sacculifer andG. ruber. For deeper dwelling species in core 664C we find that δ11B decreases with depthhabitat as would be expected from modern seawater pH profiles; namely 20 ± 1‰ for N.dutertrei and G. tumida. For G .truncatulinoides the δ11B decreases from 19 ‰ to 17‰ withincreasing size fractions, which is consistent with changes of habitat depth during their lifecycle. For the same samples Mg/Ca, U/Ca ratios increase and Sr/Ca ratios decrease withincreasing shell size compatible with the hypothesis that smaller individuals calcifying fasterthan larger individuals and larger individuals form calcite that more closely reflects seawatertemperature and composition. We stress however that, in contrast to previously publishedstudies we find no such effect for the boron isotope proxy.

Palaeomagnetic and Planktonic foraminiferal biostratigraphy of aPlio-Pleistocene section, Rhodes (Greece)

Nielsen, K. S. S.

Geological Institute, Universtity of Copenhagen, Øster Voldgade 10, DK-1350 Copenhagen,Denmark; [email protected]

The Island of Rhodes makes up the easternmost part of the Aegean Arch, located near theTurkish mainland, in the Eastern Mediterranean Sea. The Tsambika profile is located on theroad to Tsambika Beach, approximately 25 km from the centre of Rhodes City at thesoutheastern coast of the Island. The investigated section consists of 40 m of marinesediment (limestone, silt/clay). Both the foraminiferal and palaeomagnetic data suggest thatthe section is of Late Plio-Pleistocene age.

A total of 60 planktonic species have been recorded. More than ten of those species havenot previously been recorded in the Mediterranean Plio-Pleiostocene.The results show that most species which have an FAD/LAD, near the Plio-Pleistoceneboundary in the Vrica section are diachronous when compared to the Tsambika section. Theonly four possible exceptions are the FAD of G. crassaformis, B. praepumilio, B. riedeli andN. eggeri (dutertrei?). However, neither B. praepumilio nor B. riedeli have been observed inthe Vrica section. The FAD of N. eggeri in the Tsambika section and the FAD of N. dutertreiin the Vrica section seems to be synchronous but the taxonomical uncertainty regardingthese species seem to exclude these as marker species.

Further, the coiling of N. parchyderma is dextral throughout the Tsambika profile whereas thespecimens observed in the Vrica section are sinistral near the Plio-Pleistocene boundary.

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Also the benthic foraminifera Hyalina baltica has been recorded, but the FAD of this speciespredates the Plio-Pleistocene boundary in the Tsambika section as indicated by thepaleomagnetic data. It is concluded that it is not possible to correlate between the Tsambikaand the Vrica sections based on foraminiferal biostratigraphy.

Novel application of MTT-reduction: a viability assay for benthicforaminifera

de Nooijer, L.J.(1), Duijnstee, I.A.P.(1,2) and van der Zwaan, G.J.(1,2)

(1) Department of Stratigraphy and Paleontology, Faculty of Geosciences, Utrecht UniversityBudapestlaan 4, 3584 CD Utrecht, The Netherlands. [email protected](2) Department of Biogeology, Faculty of Sciences, Radboud University, Toernooiveld 1,6525 ED Nijmegen, The Netherlands.

Studies on living foraminifera commonly involve staining samples with Rose Bengal (RB) todistinguish living from dead individuals. Since RB does stain individuals that have diedrecently and are not yet fully decayed, foraminiferal communities seem larger than theyactually are. We present a new viability assay based on the reduction of MTT by enzymes inliving foraminifera. The tetrazolium salt MTT is converted from a yellow, soluble form to ared/purple crystal. Living individuals convert MTT slowly and become stained within 24hours. Dead foraminifers, despite keeping their enzymatic activity for several days, yield adifferent coloration from stained living foraminifers, making the identification of false positivespossible.

Observation of a spring bloom at Kiel Bight, depositional eventsand reaction of the benthic foraminiferal community

Numberger, L. (1), von Bröckel K. (1), Schönfeld, J. (1) and Spindler, M. (2)

(1) Leibniz-Institute of Marine Science IFM-GEOMAR, Wischhofstr. 1-3, D-24148 Kiel;Germany. [email protected](2) Institut für Polarökologie, Wischhofstr. 1-3, D-24148 Kiel; Germany

A spring bloom and the benthic foraminiferal response were investigated between Januaryand July 2004 at Kiel Bight, Western Baltic Sea (54°32`N and 10°02`E, 23,5 m water depth).The purpose was to ascertain the correlation between production and deposition ofphytoplankton and the reaction of the benthic foraminiferal community. Three depositionalevents of organic detritus into the surface sediment were recorded. Food preferences wereobserved for Reophax dentaliniformis and Elphidium excavatum clavatum with reference totheir nutrition dynamics. The comparision between the actual investigation and earlier studiesfrom the 1970´ies showed long term changes of living benthic foraminiferal communities. Achange in surface sediment texture and salinity of near bottom water was also recognised.Reproduction of Elphidium e. clavatum was stimulated by an increased availability of foodparticles. The growth and reproduction cycle of Elphidium e. clavatum lasted 2 to 3 weeksonly. The results revealed a similar timescale of benthic pelagic coupling in a shallow-waterenviroment as compared to the deep sea.

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Ecology and stable isotopes of living benthic foraminifera atdifferent methane seeps (Alaskan margin, California margin, Gulf ofCalifornia): Implications for the fossil record

Pérez, M. E. (1), Rathburn, A. E. (2), Adamic, J. F. (2), Martin, J. B. (3), Gieskes, J. (4),Ziebis, W. (5), Herguera, J.C. (6), Paull, C. (7)

(1) Palaeontology Dept., The Natural History Museum, Cromwell Road, London, SW7 5BD,UK. [email protected](2) Geography, Geology, and Anthropology, Indiana State Univ., Science Building 159, TerreHaute, IN 47809(3) Geological Science, Univ. of Florida, Box 112120, Gainesville, FL 32611(4) Integrative Oceanography Division, Scripps Institution of Oceanography, 9500 GilmanDrive, La Jolla, CA 92093-0236(5) Biological Sciences Department, Univ. of Southern California, Los Angeles, CA 90089(6) CICESE, Km 107 Carretera Tijuana-Ensenada, Ensenada, 22860 Mexico(7) Monterey Bay Aquarium Research Institute, 7700 Sandholdt Road, Moss Landing, CA95039-9644

Despite an increasing number of foraminiferal studies at methane seeps, our knowledge oftheir ecology and isotopic composition is poor and the use of benthic foraminifera asindicators of methane release in the past is still in debate. A previously unknown methaneseep was discovered in July 2004 during an extensive exploration of the seafloor with ROVJason II along the Aleutian margin off Unimak Island. This seep has many characteristics ofmethane seeps elsewhere including sulfide-oxidizing fauna (Calyptogena clams andpogonophorans) and authigentic carbonate minerals cementing detrital sediments. But incontrast to other methane seeps, pore waters of this seep show little evidence of methaneoxidation (e.g., increased sulfide and alkalinity concentrations).

Here we compare the species distributions and isotopic composition patterns of living benthicforaminifera (rose Bengal stained) of this newly discovered seep with those from seeps thatwe have previously studied in Monterey Bay (California) and Guaymas Basin (Gulf ofCalifornia) in order to gain insight into how different seep types affect foraminiferalassemblages and the geochemistry of their test.

Preliminary data suggest that in general foraminiferal abundance is lower in methane-influenced sites than in the sites characterized by low methane discharge. The foraminiferalassemblage in the seeps from Monterey Bay and Guaymas Basin are dominated bycalcareous species (Uvigerina peregrina, Bulimina mexicana, Globobulimina pacifica,Epistominella pacifica), whereas the assemblage in the Aleutian margin seep is dominatedby agglutinated taxa. Of special interest is the occurrence of numerous specimens ofCibicidoides wuellerstorfi attached to the pogonophoran tubes associated with this seep.Carbon isotope values of living benthic foraminifera at all seeps are not much lower thanthose observed in non-seep environments. These data question the extent to which strongisotopically-light δ13C signals in the geological record are primary or diagenetic features.

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Morphometrics of the planktic foraminifers G. truncatulinoides andG. ruber: Evolution and ecology affect the response to Pleistoceneclimatic variability

Renaud, S. (1) and Schmidt, D.N. (2)

(1) UMR 5125 CNRS UCB Lyon 1, Campus de la Doua, 69622 Villeurbanne, [email protected](2) Department of Earth Sciences, University of Bristol, Bristol BS8 1RJUnited Kingdom. [email protected]

The morphometric variation of two species of planktic foraminifers was investigated in a corelocated in the subtropical gyre of the SE Atlantic covering the last 1 Million years. Themorphology of the foraminifers was quantified using a Fourier analysis of their outline in twoorthogonal views, size of the test, and coiling direction (for G. truncatulinoides). Both speciesappeared to be structured in morphotypes and/or cryptic species with presumably differentecological habits. The morphological variations observed through time therefore combinemixing of the different morphotypes in various proportions depending on the environmentalcontext, and a potential long-term evolution.

The deep dwelling G. truncatulinoides showed a strong test-shape / climate relationship overthe last 140 kyr, whereas no clear signal can be found prior to that during the last 1 Ma.Molecular evidences show that this taxon radiated 120-170 kyr ago into four clades with eachspecific environmental preferences. This habitat specialisation could be the prerequisite forthe test-shape / climate relationship observed during the last 140 kyr, since this relationshipseems to be related to the mixing of the different clades with specific morphologies. Beforethe radiation event, G. truncatulinoides ancestor clade responded to the climatic changes ina non-analogous way compared to the post-140 kyr condition. Its response may include both,long-term evolution and a plastic response initiating the differentiation and specialisation intothe four modern clades.

G. ruber shows a mixture of three morphotypes. The relative frequency of each morphotypeis related to glacial-interglacial changes over the 1-myr period. This result shows that theclimatic variability in the subtropical gyre was sufficient to cause a shape response of theplanktic foraminifer since this shape response mainly involved habitat tracking by establishedmorphotypes: this process does not involve long-term evolution and allows a fast response tothe Pleistocene climatic variability.

The comparison of the two species shows that the ability of a species to respond to rapidenvironmental fluctuations depends on its evolutionary history. When clades with differentecological habits are established within the taxon, the response of the foraminifer to climaticchanges occurs through habitat tracking, a process that leads to a good relationship betweenmorphometric data and paleoenvironmental proxies. When long-term evolution is thedominant process, however, deciphering the relationship between climate and foraminifershape variation becomes more intricate.

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Benthic Foraminifera from the El Buho Canyon and Fan (LateMiocene of the Tabernas Basin, SE Spain).Rogerson, M. (1), Kouwenhoven, T.J. (1), van der Zwaan, G.J. (1,2), O’Neill, B.J. (3), van derZwan, C.J. (1,4), Postma, G. (1), Kleverlaan, K. (5) and Tijbosch, H.J. (1)

(1) Faculty of Earth Sciences, University of Utrecht, 3584 CD Utrecht, Netherlands.(2) Faculty of Biology, University of Nijmegen, 6525 ED, Netherlands.(3) Shell International Exploration and Production plc, New Orleans, Louisiana, 70151-1510,USA.(4) Shell International Exploration and Production plc, 2280 AB, Rijkswijk, Netherlands.(5) Zeeburgerdijk 585, 1095 AE Amsterdam, Netherlands/The sedimentology andmicropalaeontology of an exhumed Miocene age canyon and fan system from the TabernasBasin (SE. Spain) has been investigated. Four sections from the El Buho canyonencompassing proximal canyon, distal canyon and adjacent slope environments have beenlogged on a centimeter scale and the 150-595_m size range of 174 samples have beenexamined for their benthic foraminiferal content. Two further sections from the time-equivalent fan have also been investigated, and benthic foraminiferal census data has beencollected for a further 28 samples. The assemblages revealed are similar across all of theenvironments and individuals of Genus Cibicidoides (esp. C. dutemplei) generally dominate.However, several taxa show strong associations with a particular sub-facies.

Agglutinated taxa generally show a strong preference for the extra-canyon environments, asdo several calcareous taxa (Cassidulina obtusa, Uvigerina rutila and Cibicidoidesrobertsonianus). These taxa are systematically excluded along the gradient of increasingsediment flow activity within the canyon and fan system, resulting in a declining diversity ofthe assemblage in increasingly high energy environments. Minimum diversity is achieved inbarren samples recovered from the sand-dominated deposits of the proximal canyon andcanyon axis. A similar trend is found within foraminiferal density data.

Presence of Cassidulina laevigata near-exclusively within energy minimum zones within thecanyon indicates a strong preference of this species to environments that are sheltered fromdirect disturbance, but that have differing environmental characteristics to the open slope.This most likely reflects elevated food supply within the canyon. 9 samples, mainly from thefan (5), display an assemblage dominated by Genus Globobulimina (up to 55%). Theseassemblages are characteristic of environments that are oxygen-limited, and thus probablyindicate periods / locations where the food supply was sufficiently enhanced to promotedysoxia.

The presence of good presence/absence indicators and unique assemblages withinparticular environments allows delineation of slope, canyon and fan environments withcertainty within the Tabernas Basin by micropaleontology alone. Environmentally sensitivewhole-assemblage indices give additional insight into disturbance periodicity, and provide amethod by which further environments within the canyon can potentially be recognized.Benthic foraminiferal assemblage data therefore hold significant potential for thedevelopment of predictive tools for delineating environment of deposition in analogousmarine systems.

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Cenomanian Foraminifera of Eastern Bavaria

Schenk, B. (1), Kling, M. (2) and Rohrmüller, J. (3)

(1) Department für Geo- und Umweltwissenschaften, Sektion Paläontologie, Richard-Wagner-Str. 10 / II, 80333 München. [email protected](2) Department für Geo- und Umweltwissenschaften, Sektion Mineralogie, Petrologie undGeochemie, Theresienstr. 41, 80333 München. [email protected](3) Bayerisches Geologisches Landesamt, Außenstelle Marktredwitz, Leopoldstr. 30, 95615Marktredwitz. [email protected]

The research area is situated near the town of Roding/Germany, 60 km east of Regensburg,at the southern border of the Bodenwöhr Basin, a half-graben structure filled with clasticsediments of upper cretaceous age. This half-graben structure stretches about 70 km inWNW-ESE direction inside the Bavarian Forest, roughly following the "Pfahl" Shear Zoneand is surrounded by metamorphic and magmatic rocks of variscian age. The cretaceoussedimets are usually flat lying or dip gently to the north, the maximum thickness of thesediments reaches several 100 meters.

The two occurences where the investigated samples were taken, show a differentstratigraphic profile. The quarry at Grub/Roding shows a black shale with small pebbels atthe base. It is overlied by glauconite bearing coarse sandstone and a greyish-blue sandymarl. Above are glauconite bearing coarse sandstone and marl. Then follows a fine grainedcarbonaceous sandstone, the Reinhausen-Formation. The abandonend quarry atObertrübenbach shows a conglomerate horizon, overlied by a glauconite bearingcarbonaceous sandstone and a sandy marl. Again the fine grained sandstones of theReinhausen-Formation lie on top of the sequence.

19 sediment samples (15 from Grub, 4 from Obertrübenbach) were wet-sieved, and thespecimens were picked out from the > 63 µm residue. Three samples contain no foraminiferaat all. Because of abrasion the specimens sometimes could not be clearly determinated. Allsamples show clear marine settings (e.g. fish teeth, radiolaria, sponge spiculae) without anybrackish influence. Surprisingly no single planctonic specimen have been found, either.Agglutinanted foraminifera are also very rare. These factors indicate an nearshoreenvironment (Sen Gupta, B. K., 1999). The comparison of the species with Bohemian andMoravian ones (e.g. Hercogova, J. 1974, Hanzliková, E. 1970) indicate a cenomanian agefor the two locations. Even upper cenomanian in the case of the quarry of Grub/Roding.Hanzliková, E. (1972): Carpathian Upper Cretaceous Foraminiferida of Moravia (Turonian -

Maastrichtian). Rozpravy Ústredniho ústavu geologického, 39: 5-160.

Hercogova, J. (1974): Foraminifers from the Cenomanian of the Bohemian Massif. SbornikGeologickyoh ved, paleontologie,16: 69-103.

Sen Gupta, B. K. [Hrsg.]: Modern Foraminifera: 3 - 6; Dordrecht (Kluwer Academic Publishers).

Automated particle analysis in micropalaeontology

Schiebel, R.(1), Bollmann, J.(2) and Thierstein H.R.(2)

(1) School of Earth & Ocean Science, Southampton Oceanography Centre, European Way,Southampton SO14 3ZH, UK. [email protected](2) Geological Institute, Swiss Federal Institute of Technology Zurich, Sonneggstrasse 5,8092 Zurich, Switzerland

Analyses of the abundance and assemblage composition of microplankton, and of thechemical and stable isotopic composition of their shells, have been among the mostsuccessful methods in palaeoceanography and palaeoclimatology. Micropalaeontologicalprojects are often limited by the number of samples that can be processed and analyzedwithin a certain time. For statistical reasons faunal counts have to include at least 300specimens (normal case). For stable isotope analyses and for C-14-measurements at least~10 and 800 medium sized planktic foraminifers are needed.

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The manual collection of statistically significant quantities of unbiased, reproduciblemicrofossil data is time consuming. Consequently, automated microfossil analysis andspecies recognition has been a long-standing goal in micropaleontology. Our target is tospeed up and standardize palaeoceanographic data acquisition using an automated incidentmicroscope for obtaining digital images, and artificial neural networks (ANNs) foridentification of particles, groups and species.

Identification does critically depend on pre-processing of the images and is carried out on PCcomputers by the Windows®-based artificial neural network software package COGNIS. Allsuccessful neural network runs were carried out with a similar setup, using a convolutional 5-layer network (layer 1 and 3: convolutional, 8 layers, 5x5/4; layer 2 and 4 sub-sampling, 2x2;one output layer), which will help to significantly speed up palaeoceanographic dataacquisition. Average recognition rate of 75% (max. 88%) for 6 taxa (N. dutertrei, N.pachyderma dextral, N. pachyderma sinistral, G. inflata, G. menardii/tumida group, O.universa, represented by 50 images each for 20 classes (separation of spiral and umbilicalviews, and of sinistral and dextral forms). Our investigation indicates that neural networkshold great potential for the automated classification of planktic foraminifers and offers newperspectives in micropalaeontology, palaeoceanography and palaeoclimatology.Bollmann, J., Quinn, P.S., Vela, M., Brabec, B.,Brechner, S., Cortés, M.Y., Hilbrecht, H., Schmidt,

D.N., Schiebel, R., and Thierstein, H.R., 2004. Automated particle analysis: Calcareousmicrofossils. In: Francus, P. (Editor), Image Analysis, Sediments and Paleoenvironments. KluwerAcademic Publishers, Dordrecht, The Netherlands.

Neogene origin of the modern pelagic niche and its consequencesfor pelagic carbonate production

Schmidt, D. N. (1) and Kucera, M. (2)

(1) Department of Earth Science, Wills Memorial Building, University of Bristol, BS8 1RJ,Bristol, UK [email protected](2) Institut für Geowissenschaften, Sigwartstr. 10, 72076 Tübingen, [email protected]

Biologically mediated fluxes of carbonate between the upper and deep ocean depend oncalcification of marine microplankton and lead, over geological time, to massiveaccumulations of calcite in ocean sediments. Changes in the size of pelagic carbonateproducers influence the amount of material exported to the deep ocean. The size ofcarbonate producers is known to have varied considerably over geological time (Young,1990; Schmidt et al., 2004) with as yet unquantified implications for modelling of pelagicexport production. Here we investigate the relationship between tectonic/oceanographicchanges in the Neogene, plankton size and carbonate accumulation rates.

We have analysed foraminiferal size record and carbonate accumulation patterns in four mid-and low latitude Neogene sites at an average resolution of 70 kyrs and compared it withexisting data on size in calcareous nannoplankton and radiolaria. Carbonate preservation isgood during the last 10 Ma and hence does not influence size or accumulation rates. Orresults indicate that the dramatic size increase in foraminiferal assemblages is limited to theoligotrophic tropical environments and does not occur in temperate of upwelling areas. Thechanges in size do not reflect evolution of new, larger species, but they affect existinglineages.

Sand fraction accumulation rate, representing production of planktonic foraminifer shells,have doubled in the last 10 Ma with the largest change between 4-3 Ma in both tropics andmid latitudes. At the same time, the total carbonate accumulation has decreased.Furthermore, during the Neogene, large forms of coccolithophorids disappeared (Young,1990; Knappertsbusch et al., 1997). As a consequence, the contribution of foraminifera topelagic carbonate production has rocketed from 20% in the mid-Miocene to about 50%today. The similarity in the timing of the effective closure of the circum-tropical seaways andevolution of unprecedented large sizes among foraminifera suggest that this novel tectonic

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constellation has had a profound effect on the pelagic niche and on pelagic carbonateproduction.Knappertsbusch, M., Cortes, M.Y., Thierstein, H.R., 1997. Morphologic variability of the

coccolithophorid Calcidiscus leptoporus in the plankton, surface sediments and from the EarlyPleistocene. Marine Micropaleontology, 30: 293-317.

Schmidt, D.N., Thierstein, H.R., Bollmann, J., Schiebel, R., 2004. Abiotic Forcing of Plankton Evolutionin the Cenozoic. Science, 303: 207-210.

Young, J.R., 1990. Size variation of Neogene Reticulofenestra coccoliths from Indian Ocean DSDPcores. Journal of Micropalaeontology, 9: 71-86.

Benthic foraminifera from Deep-Water Coral Mounds in thePorcupine Seabight, NE Atlantic.

Schönfeld, J., Dullo, W.-Chr., Linke, P., Pfannkuche, O. and Rüggeberg, A.

Leibniz-Institute of Marine Sciences IFM-GEOMAR, Wischhofstrasse 1-3, 24148 Kiel;Germany. [email protected]

Cold-water coral ecosystems on mound-alike structures are common on the upper slope ofthe northwestern European continental margin. These ecosystems are generallycharacterized by a high diversity and population density in a strong hydrodynamicenvironment. Distribution and ecology of foraminifera from coral mounds are studied in theEU-funded HERMES programme (Hotspot Ecosystems Research on the Margins ofEuropean Seas). The foraminiferal associations are dominated by epibenthic species. Theirproportion and the diversity of the total assemblage decreases while the standing stockincreases with distance to the carbonate mounds. Benthic colonisation experiments weredeployed for 107 days with a deep-sea observatory (GEOMAR Modular Lander) in a coralthicket on top of Galway Mound, Porcupine Seabight. The observatory recorded physical andbiological parameters in order to assess the environmental dynamics. The colonisationexperiment comprised a variety of natural hard and soft substrates mounted to the footplatesof the lander. Hard substrates as ferrigenous sandstones, basalts, and coral fragments werecolonised by at least one specimen per object, but PVC and steel construction parts wererecruited as well. The epizoans concentrate at 20 to 30 cm immediately above the coralthicket. Average current velocities are comparatively low at this level. Newly recruitedforaminifera are Discanomalina coronata, Planulina ariminensis, Discanomalinasemipunctata, Epistominella rugosa, Cibicides lobatulus and others. This epibenthicassemblage is typical for deep high-energy environments in the northeastern Atlantic, and ithas been recorded in sediment cores from this area. Most foraminiferal specimes werealready of adult size. Thus, their rapid growth during three months or less necessitates a re-evaluation of growth-dependant processes, in particular the incorporation of stable isotopicand geochemical signals, which were hitherto referred to hydrographic annual averagevalues. In situ experiments in the deep-sea are a promising approach for proxy calibration inrelation to monitored environmental factors.

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Benthic foraminifera from the oxygen minimum zone of thePakistan continental margin - a proxy of bottom water oxygenation

Schumacher, S.(1); Jorissen, F.J.(1); Dissard, D.(2); Gooday, A.J.(3) and Larkin, K.(3)

(1) Laboratory of Recent and Fossil Bio-Indicators, University of Angers, 2 Bd Lavoisier,49045 Angers Cedex, France. [email protected](2) Foundation Alfred Wegener Institute for Polar and Marine Research, Am Handelshafen12, 27570 Bremerhaven, Germany(3) Southampton Oceanography Centre, DEEPSEAS Benthic Biology Group, Empress Dock,European Way, Southampton SO14 3ZH, United Kingdom

Live (Rose Bengal stained) and dead benthic foraminifera (hard-shelled species only)communities from the oxygen minimum zone (OMZ) of the Pakistan Continental margin havebeen studied to determine the correlation between faunal distribution and oxygenation ofbottom and pore water. Samples were taken from 133 m water depth down to 1800 m waterdepth in spring before the southwest monsoon and in autumn immediately following thenortheast monsoon.

In the upper part of the OMZ, between 150 and 500 m water depth where bottom wateroxygen concentrations are <0.2 ml/l, living foraminifera are frequent. The live and deadfaunas are dominated by few calcareous species, diversities (Shannon-Weaver index andFischer Alpha index) are low. The fauna contains significant numbers "endemic” species andrare numbers of typical deep-infaunal species. In the lower part of the OMZ (600-1200 m) theliving fauna of the fraction larger than 150 micron is much poorer and is dominated byarrenaceous foraminifera, the smaller fraction contains significant numbers of livingindividuals including also a large number of calcareous species. Diversities of live and deadfaunas are higher and the faunas inhabit more cosmopolitan and deep infaunal species.Everywhere in the OMZ live foraminiferal faunas are limited to the uppermost centimetre,whereas above and below the OMZ benthic foraminifera occur also deeper in the sediment.

The relation between benthic foraminiferal faunas and oxygen concentrations in the OMZ iscomplex, because of the absence of deep-infaunal species and the abundance of "endemic”species in the upper part of the OMZ. Therefore, proxies based on the abundance of deep-infaunal taxa give poor results. We will present an ameliorated version of a previousdescribed proxy for bottom water oxygenation.

Comparison between morphological and genetic species conceptsin the genera Cibicides and Uvigerina (calcareous benthicforaminifera)

Schweizer, M. (1,2), Pawlowski, J. (2), Kouwenhoven, T.J. (1) and van der Zwaan, G.J. (1, 3)

(1) Department of Earth Sciences, Utrecht University, Netherlands; [email protected](2) Department of Zoology and Animal Biology, University of Geneva, Switzerland(3) Department of Biogeology, Radboud University Nijmegen, Netherlands

Cibicides and Uvigerina are cosmopolitan genera of calcareous benthic foraminifera, whichare widely used for isotopic analyses and palaeoenvironment studies. In spite of the fact thatthey are important proxies, their evolutionary trends are not well known. The different speciesare distinguished on morphological criteria, but it is not always easy to ascertain whethermorphotypes belong to the same, or to different species.

The 11 species of Cibicides we study are classified, on morphological grounds, in 5 differentgenera belonging to 3 different superfamilies. However, the fact that intermediatemorphotypes are observed between these species shows they certainly belong all to thesame genus, Cibicides. For Uvigerina, the situation is less complex. The 11 studied speciesare classified within the same genus.

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The first molecular results based on two fragments, of 1000 nucleotides each, of the smallsubunit of ribosomal DNA (SSU rDNA) show that the six species of Cibicides we obtainedform a monophyletic group. The status of the different morphospecies is confirmed in certaincases, but not in others. One fragment of 1000 nucleotides of the SSU rDNA was employedto investigate the phylogeny of Uvigerina. Two species belonging to closely related genera,Trifarina earlandi and Rectuvigerina phlegeri, are closer to U. peregrina than U.mediterranean and U. elongatastriata. This suggests a revision of the taxonomic status ofUvigerina is needed. Another fragment of rDNA (the ITS) was studied to explore the variationinside one morphologically highly variable population of U. peregrina: the genetic variabilitywas rather low. These first molecular results will provide a different point of view in theresolution of the taxonomic problems encountered in the classification of Cibicides andUvigerina.

The Stability of Eocene Warmth and Carbon Cycling - New Recordsin Foraminiferal Calcite from Demerara Rise

Sexton P. F. (1), Wilson P. A. (1) and Norris, R. D. (2)

(1) School of Ocean & Earth Science, Southampton Oceanography Centre, European Way,Southampton, SO14 3ZH, UK. [email protected], [email protected].(2) Geosciences Research Division, Scripps Institution of Oceanography, MS-0244, La Jolla,CA 92093-0244, USA. [email protected].

Reconstructions of Early Cenozoic climates based on both marine and terrestrialgeochemical and fossil evidence suggest that the Eocene was the last interval of acuteglobal warmth. Yet virtually nothing is known of the magnitude and stability of Eoceneclimatic warmth and carbon cycle behaviour on anything but a long-term (multi-Myr)timescale. Our dearth of knowledge arises largely from a lack of appropriate deep seasections on which to work. Globally, deep sea sedimentary sections through the Eocene areplagued by recovery problems associated with widespread chert deposition, spot coringassociated with earlier Deep Sea Drilling Project drilling strategies, condensation horizons,hiatuses spanning multiple biozones and poor preservation of carbonate microfossils. This isparticularly true across the lower/middle Eocene boundary which is represented in the deepocean drill sections essentially by a global ~1 to 2 Myr-long hiatus.

Recently, Ocean Drilling Program (ODP) Leg 207 ("Demarara Rise: Equatorial Cretaceousand Palaeogene Palaeoceanographic Transect, Western Atlantic") recovered lower andmiddle Eocene deep ocean sediments (incl. a complete lower/middle Eocene boundary).Here we present new stable isotope records using planktic and benthic foraminiferal calcitefrom ODP Sites 1258 and 1260 with excellent age control to improve constraints on Eoceneclimatic evolution from the 'Early Eocene Climatic Optimum' through the so-called middleEocene 'doubthouse' interval.

Our ~100 kyr resolution record from the early to middle Eocene (~53 to 40 Ma) yields stableisotope values with consistent interspecies offsets among Demarara Rise benthicforaminifera. These data, in addition to pilot Mg/Ca data, document the long term climaticcooling following the Early Eocene Climatic Optimum and provide clear support for atemporary reversal (~44-42 Ma) in this trend of climatic deterioration.

Our ~6 kyr resolution records for the early to middle Eocene (~50 to 45 Ma) reveal highamplitude stable isotope excursions (~1 per mil) across the early/middle Eocene boundary,indicating significant instability in Earth's climate and carbon cycle during the transition out ofearly Eocene 'greenhouse' warmth.

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Multidisciplinary palaeoecology of Upper Maastrichtian chalks inthe Danish Central Graben – record of a sea-level lowstand.

Sheldon, E. (1), Lassen, S. (1), Rasmussen, J. A.(2) and Schiøler, P (1).

(1) Geological Survey of Denmark and Greenland (GEUS), Øster Voldgade 10, DK-1350,Copenhagen K, Denmark. [email protected](2) Geological Museum, Øster Voldgade 5-7, DK-1350, Copenhagen K, Denmark

The most important hydrocarbon reservoirs in the Danish sector of the North Sea are UpperCretaceous –Paleocene chalks. Effective production from existing fields and exploration inthe future will not only be increasingly dependent on an improved high-resolution chalkstratigraphy, but also on an understanding of the processes that create variations in reservoirparameters within the chalks.

Integration of nannofossil, foraminiferal and dinoflagellate biostratigraphy with stable isotopechemostratigraphy and sedimentology has resulted in detailed palaeoecologicalinterpretation of the Upper Maastrichtian chalks of 2 wells from the Danish Central Graben.

Based on evidence from this multidisciplinary study, two contrasting oceanographic systemsare thought to have been in operation in the Late Maastrichtian in this area. In the lower partof the cored sections, a cool water, oligotrophic stable system prone to stratification isinferred. A gradual fall in sea level is suggested to have proceeded resulting in thebreakdown of this stable environment, and culminating with a sea–level lowstand. A moredynamic setting incorporating warm water influx, sea-level changes and variable productivityfollowed almost to the end of the Maastrichtian.

Of particular interest to the hydrocarbon industry is the afore-mentioned lowstand levelrecorded immediately following the breakdown of the stable oceanographic system, justabove the bases of the UC20d nannofossil and the P. grallator dinoflagellate zones. Thislowstand event correlates precisely with the most important reservoir unit within the DanishCentral Graben, the M1b1 reservoir unit of the Dan Field.

Gromiid protozoans in the deep sea

Aranda da Silva, A. (1), Gooday, A.J. (1), Cedhagen, T. (2), Cornelius, N. (1) and J.Pawlowski (3)

(1) Southampton Oceanography Centre, Empress Dock, European Way, SouthamptonSO14 3ZH, UK. [email protected](2) Department of Marine Ecology, University of Aarhus, Finlandsgade 14, 8200 Aarhus N,Denmark. [email protected](3) Department of Zoology and Animal Biology, University of Geneva, 30 Quai Ernest-Ansermet, 1211 Geneva 4, Switzerland

Until recently, gromiids (large testate protists closely related to the Foraminifera) were knownfrom a single morphospecies (Gromia oviformis – probably a complex of cryptic species)found in coastal habitats around the world. However, recent campaigns on the Oman andPakistan margins of the Arabian Sea (1994, 2002, 2003) have revealed the presence ofspherical, sausage- and grape-shaped gromiid morphotypes at bathyal depths (1000-2000m). Analysis of the SSU rDNA and ITS rDNA genes indicated that these gromiids are closelyrelated to shallow-water morphotypes. We identified seven distinctive lineages, five forming amonophyletic group branching as a sister group to shallow water species. Six can be definedmorphologically, while one includes specimens that look identical to specimens from twoother lineages. Each lineage probably represents a separate species, suggesting that deep-sea gromiid diversity is much higher than indicated by their simple morphology. DuringPolarstern Cruise XXII/3 (January-April 2005), we found many gromiids belonging to a similarvariety of morphotypes in trawl and core samples from the continental slope off the Antarcticcontinent. The samples were obtained off Neumayer Station, Kap Norvegica, and the

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Antarctic Peninsula (depths 1100-4450 m). Twenty morphospecies, all undescribed, weretentatively recognised. Particularly notable were: 1) a spherical species which was veryabundant at 1580 m off the Peninsula; 2) a species from 3000-4500 m off Kap Norvegicawith a test wall divided into honeycomb-like cells - a similar wall structure is recognised inone of the Arabian Sea species; 3) a species from 2600 m off the Peninsula in which theorganic test is sometimes partly enclosed within an agglutinated casing. This new evidencefrom the Southern Ocean suggests that deep-water gromiids are widespread and diverse indeep water on continental margins around the world and represent a hitherto overlookedcomponent of deep-sea benthic faunas.

Foraminiferal response to a transient climatic warming event(PETM) as recorded in the GSSP section of the Paleocene/Eoceneboundary at Dababiya, Egypt

Speijer, R.P.(1), Ernst, S.R.(1), Guasti, E.(3) and Dupuis, C.(4)

(1) Department of Geography and Geology, K.U.Leuven, Redingenstraat 16, B-3000,Belgium. [email protected], [email protected](2) Department of Geosciences, Bremen University, P.O.box 330 440, 28334 Bremen,Germany. [email protected](3) Faculté Polytechnique de Mons, rue de Houdain 9, B-7000, Mons, [email protected]

In 2004, the Dababiya section near Luxor, Egypt was chosen to host the GSSP for thePaleocene/Eocene boundary. Although the stratigraphy of this section was studiedintensively prior to this decision, the benthic foraminiferal record hardly was. This was aserious omission, especially since the P/E boundary coincides with one of the biggestextinctions amongst deep-sea benthic foraminifera, associated with the Paleocene/Eocenethermal maximum (PETM). However, benthic foraminiferal records of nearby successions ineastern Egypt have been explored more intensively, showing lower extinction rates on theshelf than in the deep-sea (25% vs. 40% extinction). Here, we present the results of aquantitative survey of benthic and planktic foraminifera across the PETM at Dababiya.Statistical analyses enable a subdivision into three main foraminiferal assemblages: 1) A latePaleocene assemblage suggesting mesotrophic conditions with relatively high productivityand (fluctuating) low oxygen levels. Just below the P/E boundary diversity and densities dropsteeply, coinciding with the onset of the PETM. During the first stages of the PETM a non-calcareous laminated clay bed was deposited under anoxic conditions. The seafloorremained nearly permanently anoxic and a-biotic during this early PETM interval. Onesample contained poorly preserved shallow-dwelling planktic foraminifera (Acarinina), anindication that surface waters remained oxygenated during the early PETM. 2) During themiddle PETM very low densities of a low-diversity/high-dominance benthic fauna indicateoccasional re-oxygenation of the basin, followed by short periods of repopulation of thebenthic environment. 3) During the late PETM, long-term stable communities of foraminiferadeveloped under mesotrophic conditions. Our data underscore the idea that even against abackground of a general greenhouse climate, rapid warming events can have devastatingeffects on various marine ecosystems. Further anomalous events in the early Paleogene arebeing targeted now to explore the uniqueness of the PETM and its effects on microbiota.

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A foraminifera-based paleoenvironmental reconstruction of theDanian/Selandian transition in Egypt

Sprong, J. (1), Guasti, E. (2), Fornaciari, E. (3) and Speijer, R.P. (1)

(1) Laboratory of Stratigraphy, Historical geology, Katholieke Universiteit Leuven,Redingenstraat 16, B-3000, Leuven, Belgium. [email protected]@geo.kuleuven.ac.be(2) Geochronology, Geosciences, University of Bremen, P.O. Box 330 440, 28334, Bremen,Germany. [email protected](3) Department of Geology, Palaeontology and Geophysics, University of Padua, via Giotto1, 35137, Padova, Italy. [email protected]

The Danian/Selandian (D/S) transition may comprise the first of a series of brief intervals ofextremely warm oceans (hyperthermals), of which the Paleocene-Eocene Thermal Maximumis the best-known example. With paleoenvironmental reconstructions changes across theD/S transition will be determined and placed in the context of global signatures of climaticand sea-level change during the middle Paleocene. In Egypt monotonous marls and shalesof the Dakhla Formation are interrupted within the D/S transition by a dark-brown bed, rich inorganic carbon and fish-remains, and with an anomalously high P/B- ratio. Three siteslocated on the stable shelf of Egypt, Gebel Duwi, Qreiya and Aweina (from middle to outerneritic water depth, respectively), were sampled across this anomalous bed. Both plankticand benthic foraminiferal data were used to obtain a picture of paleoenvironmental changesaround the D/S. Planktic foraminiferal assemblages show two main patterns within the D/Stransition. An increase of Acarinina and Parasubbotina suggests lowered salinity andincreased nutrient supply through enhanced river discharge, causing stronger water columnstratification in the central part of the Nile basin (Qreiya and Aweina). Flourishing ofMorozovella and blooming of small Prinsius martinii suggests increased upwelling in theeastern part of the basin (Duwi). Benthic foraminiferal records suggest a sea-level cycle. Thedisappearance of outer neritic taxa, like Angulogavelinella avnimelechi and Anomalinoidesaffinis, indicates a sea-level low at the end of the Danian. At the D/S transition invasion ofopportunistic middle neritic Neoeponides duwi and disappearance of almost all other benthictaxa, is a response to eutrophic conditions and poor seafloor oxygenation during thetransgression. As sea-level rose further N. duwi disappeared and normal assemblagesrestored. Records from other continental margins suggest a eustatic signature of this sea-level cycle. It remains unclear how a large scale sea-level cycle can be matched with aconstant greenhouse climate.

Globorotalia truncatulinoides in the South Atlantic during the mid-late Pleistocene.

Ufkes, E. (1) and Kroon, D. (2)

(1) Vrije Universiteit Amsterdam, de Boelelaan 1085, 1081 HV Amsterdam, the [email protected](2) Vrije Universiteit Amsterdam, de Boelelaan 1085, 1081 HV Amsterdam, the [email protected]

Today, the planktonic foraminifer Globorotalia truncatulinoides is locally present in the SouthAtlantic. Dextrally-coiled specimens are present at low latitudes, whereas sinistrally-coiledones are found sporadically in the (sub)tropics and are more abundantly at higher latitudes,south of 20°S. To reveal the history of the abundance and evolution of G. truncatulinoides,we analyzed core T89-40 (21°36' S, 6°47' E) retrieved from Walvis Ridge, SE Atlantic.To examine to what extent the various morphotypes varying in coiling direction and shape -reflect different habitats during the last million years, their isotopic composition andinterspecific correlations are studied.

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During the last 190 ky, oxygen isotope data of single specimens show a distinct difference inδ18O values between high-conical and flat morphotypes, both sinistral and to a lesser extentalso dextral morphotypes. The heavier values of the flat ones point to another habitat, to apossible subantarctic source area. During the mid-Pleistocene also flat morphotypes arefound occasionally. However, they show no significance difference in δ18O values.Downcore, isotopic values of the various morphotypes show large variations in time whichappear to be related to changes in orbital variations and their effect on the local and regionaloceanography.

Radiogenic isotopes in foraminiferal carbonate as tracers ofcontinental input to the oceans and ocean circulation

Vance, D.

Department of Earth Sciences, University of Bristol, Wills Memorial Building, Bristol BS8 1RJ,UK. [email protected]

Together with the ice-core record of the atmosphere, the foraminiferal carbonate record ofphysicochemical conditions in the oceans has revolutionised our view of the pastenvironment of the Earth. The variability in the oceanic isotopic composition of elements witha radiogenic isotope, and whose residence times in the ocean are shorter than the mixingtimescale (e.g. neodymium(Nd)), reflects local continental inputs and the rate and intensity ofocean circulation (i.e. mixing). Foraminiferal carbonate, given the other information derivedfrom it, is clearly the ideal substrate for recording the past radiogenic isotopic composition ofthe oceans. Here I outline the progress that has been made over the past few years indeveloping this substrate as well, as some of the early applications. Neodymium (Nd)contents of foraminiferal carbonate are low. One of the key obstacles to be overcome in itsuse as a substrate for recording the Nd isotopic composition of the oceans, is the resultantsusceptibility to post-mortem diagenetic additions. The most serious problem is ubiquitousMn-oxide coatings, acquired in the sediment and potentially containing large quantities of Nd.Recent work has shown that these can be cleaned off using well-established techniques andthat the remaining Nd is demonstrably of seawater origin. One remaining puzzle, however, isthe nature of the phase that carries this seawater Nd. Concentrations in cleaned foraminiferaappear to be too high to be contained in the carbonate lattice. Nd isotopes in plankticforaminifera been used for such diverse purposes as quantifying the strength of the Indianmonsoon through time, understanding the role of the river Nile in the genesis ofMediterannean anoxic events, and characterising the glacial inputs to the North Atlantic as afunction of Pleistocene ice-volume changes. Some of these applications will be discussed.

Subtropical North Atlantic Oceanic Variability During MIS3: ThePlanktonic Foraminiferal Record

Vautravers, M.J. and Shackleton, N.J.

Department of Earth Sciences, University of Cambridge, The Godwin Laboratory, NewMuseum Site, CB3 2SA, UK. [email protected]

We have studied ODP Site 1060 on the Blake Outer Ridge, which lies beneath the GulfStream and MD01-2444, off South Portugal. We focus on Marine Isotope Stage 3, 60 to 25thousand years before present (ka). Sea surface temperatures (SSTs) inferred both fromforaminiferal fauna, counts of iceberg melt-out debris, as well as stable isotope analyses,enable our record to be interpreted in terms of regional hydrographic changes. At site 1060the observed SSTs record is consistent with the air temperature record from the Greenlandice cores. However, this record also exhibits differences in detail compared with the ice corerecord, and when compared to other sites within the North Atlantic, significant longitudinaldifferences emerge. At Site 1060 in the western Atlantic all Greenland stadials (GS) whether

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associated with Heinrich Events (HEs) or not, show a similar small amplitude of cooling;mean faunal-based SSTaug during GS is only 1.5ºC colder than during Greenlandinterstadials (GIS). In addition, during GS the coldest SSTs are limited to apparently briefevents. At site MD01-2444 in the eastern Atlantic the present surface hydrography ischaracterised by a strong seasonal variability governed by the intensity/direction changes ofthe offshore winds. In Spring/Summer as the Azores high pressure intensifies, and migratesNorth, the Portugal Current develops, driving upwelling, that cools the core site. In winter theAzores high migrates South, decreasing in intensity, and driving the northward flowing warmPortugal Counter Current. As a result, the upwelling reduces and the area warms. Extremesummer conditions correspond to more positive North Atlantic Oscillation phases, whereasextreme winters correspond to more negative phases. Concentrating on the faunal results,we find that large amplitude coolings identified by the presence of polar species correspondto major events Heinrich events (HE), whereas other cold Dansgaard-Oeschger events arenot as marked. Although in general supporting the correlation with GRIP this group shows apuzzling evolution, (percentages are minimal before each HE). In contrast with the polargroup, the tropical group shows a remarkable correlation with both surface and Greenland18-O records. The percentages of the upwelling-related species show that upwelling wasstrongest during HE6, HE5, HE4 and HE3 but was also very pronounced during the stadialpreceding the Greenland interstadial (GIS) 5 pointing to a reinforced (NAO+), whereas it wasparticularly reduced during GIS16, 9 and 5 (NAO-).

The Miocene/Pliocene boundary in Piedmont (North-Western Italy).Micropalaeontological analyses on outcrop (Moncucco quarry) andsubsurface (Narzole corehole) assemblages.

Violanti, D.(1), Trenkwalder, S. (2), Dela Pierre, F. (3), and Irace, A.(4).

(1) Earth Sciences Department, Turin University, via Valperga Caluso, 35, 10125 Turin; [email protected](2) C.N.R, Geosciences and Georesources Institute, Turin Section, Via Accademia delleScienze 5, 10123 Turin; Italy. [email protected](3) Earth Sciences Department, Turin University, via Valperga Caluso, 35, 10125 Turin; [email protected](4) C.N.R, Geosciences and Georesources Institute, Turin Section, Via Accademia delleScienze 5, 10123 Turin; Italy. [email protected]

The renewed interest for the Messinian salinity crisis had led to new researches in thePiedmont region (North-Western Italy). At the Moncucco quarry (Northern Piedmont), aTortonian-Pliocene succession is well preserved, even if marked by severe tectonicsaccidents. Moreover, the Messinian/Pliocene boundary has been also recovered in theNarzole (Central Piedmont) corehole, stored at the Turin Regional Museum of NaturalSciences.

Both at Moncucco and in the Narzole corehole, the Miocene/Pliocene boundary is marked bya 0.7/1 meter thick black arenitic bed separating the Messinian clayey marls of "Congeria”beds from the Lower Pliocene marls (Argille Azzurre Fm.). Micropalaeontological content ofthe "Congeria” beds consists of Tortonian and Lower Messinian planktonic foraminifers(Globorotalia conomiozea, Gt. suterae) and rare deep shelf to bathyal benthic species(Uvigerina rutila), all interpreted as reworked. Brackish ostracods (Loxochonca djaffarovi) arevery rare. The black arenitic bed, described in many sections of the Northern Apennines, isgenerally barren and very rich in organic matter.

Foraminiferal assemblages of the Pliocene marine succession are rich and diversified. Bothin the outcrop and in the corehole samples, the marls basal part is referable to the ZancleanMPL1 biozone, on the presence of rare to common Sphaeroidinellopsis seminulina.Planktonic specimens are frequent (P/(P+B=60-70%), deep outer neritic to bathyal benthicforaminifers (Anomalinoides helicinus, Hoeglundina elegans, Lingulina seminuda, Uvigerina

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rutila, Vaginulinopsis carinata etc.) are common. Ostracods are rare, with typical open-marine taxa (Bythocypris obtusata).

The microfaunal composition of the basal Pliocene layers is extremely significant, allowingthe correlation with similar assemblages of the Southern Piedmont, undated for the absenceof plankton zonal markers, and documents a deep, open marine palaeoenvironment in thecentral Piedmont Basin at the beginning of Pliocene.

Shark teeth oxygen isotopic evidence for salinity changes andwater column stratification in the Palaeocene-Eocene North SeaBasin

Voigt, S. (1), Zacke, A. (1), Gale, A. S. (2), Joachimski, M. (3)

(1) Institute of Geology and Mineralogy, University of Cologne, Zülpicher Str. 49a, 50674Köln, Germany. [email protected], [email protected](2) Department of Earth and Environmental Sciences, University of Greenwich, ChathamMaritime, Kent, ME4 4TB, UK, and Department of Palaeontology, Natural History Museum,London, SW7 5BD, UK. [email protected](3) Institute of Geology and Mineralogy, University of Erlangen, Schlossgarten 5, 91054Erlangen, Germany. [email protected]

Fossil shark teeth apatite is a useful geochemical archive in shelf sea environments. Themicrocrystalline enamel of shark teeth is precipitated in isotopic equilibrium, is highlyresistant to diagenetic effects, and can be used when calcareous microfossils are absent orpoorly preserved. The orders and families of fossil sharks occupied similar ecological nichesas their modern counterparts, hence providing important and testable palaeoenvironmentalinformation. We studied the oxygen isotopic composition of Palaeocene-Eocene shark teethapatite from marginal and basinal North Sea successions. The teeth represent six families,which differ in their habitat and swimming activity. Most of the teeth belong to the surfacedwelling family Odontaspididae, which are active swimming predators. Representatives ofbottom dwelling groups (e. g. Heterodontidae, Squalidae and Carcharinidae) live morestationary. The oxygen isotope record derived from Palaeocene to Eocene shark teethdisplays a broad range of values ranging from 12 to 23 ‰ SMOW. Oxygen isotope variabilityamong teeth from the same time interval is large, reaches highest values in the earlyYpresian (6-7 ‰) and decrease in the late Lutetian to Priabonian (3-4 ‰). The comparison ofsurface and bottom dwelling species shows the surface dwelling Odontaspidids to bedepleted in 18O by 4-6 ‰ indicating the presence of a pronounced surface-to-bottom watergradient and water column stratification. The most prominent feature is a 5 ‰ negative 18Oexcursion during the Palaeocene-Eocene transition, a time interval that witnessed rapid andsevere global warming and the onset of North Atlantic flood basalt volcanism. Much of the18O excursion indicates changes in seawater isotopic composition and is suggestive for amassive input of isotopic light freshwater. Assuming the modern w-salinity relationship to bevalid in the Eocene North Sea, the 18O decrease would account for a 14-17 ‰ salinitydecrease and the formation of brackish surface waters in the early Ypresian North Sea.

foraminifera and nannoplankton in palaeoceanography · foraminifera and nannoplankton in...

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