provenance characteristics of the brumunddal sandstone in the … · 2016-02-03 · provenance...

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Introduction

The Brumunddal sandstone (informal name) is the uppermost preserved member of the late Paleozoic, rift-related, volcanosedimentary succession in the northern part of the Oslo Rift. It was deposited on a substrate of rhomb porphyry lava, and is preserved in a ca. 6.5 km by 2.5 km, downfaulted block, the Narud halfgraben (Fig. 1). The Brumunddal sandstone consists of red and yel-low, cross-bedded, eolian dune deposits and fluvial chan-nel and floodplain deposits (Rosendal 1929, Larsen et al. 2008). Its maximum depositional age is constrained by a Rb-Sr mineral isochron age of the underlying rhomb porphyry lava at 279±9 Ma (Sundvoll et al. 1990). The absence of overlying, datable rocks leaves the younger limit for the age of deposition unconstrained. Larsen et al. (2008) regarded the sandstone as a remnant of graben fill that formed during the main rifting stage of the Oslo Rift, which is characterized by widespread plateau lavas intercalated by continenal deposits.

Through the U-Pb and Lu-Hf isotope systems and trace element distribution patterns, detrital zircon grains in a sandstone retain a robust memory of the age,

petro genetic history and compositional characteristics of the magmatic or metamorphic rock(s) in which they formed, i.e. of the protosource (e.g. Fedo et al. 2003, Kinney & Maas 2003, Belousova et al. 2002, 2006). As the youngest pre-Quaternary sedimentary deposit in the northern part of the Oslo Rift, this sandstone may have sampled a range of Precambrian and Paleozoic proto-sources in the Fennoscandian Shield, the Caledonian nappes and within the Oslo Rift itself. However, detrital zircons in a sedimentary rock may have been recycled through one or more intermediate reservoirs by erosion and redeposition of older sedimentary rocks (e.g. Røhr et al. 2010).

In this paper, we present the results of an analytical study applying laser ablation inductively coupled mass spec-trometry (LAM-ICPMS) and electron microprobe anal-ysis to detrital zircon in the Brumunddal sandstone. Data include single-zircon U-Pb ages, Lu-Hf isotope ratios and trace element distribution patterns, which provide new insights into the sources and recycling pat-terns of clastic material in Fennoscandia in late Paleozoic time, and which help to refine the position of the sand-stone within the evolutionary history of the Oslo Rift.

Andersen, T., Saeed, A., Gabrielsen, R.H. & Olaussen, S.: Provenance characteristics of the Brumunddal sandstone in the Oslo Rift derived from U-Pb, Lu-Hf and trace element analyses of detrital zircons by laser ablation ICMPS. Norwegian Journal of Geology, vol. 91, pp 1-19. Trondheim 2011. ISSN 029-196X.

The 800 m thick Brumunddal sandstone is partly an eolian, partly a fluvial sandstone deposited in a fault-bounded basin in the northern part of the Oslo Rift in Permian time.The sandstone is the youngest rift-related deposit in the northern part of the Oslo Rift. Well rounded detrital zircons are common accessory mineral grains in the sandstone. U-Pb dating of detrital zircon from a sample of the Brumunddal sandstone by LAM-ICPMS gives a range of ages from (rare) late Archaean ages to Permian (283±4 Ma). The age and initial εHf pattern of zircons in the sediment match the main rock- forming events in Fennoscandia from Archaean to Phanerozoic time. This kind of diverse provenance was most likely obtained by repeated recycling of clastic sediments of Fennoscandian origin, with Silurian, continental sandstones as the most probable direct precursors. Trace element distributions show a conspicuous absence of patterns with the high level of U and Th enrichment typical of zircon from granitic rocks. This is consistent with a complex transport and redepositional history: High U-Th, metamict zircons were selectively removed by abrasion during repeated transport-deposition-erosion cycles. In addition to recycled material, Caledonian syn-orogenic intrusions and Permian intermediate to felsic plutonic rocks in the Oslo Rift itself were minor, but still significant sources of detrital zircon.

Tom Andersen & Roy H. Gabrielsen, Department of Geosciences, University of Oslo, PO Box 1047 Blindern, NO-0316 Oslo, Norway ([email protected]). Ayesha Saeed, GEMOC, Macquarie University, NSW-2109, North Ryde, Australia. Snorre Olaussen, The University Centre in Svalbard, P.O. Box 156, N-9171 Longyearbyen, Norway

Tom Andersen, Ayesha Saeed, Roy H. Gabrielsen & Snorre Olaussen

NORWEGIAN JOURNAL OF GEOLOGY Provenance characteristics of the Brumunddal sandstone in the Oslo Rift

Provenance characteristics of the Brumunddal sandstone in the Oslo Rift derived from U-Pb, Lu-Hf and trace element analyses of detrital zircons by laser ablation ICMPS

2 T. Andersen et al. NORWEGIAN JOURNAL OF GEOLOGY

also analysed U-Pb and Lu-Hf isotopes in detrital zircons from a sample of the Silurian continental sandstone from Orsa in central Sweden.

To evaluate the potential of post-Caledonian continental sediments outside of the rift area as intermediate reposi-tories for detritus in the Brumunddal sandstone, we have

Figure 1a) Simplified geological map of the southern part of the Rendal graben segment in the Oslo Graben, Norway (after Høy and

Bjørlykke 1980). Legend: i: Brumunddal sandstone (Mauset Fm), ii-iv: Permian lavas and volcaniclastic sediments (Bjør-geberg Fm.), v: Bruflat Fm. (Upper Silurian), vi: Ekre shale (Silurian). vii: Pentamerus limestone (lower Silurian), viii: Mjøsa limestone (middle Ordovician), ix: Fluberg Fm (middle Ordovician), x: Cambrian shale and sandstone, xi: Ringsa-ker quartzite (Neoproterozoic). The broken line is an inferred, unexposed fault.

b) Main geological features of the Oslo Rift, after Larsen et al. (2008). Legend: SG Skagerrak Graben, VG: Vestfold Graben, AG: Akershus Graben, RG: Rendal Graben. 1: Mesoproterozoic basement, 2: Hedemark Basin (Neoproterozoic). 3: Cam-brian to Silurian sedimentary rocks, 4: Permo-Carboniferous volcanic and sedimentary rocks. 5: Permian intrusive rocks. 6: Central volcanoes (cauldrons), 7: Transfer zones, 8: Brittle faults. The red rectangle marks the position of Fig. 1a.

c) The outline of the Oslo Rift system, the preserved parts of the Permian deposits (red and deep purple; after Larsen et al. 2008) and its relation to the tectonostratigraphic units mentioned in the text: Legend: C: Caledonian nappes, H: Hedemark Basin (Neoproterozoic), D: Dala-Trysil basin (Mesoproterozoic). TIB: Transscandinavian Igneous Belt (Late Paleoprotero-zoic). O: Orsa sandstone (Silurian), Ö: Öved sandstone (Silurian). On-shore lower Paleozoic sediments in the Oslo Rift are shown in pale blue.

3NORWEGIAN JOURNAL OF GEOLOGY Provenance characteristics of the Brumunddal sandstone in the Oslo Rift

1a). The fill of the Narud halfgraben is subdivided into two formations, namely a lower 250 m thick volcanic unit, the (Bjørgeberget formation) of Early Permian age (Sundvoll et al. 1990), and the upper, conformable c.750 m thick undated Brumunddal sandstone unit, which has been suggested by Eliassen et al. (in prep.) to be renamed the “Mauset formation” (Fig. 2).

The Bjørgeberg formation rests unconformably on folded Cambro-Silurian sediments and consists of four rhomb porphyry lava flows (RPx-u; Rosendal 1928), inter-calated with up to 30m thick, volcanoclastic conglomer-ates and sandstones. The conglomerates consist entirely of rhomb porphyry lava clasts while the sandstones contain 63-65% quartz, 30-32 % feldspar (mostly plagio-clase) and 4-6% lava fragments and hence classify as an arkosic arenite. The volcanoclastic rocks are interpreted as alluvial fans derived from evolving basin-bounding fault escarpments or local highs. Deposition of these fans took place either in interludes between extrusive activity, or represent contemporaneous, lateral variations of the volcanic-sedimentary sequence (Eliassen et al. in prep.).

The Mauset formation (informally the Brumunddal sand-stone) is dominated by red and yellow sandstones with subordinate mudstones and carbonates. The rocks of the Mauset formation can be subdivided into three units. The lowermost unit (c. 200 m thick) consists of red sand-stone with a mineralogical composition and texture sim-ilar to that of the arkosic arenites interlayered with the lavas in the Bjørgeberg formation. They are interpreted as wadi deposits characterized by a stable high water-table. This unit is superseded by a 500 m thick sequence of texturally mature, fine to medium grained subarkosic arenite with up to 77% quartz, 21% feldspar and less than 2% lava fragements. The lowermost 250 m of this unit is interpreted as eolian dune, interdune and sand-flat deposits interbedded by fluvial stream and alluvial plain sandstones and siltstones with evaporite pseudo-morphs. The upper 250 m of the middle unit consists entirely of eolian sands. The Mauset formation is topped by a 50 m thick sequence of texturally and mineralogi-cally im mature sandstones somewhat similar to the lower unit, but which may have more than 40% feldspar and less lava fragments. This arkosic arenite is interbed-ded by siltstones and carbonates that include fresh-water stromatolites. It was deposited in ephermal lakes, ponds and sabkhas typical of a mixed playa and alluvial envi-ronment and is indicative of a second event marked by high water-level (Eliassen et al., in prep.).

Taken collectively, the Mauset formation is a typical eolian/fluvial wadi deposit (Rosendahl, 1929, Olaussen et al 1994, Eliassen et al. in prep.) much like what has been described for the Upper Rotliegendes in the North-ern and Southern Permian Basins in northern Europe (e.g Glennie 1990). The limited outcrops do not allow interpretation of eolian dune types (e.g as barchans, transverse, seif or dras), nor can reliable determinations

Geological backgroundThe late Paleozoic Oslo Rift (Fig. 1) encompasses four separate graben units. The southernmost unit (the Skagerrak Graben) is entirely situated offshore and fea-tures a symmetrical geometry. In contrast, the three on-shore units (Vestfold, Akershus and Rendalen grabens) are half-grabens of contrasting polarities. The graben units are separated by NNW-SSE- and NNE-SSE-strik-ing transfer zones (Fig. 1b). Volcanic rocks and batho-liths dominate the the Vestfold and Akershus grabens, whereas the Rendalen Graben is devoid of batholiths. Still, some lava flows exist here, albeit minor in volume as compared to the southern graben units (Larsen et al. 2008).

The rift evolution can be divided into several distinct stages (Ramberg and Larsen 1978, Neumann et al. 2004, Larsen et al., 2008). The proto-rift stage is characterized by alluvial and minor marine deposits of Pennsylvanian age, the Asker Group (Olaussen et al., 1994, Larsen et al. 2008). Volcanism during the main rifting stage pro-duced basaltic lava (B1) which form thick sequences in the Vestfold Graben, thinning northwards and to zero around Oslo. These lavas are of late Carboniferous to earliest Permian age (300 ± 1Ma, Corfu & Dahlgren 2008). Graben subsidence continued and large volumes of rhomb porphyry lava (latite) and minor basalt erupted through large fissure volcanoes. Also, thick volcanoclas-tic and sedimentary units were deposited during this stage. The composite Larvik pluton in the Vestfold gra-ben intruded in this stage, and has been dated to 298-292 Ma by ID-TIMS U-Pb on zircons (Dahlgren et al., 1996, 1998, Dahlgren 2010). In the subsequent central volcano stage, volcanic activity was concentrated in distinct volcanic centres with local trends of magmatic evolution, terminating in caldera collapse. The central volcanoe s are preserved as between 15 and 20 cauldron struc-tures, representing sections through sub volcanic magma chambers , ring-dike systems and downfaulted blocks of volcanic rocks. U-Pb ages are not yet available for the rocks that formed during this stage, but Rb-Sr ages sug-gest a relatively long duration (ca. 280-240 Ma, Sundvoll et al. 1990). The final stages of rift evolution were charac-terized by emplacement of intermediate to felsic batholiths, ranging in composition from larvikite through syenite to granite. U-Pb ages on zircons from different intrusions suggest emplacement ages between 272 Ma and 286 Ma (Pedersen et al. 1995, Haug 2007, Andersen et al. 2009c), but Rb-Sr isochron ages range down to 241 Ma (Sundvoll et al. 1990).

The Rendalen Graben is delineated eastwards by the westerly facing extensional Rendalen fault and is super-seded to the north by several smaller sub-graben of vary-ing polarity. One of these, informally termed the Narud halfgraben, occupies the Brumunddalen area, its Perm-ian sequence being preserved in the rotated hanging wall fault block of the westerly dipping Gråkvern fault (Fig.


eolian or reworked eolian deposits (Olaussen et al 1994). These beds occur within the volcanoclastics interbedded with the lava pile in the Akershus and Vestfold Graben further south in the Oslo Rift. In a reconstructed paleo-geographic setting, the provenance for the Mauset For-mation is suggested to be both of local origin and from the basin fill of the rift further south.

The Orsa sandstone is an erosional remnant of Silurian continental sandstone preserved within the Siljan impact structure in central Sweden (“O” in Fig. 1c). It is the youngest preserved member of the lower Paleozoic sed-imentary sequence in the area, unconformably overly-ing limestones and shales of Llandowery to Wenlock age (Thorslund 1960). The deposit consists of a cross-bed-ded, conglomeratic to coarse sandy lower part, overlain by a main sequence of loosely consolidated, fine-grained quartz arenite, which is locally carbonate cemented and interlayered with clay-rich units (Hjelmqvist 1966). A

of paleo-wind direction be made. A similar uncer-tainty exists for the sediment transport directions of the ephemeral alluvial stream deposits, which are likely to have been determined by local dune topography and structural grain as developed by graben margin fault-ing (e.g. Gabrielsen et al. 1995). Still, it is considered unlikely that the 750 m thick eolian/wadi deposit of the Mauset Formation was constrained to the 6.5 x 2.5 km half graben in the Brumundal area alone. It is more likely that the Narud halfgraben is one preserved fragment of a wider desert area that covered most of the northern part of the Oslo Rift and its vicinity. Hence the depos-its of the Brumundal sandstone might be interpreted as a northern arm or extension of the Rotliegendes of the Northern Permian Basin (Olaussen et al. 1994, McCann 1998, Larsen et al. 2008, Eliassen et al. in prep). Consis-tent with this interpretation is the occurrence of up to 1 m thick beds of red coloured, cross-stratified sandstone with well-sorted and well-rounded grains interpreted as

Figure 2: Stratigraphy of the Bru-munddal sandstone


grains are well rounded, suggesting significant abration during transport (Fig. 3). A few grains giving Perm-ian U-Pb ages are less well-abraded (Fig. 3e), but lack of rounding is not a universal feature of the youngest group of detrital zircons in the sandstone (compare Fig. 3e with Fig. 3f). Most grains show the low-amplitude, short-wavelength oscillatory zoning in backscattered electron (BSE) intensity that is characteristic of mag-matic zircons (Fig. 3b, c, d). Complex inner structures seen in some grains suggest that they are fragments of twins or intergrown groups of crystals (Fig. 3b). BSE-bright overgrowths occur in some grains (e.g. Fig. 3a,c); these are generally too thin to allow separate analysis by LAM-ICPMS. Mineral inclusions in zircon (e.g. Fig. 3c) were avoided during U-Pb and Lu-Hf analysis, but a few were penetrated during trace element ablations. Inclusions which were large enough to be integrated separately showed elevated phosphorus and middle or light REE, and have therefore been tentatively identified as apatite and monazite, respectively.

sample was included in this study to evaluate the poten-tial of post-Caledonian sediments as intermediate hosts for detrital material, rather than to establish a detailed provenance history. The Orsa sandstone was chosen as an example rather than other Silurian continental sand-stones (e.g. the Öved sandstone in Scania (Jeppson & Laufeld 1986), “Ö” in Fig. 1c; the Ringerrike group in the Oslo Rift) because it is situated between the site of depo-sition of the Brumunddal sandstone and potential Paleo-proterozoic and older protosources in the Svecofennian and Archaean domains of Fennoscandia. The sample studied is a fine-grained, red, friable sandstone without clay or carbonate (Hjelmqvist 1966). Zircon petrographyThe present study was based on a sample of red, friable sandstone from the upper part of the Mauset forma-tion (N 60° 54.59’, E 10° 58.89’). The sample is a car-bonate-cemented quartz sandstone pigmented by finely disseminated iron oxide and containing minor to acces-sory amounts of detrital zircon. Most detrital zircon

Figure 3. Backscattered electron (BSE) images of detrital zircon from the Brumunddal sandstone. Each image is identified by analysis number in tables of the Supplementary Mate-rial, U-Pb age and εHf at the U-Pb age. Each image is identified by ana-lysis number, U-Pb age and eHf at the U-Pb age. Rare Archaean grains (a) are well-rounded and show little inter-nal structure, except for a weak, BSE bright overgrowth (lower part). Paleo- to Mesoproterozoic grains (b, c, d) have well developed, more or less com-plex oscillatory zoning patterns typical for magmatic zircon, and are com-monly well rounded. Permian grains (e, f) vary in shape from angular to well-rounded grain shapes, they show faint oscillatory zoning struc tures, and contain abundant, BSE-dark inclu-sions (feldspar, apatite).


pulse frequency: 5 Hz, beam energy density: ca. 2 J/cm2, static ablation. Each ablation was preceded by a 30 sec-onds on-mass background measurement. Masses 172 to 180 were measured in Faraday collectors, using the stan-dard collector block of the NU Plasma mass spectrom-eter. The total Hf signal obtained was in the range 1.5-3.0 V. Under these conditions, 120-150 seconds of abla-tion are required to obtain an internal precision of ≤ ± 0.000020 (1SE). Isotopic ratios were calculated using the Nu Plasma time-resolved analysis software. The raw data were corrected for mass discrimination using an expo-nential law, the mass discrimination factor for Hf was determined assuming 179Hf/177Hf= 0.7325, the observed 2 SE uncertainty of the Hf mass discrimination factor was better than 0.5%, and was propagated through to the error of the final result. The isobaric interferences on 176Hf by 176Lu and 176Yb were corrected from measure-ments of interference-free 172Yb and 175Lu. The observed mass discrimination for Hf was used as a proxy for those of Lu and Yb. 176Lu/175Lu= 0.02669 was used for correc-tion of Lu interference on mass 176 (DeBievre & Taylor 1993). The 176Yb/172Yb ratio used in the correction pro-cedure (0.5870) was determined from multiple runs of Yb-doped JM475 Hf standard solutions. Lu-Hf analy-ses of zircon from the Orsa sandstone were made with the Nu Plasma HR instrument in Oslo, using procedures described by Andersen et al. (2009a) and Heinonen et al. (2010).

A value for the decay constant of 176Lu of 1.867 x 10-11

a-1 has been used in all calculations (Söderlund et al. 2004; Scherer et al. 2001, 2007). For the calculation of εHf values we used present-day chondritic 176Hf/177Hf = 0.282785 and 176Lu/177Hf = 0.0336 (Bouvier et al. 2008). We have adopted the depleted mantle model of Griffin et al. (2000), modified to the λ176Lu and chondritic com-position used, which produces a present-day value of 176Hf/177Hf (0.28325, εHf = +16.4) similar to that of average MORB over 4.56 Ga, from chondritic initial hafnium at 176Lu/177HfDM = 0.0388.

Trace elements.

Trace elements in zircon were analysed using an Agilent 7500 quadrupole ICPMS and a New Wave Research LUV213 laser microprobe at GEMOC. Ablation conditions were: Beam diameter: 40 μm (aperture imag-ing mode), pulse frequency: 5 Hz, beam energy density: ca. 5 J/cm2, giving a laser energy at the sample of 0.07 mJ. A fast scanning protocol was employed, analysing masses from 29 (Si) to 238 (U), with 10 ms dwell times on all masses analysed except 206 (15 ms), 207 (30 ms) and 238 (15 ms). Ablations lasted for 120 seconds, and each was preceded by a 60 seconds background measurement with the laser off. NIST 610 silicate glass was used as exter-nal standard, with 29Si as the internal standard, assum-ing a stoichiometric composition for zircon with 32.78 weight % SiO2. Data reduction was made off-line using the software package GLITTER 4.4 (Griffin et al. 2008).

Analytical methodsSample preparation was done at the Department of Geo-sciences, University of Oslo, and analysis of zircon by LAM-ICPMS at the GEMOC National Key Centre, Mac-quarie University and at the Department of Geosciences, University of Oslo. Zircon grains were separated from rock samples by standard crushing and mineral separa-tion techniques, followed by hand-picking under a bin-ocular microscope. Selected grains from the two least magnetic fractions (magnetic and non-magnetic at 1.5 A magnet current in the Franz separator at 15º standard tilt and slope) were cast in epoxy disks for LAM-ICPMS analysis. The mounts were ground and polished to expose the zircons, and thoroughly cleaned before analysis. Zir-cons were examined in transmitted and reflected light, and by electron backscatter imaging in a Cameca SX50 electron microprobe. Each imaged zircon was assigned a number, which also serves to identify analyses in Tables 2, 3 and 4 of Supplementary Material. Standards were mounted in separate epoxy disks.

LAM-ICPMS U–Pb dating.

U–Pb dating of the Brumunddal sandstone sample was made with a HP 4500 series 300 inductively cou-pled plasma quadrupole mass spectrometer (QICPMS), attached to a Merchantec/New Wave LUV213 Nd-YAG laser microprobe at GEMOC. Analytical procedures were as described by Jackson et al. (2004). The analyti-cal protocol allows accurate correction for U/Pb frac-tionation by sample-standard bracketing. Standard zir-con GJ-1 (608 Ma, Jackson et al. 2004) was used for cal-ibration, while standard zircons 91500 (Wiedenbeck et al. 1995) and Mud Tank (Black and Gulson 1978) were run frequently as unknowns to provide an independ-ent control on reproduci bility and instrument stability. The GLITTER software (Griffin et al. 2008) was used for data reduction and calculation of individual U–Th–Pb ages. The contents of common lead were estimated from the 3D discordance pattern in 206Pb/238U – 207Pb/ 235U – 208Pb/232Th space, and corrected accordingly (Andersen 2002).

Additional U-Pb analyses of detrital zircon from the the Orsa sandstone were made with a Nu Plasma HR multi-collector ICPMS and a NewWave LUV213 laser micro-probe at the Department of Geosciences, University of Oslo, using protocols for data acquisition and standard-ization described by Rosa et al. (2009).

Lutetium-hafnium isotopes.

Lu-Hf analyses of zircon from the Brumunddal sand-stone were made with a NuPlasma multicollector ICPMS attached to a LUV213 Nd-YAG laser microprobe at GEMOC, using protocols described by Griffin et al. (2000) and Andersen et al. (2002b). Ablation conditions were: Beam diameter: 55 μm (aperture imaging mode),


(2.6 Ga) to Permian (Fig. 4a), with a pronounced fre-quency maximum at ca. 1 Ga, and subordinate maxima at ca. 1400 Ma, 1600 Ma, 1800 Ma and in the Phanero-zoic, with marked hiatuses in the Neoproterozoic and early Paleoproterozoic (Fig. 5a). Although the magnetic and non-magnetic zircon fractions show largely similar age distribution patterns, a distinct group of late Paleo-zoic zircons (270-310 Ma) has been observed only in the magnetic fraction (Fig. 4a). Of eleven zircons in this group, eight are 10 % or more discordant. The three con-cordant zircons give a concordia age of 285±4 Ma, and 9 zircons define a weighted average 206Pb/238U age of 283±4 Ma (Fig. 4b, 5b), indistinguishable from the concordia age. Another group of similar size (9 grains) give ages

Accuracy and external precision of the individual ele-ments estimated from repeated analyses of reference zir-con GJ-1 are given in Table 1 of Electronic Supplement.

Results

Uranium-lead ages of detrital zircons in the Brumunddal sandstone.

Of a total of 105 grains dated by U-Pb (Table 2 of Elec-tronic Supplement), 94 were concordant or less than 10 % normally discordant (central discordance). The zir-cons yield a large range of U-Pb ages, from late Archaean

0.04

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238U/206Pb

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/206 Pb

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240

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0.037

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8 U

Weighted average 206Pb/ 238U age:283±4 (95% conf.), 9 of 10 grains

Wtd by data-pt errs only, 1 of 10 rej.MSWD = 1.7

Concordia Age = 285 ±4 Ma(2 ,� decay-const. errs ignored)

MSWD of concordance and equivalence = 1.6

a

b

Figure 4. U-Pb data for detrital zircon from the Brumunddal sandstone.a: Tera Wasserburg diagrams showing

data for zircon crystals in the magne-tic and non-magnetic fractions from the Franz magnetic separator at 1.5 A separately. Note that Permian zircons occur only in the magnetic fraction.

b: Conventional concordia diagram showing the Permian fraction. The three grains represented by white fill define a concordia age at 285±4 Ma, the fraction as such a weighted average 206Pb/238U age at 283±4 Ma, which is the preferred estimate of the crystallization age of the source rock(s).


Lutetium-Hafnium isotopes of detrital zircon in the Brumund dal sandstone

In Fig. 6 (data from Table 3 of Electronic Supplement), initial 176Hf/177Hf for 82 concordant or near-concor-dant zircons are plotted at the preferred U-Pb age (i.e. 207Pb/206Pb ages for zircons older than 600 Ma, 206Pb/238U ages for younger zircons).

The late Paleozoic zircons form a coherent group with distinct initial Hf character. When zircons that are more than 10% discordant in U-Pb are included in the calcu-lation, nine zircons give a weighted average 176Hf/177Hf=

between 526 and 398 Ma, with a peak at 440 Ma, which is compatible with igneous or metamorphic source rocks in Caledonian nappes (e.g. Gee et al. 2008). Two analyses give ages of 346±4 Ma and 361±4 Ma. These grains do not differ from the Caledonian fraction in terms of trace element distributions and Lu-Hf characteristics (below), and it is therefore suggested that they are Caledonian grains which have suffered sufficient lead-loss in Perm-ian or recent time to modify their ages, while remaining concordant within error.

Orsa sandstone, Sweden (Silurian)Brumunddal sandstone

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Figure 5. Accumulated probability dis-tribution diagrams showing:

a): The whole population of dated zir-cons (207Pb/206Pb ages for t> 600 Ma, 206Pb/238U ages for t< 600 Ma), analyses with more than ± 10 % discordance excluded. The colour-filled background histogram shows the age distribution of detrital zir-cons in the Silurian Orsa sandstone, Sweden (Table 5a of Supplementary material).

b): Permian zircons (n=11, including discordant grains). Broken outline indicates zircons that are not used to calculate ages.


variation from εHf= -11 to +1.4, indicating that this age fraction must have come from sources with different crustal histories. An even larger internal variation is seen in the large group of Sveconorwegian zircons, which span 20 epsilon units (-11 to +9). Zircons in the 1400-1500 Ma age group have positive εHf, except for a small, coherent group with εHf= -3 to -8. These may be early Mesoproterozoic or older zircons that have been affected by lead loss around 1500 Ma. Some of the Paleoprotero-zoic zircons (1600-2000 Ma) have low-positive initial εHf, but zircons with negative εHf are also present in this age group. Unfortunately, only one single late Archaean grain

0.28272±0.00004 (95% confidence) or εHf=4.2±1.5, with no rejections. The spread of initial 176Hf/177Hf in this group is comparable to the analytical error, suggest-ing that these zircons originated from one or more pro-tosource rocks within the rift with homogeneous Lu-Hf characteristics.

Zircons older than these show considerable variation in initial 176Hf/177Hf, ranging from well below CHUR (i.e. εHf<0) to values near the depleted mantle growth curve at the crystallization age (Fig. 6), without simple correlation with age. The “Caledonian” age group shows internal

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Sveconorwegian granites

Granite and rhyoliteTelemark block

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Inherited zircon in TIB,Intrusions in theArchaean Domain

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Oslo Riftmagmas

Age range of Caledonianmagmatism

TransscandinavianIgneous Belt (TIB)Magmatic zircon

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Late Arcaheangranitoids, Finland

Silurian sandstone from Orsa, Sweden

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Detrital zircon age, Ma

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alH

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f17

617

7

Figure 6. Initial 176Hf/177Hf plotted agains U-Pb or Pb-Pb age for detrital zircons in the Brumunddal sandstone (white fill: Non-magnetic fraction, grey fill: Magnetic fraction), compared to fields of initial Hf isotope composition for magmatic rocks in Fennoscandia: Late Archaean granitoids: Patchett et al. (1981), Lauri et al. (2011). Intrusions in the Archaean domain, Finland: Patchett et al. (1981). Transscandinavian Igneous Belt, and inherited zircons therein: Andersen et al. (2009a). Mesoproterozoic “Gothian” arc magmatism, Telemark magmatism and Sveconorwegian granitoids: Andersen et al. (2002, 2004, 2007, 2009b), Pedersen et al. (2009). Oslo Rift magmas: Haug (2007), Andersen et al. (2009c). The fields with diagonal ruling are the observed fields of detrital zircons in a sample of Neoproterozoic sandstone from the Hedmark Basin published by Bingen et al. (2005a). The ages of syn-orogenic Caledonian magmatism are constrained by U-Pb data on subduction-related igneous rocks in the Caledonian nappes (Gee et al. 2008 and references therein). The Hf isotopic composition of these rocks remains unconstrained by data. The broad, open arrow represents the evolution of TIB and related Paleoproterozoic granitioids with time, based on observed 176Hf/177Hf in zircon, and an assumed average 176Lu/177Hf = 0.010. Broken arrows are trends of apparent evolution of 176Hf/177Hf in zircons which have lost all or part of their radio-genic lead during secondary, ancient events. Thin, broken lines are contours of 176Hf/177Hf at 2 epsilon units interval from -10 to +10. The colour-filled background points are zircons from the Silurian Orsa sandstone, Sweden (data from Table 5b of Supplementary Material).


group with relatively low HREE enrichment (Yb/Sm)CN = 20-30). Of the 11 grains in this group, four have dis-tinctly shallower Eu anomalies than the rest (Eu/Eu*>0.4, compared to Eu/Eu*≤ 0.3, Fig. 9). The patterns of the latter resemble those of Oslo Rift larvikite analysed by Belousova et al. (2002) in terms of pattern curvature and Eu anomaly, but at an overall lower REE enrich-ment level. The differences in concentration level may, however, be an effect of the different methods of inter-nal standardization used in the two studies (assumed stoichiometric SiO2 value in this study vs. Hf analysed by electron microprobe).

U-Pb and Lu-Hf characteristics of Silurian sandstone

The age pattern of detrital zircon in the Silurian Orsa sandstone mimics that of the Brumunddal sandstone with age maxima in the late Paleoproterozoic, at ca. 1500 Ma and in the late Mesoproterozoic (Fig. 5a, data from Table 5a of Electronic Supplement). There is also a small contribution of Phanerozoic zircon, presumably from a Caledonian source. The variation of initial Hf isotope character also overlaps that of the Brumunddal sand-stone (Fig. 6, data from Table 5b of Electronic Supple-ment l). The clearest difference between the two distri-bution patterns is due to a single, highly U-Pb discordant zircon with εHf=-21 at 1376 Ma (Orsa-38, Table 4); this is most probably a late Archaean or Paleoproterozoic zir-con that has lost a significant amount of lead in a thermal event in Mesoproterozoic time.

Discussion

U-Pb, Lu-Hf and potential protosources of detrital zircon in the Brumundal sandstone.

The detrital zircon ages from the Brumunddal sandstone range from late Archaean to Phanerozoic, with initial Hf istope signatures from near depleted mantle to crustal ratios. The distribution of age and initial 176Hf/177Hf or εHf in Fig. 6 is, however, far from random, and can be related to known crustal evolution events in Fenno scandia.

Precambrian protosources. The near-CHUR initial 176Hf/177Hf of the single late Archaean detrital zircon ana-lysed for Lu-Hf falls within the age and 176Hf/177Hf range of late Archaean granitoids from eastern Fennoscandia (Patchett et al. 1981, Lauri et al. 2011). Archaean rocks are exposed only in E Finland, NE Sweden N Norway and NW Russia, at considerable distance from their sites of deposition.

The Precambrian rocks of the Fennoscandian shield immediately bordering the Oslo Rift (Fig. 1c) belong to the late Paleoproterozoic Transscandinavian Igneous Belt (TIB, Högdahl et al. 2004) and the early Mesopro-terozoic (“Gothian”) magmatic arc fragments (Andersen et al. 2004). The TIB was formed by multiple episodes

could be analysed for Hf isotopes, and yielded near-chondritic 176Hf/177Hf at its 207Pb/206Pb age.

Trace element compositions of detrital zircon in the Bru-munddal sandstone

The trace element distribution patterns observed in the analysed samples are typical for magmatic zircon (Hoskin and Schaltegger 2003, Belousova et al. 2002), with positive anomalies for Hf, U, Th and Ce (Fig. 7, data from Table 4 of Electronic Supplement). Hf concentra-tions range from ca. 0.6 to ca. 2.4 percent, and total REE from 33 to 2000 ppm. Source-dependent trace element combinations spread from the less U and LREE enriched part of the field of variation of zircon from granitoids towards that of zircon from mafic rocks (Fig. 8, fields from Belousova et al. 2002). This is reflected by the CART classification algorithm of Belousova et al. (2002), which gives a dominance of “dolerite” and different types of “granitoids” as suggested source rocks (Table 1). A few zircon analyses indicate source rock types such as “kim-berlite” and “carbonatite”. Although both rock types are known to exist in Fennoscandia (e.g. O’Brien et al. 2005, Rukhlov & Bell 2010), they are rare, and unlikely to have yielded significant amounts of detrital material to the Brumunddal sandstone. Zircon grains indicating uncommon source rock types show anomalous REE pat-terns with low HREE and /or HREE / LREE ratios, com-bined with Eu/Eu* > 0.5 (NM15A-02, 04, 17, 21, 29, 32, 45, 66, Fig. 9) and probably formed by crystalli zation from hydrothermal solutions or during metamorphism rather than from magma; the relatively flat HREE pat-tern in NM15A-32 suggests coexistence with garnet (e.g. Hoskin & Schaltegger 2003).

Chondrite normalized REE distribution patterns are strongly enriched in the heavy REE, as is common in zir-con; all grains analysed have a marked positive Ce anom-aly and a variable, negative Eu anomaly (Fig. 9). A major-ity of the analyses have (Yb/Sm)CN= 30 to 200, and deep, negative Eu anomalies (Eu/Eu* < 0.4). With the excep-tion of a few grains with apparent LREE enrichment due to the presence of solid inclusions (see below), none of the zircons analysed from the Brumunddal sandstone show the characteristic flattening of the LREE pattern observed in zircons from “granitoids” by Belousova et al. (2002), and the patterns in general resemble those of zir-con from “dolerite” and “basaltic” sources (Fig. 9).

Anomalous LREE-enrichment seen in a few analy-ses (e.g. NM15A-57 and -67) are from ablations that have picked up minor amounts of LREE-rich inclusions (monazite?) in the zircon. Other anomalous analyses show relative enrichment of middle REE and a shallow Eu anomaly (e.g. NM15A-37, Fig. 9). Again, this is due to accidental ablation of small inclusions in the zircon, in this case most probably of apatite.

The zircons of late Paleozoic age form a consistent


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Figure 7. Spider dia-grams showing the over-all variation of zircon compositions in the Brumunddal sandstone, normalized to chondritic values of McDonough and Sun (1995). The shaded background field is the interquartile range of zircon compositions in granitoids (Belousova et al. 2002).

Figure 8. Source-indicat ing element and element -ratio plots showing that a significant proportion of the detrital zircons ana-lysed falls between the main fields of zircon derived from granitoid and mafic (i.e. basalt, dolerite) sources (reference fields from Belousova et al. 2002).


Larvikite,interquartile range,Belousova et al. (2002)

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Figure 9. Chondrite normalized REE patterns for zircon from the Brumunddal sandstone, divided into six groups (<320 Ma; 320-900 Ma; 900-1250 Ma divided in groups with deep and shallow Eu anomalies, respectively; 1400-1500 Ma; >1600 Ma, see text for further explanation). Reference fields for all except the <320 Ma groups are interquartile ranges of variation of zircon from granitoids, dolerites and basalts; for the <310 Ma group, the interquartile range of zircon from the Oslo Graben larvikite is shown instead (all reference data from Belousova et al. 2002). Analyses have been normalized to the chondrite values of Boynton (1984).


Caledonian protosources. Synorogenic intrusions in the nappes of the Scandinavian Caledonides that could be sources of early Paleozoic detrital zircon have been dated to 430-500 Ma (Gee et al. 2008 and references therein). The Caledonian mountain chain was mainly levelled by mid-Carboniferous time (Gabrielsen et al. 2005, 2010), but late Permian – Triassic uplift is likely to have enhanced relief to the west and northwest of the Oslo Graben system (Rohrman et al. 1995, Gabrielsen et al. 2010). By the early Triassic, sediments of Caledonian ori-gin were transported southwards to become deposited in the Central European Basin (Paul et al. 2009). Unfor-tunately, no Hf isotope data are available from Caledo-nian intrusions. The considerable range of εHf (+ 1.4 to -11) observed suggests, however, that these zircons either crystallized from magmas with variable amounts of a TIB-like crustal component, or that they are zircons from Sveconorwegian protoliths that have lost lead in Caledonian metamorphism.

Within-rift sources. Permian grains make up ca. 10 % of the analysed detrital zircon population (Fig. 5). Rocks from the Larvik pluton have been dated to 292-298 Ma by U-Pb on zircon and baddeleyite (Dahlgren et al. 1998, Dahlgren 2010). This event was, however, followed by the emplacement of syenitic to granitic plutons around 280 Ma (Pedersen et al. 1995, Haug 2007). Magmatic zircon from larvikite, nordmarkite and biotite gran-ite in the ca. 280 Ma Sande and Drammen plutons have εHf in the range - 4 to +6, whereas zircons from pegma-tites in the Larvik pluton are slightly more radiogenic at εHf = +8 ± 2 (Andersen et al. 2009b); no evidence has so far been found of hafnium derived from a late Paleo-zoic depleted mantle reservoir (εHf ≈ + 15) in any of these rocks. The 176Hf/177Hf at 280 Ma of the late Paleozoic zircons falls within the age and Hf isotope range of zir-con in the younger group of intermediate to felsic intru-sions in the rift. Two distinct types of REE patterns have been observed, with “deep” and “shallow” Eu anoma-lies, respectively (Fig. 9). The first group has REE pattern geometry similar to that of zircon from larvikite reported by Belousova et al. (2002), and therefore most likely orig-inates from intermediate intrusive rocks. The other type must originate from other syenitic or (alkali) granitic plutonic rocks, which cannot be identified.

Recycling of sedimentary rocks

Most of the main documented crust-forming events in Fennoscandia are represented in the detrital zircon pop-ulation of the Brumunddal sandstone, including acces-sory late Archaean and Paleoproterozoic zircons that must have originated in protosources east of the Trans-scandinavian Igneous Belt. It is highly unlikely that zir-con from such a wide range of sources could have been brought into the rift in a single event of one-way trans-port from protosource to depositional basin. Rather, zir-con must have been recycled through deposition in inter-mediate, sedimentary reservoirs followed by erosion and

of magmatic intrusion in the period 1.88 to 1.68 Ga; the TIB intrusions close to the Oslo Rift belong to the young-est part of the belt, known as TIB3, with intrusive ages around 1.68-1.67 Ga (Larson and Berglund 1992, Heim et al. 1996, Andersen et al. 2009a). Despite the large size and long time of emplacement of the TIB province, the initial Hf signature of magmatic zircon from TIB gran-itoids shows little variation, which can be represented by initial εHf= +2±3 at 1.88 Ga and 176Lu/177Hf≈ 0.015 (Andersen et al. 2009a). Given the short distance to potential source rocks within the TIB, the low abundance of TIB-like detrital zircons in the Brumunddal sandstone (Fig. 5a, 6) is somewhat surprising. On the other hand, a small group of Paleoproterozoic zircons with nega-tive εHf overlaps the field of inherited zircon of possible Archaean origin in a TIB intrusion at the eastern margin of the belt in Sweden (Andersson et al. 2006, Andersen et al. 2009a). Furthermore, Paleoproterozoic zircons with such initial Hf characteristics are found in Paleoprotero-zoic granites within the Archaean domain of Finland (Patchett et al. 1981, Andersen & Lauri 2010). Paleopro-terozoic crust with Lu-Hf properties similar to the rocks of the Transscandinavian Igneous Belt or their source in the deep crust has contributed source material to most of the Mesoproterozoic crustal magmatic events that can be recognized in southwestern Fennoscandia, even far west of the present TIB outcrop area (Andersen et al. 2001, 2002a, 2009b, Andersen 2005, Pedersen et al. 2009).

Detrital zircons of early Mesoproterozoic age with initial 176Hf/177Hf approaching the DM curve resemble zircons from both Mesoproterozoic continental margin arc com-plexes (Andersen et al. 2002b, 2004) and those from fel-sic rocks from the Telemark block, which are still poorly constrained by Lu-Hf data. A small, coherent group of 1.45-1.50 Ga zircons with εHf= -3 to -8 can either be derived from a coeval, crustal source, or they can be TIB-derived zircons that have lost lead in a Mesoproterozoic tectonothermal event.

During the Sveconorwegian period, southwestern Fen-noscandia was affected by several episodes of mafic and felsic magmatism in different tectonic settings, rang-ing from ca. 1300 Ma to 920 Ma (Bingen and van Bree-men 1998, Andersen et al. 2001, 2002a,b, 2007, 2009b, Vander Auwera et al. 2003, Pedersen et al. 2009). Mag-matic events involving crustal underplating with mafic material with a depleted mantle Hf isotope signature (εHf ≈ +12) at 1.3 and 1.22 Ga have been documented in the Telemark block; after each of these events, the initial Hf isotope composition of zircon from magmatic rocks evolved towards less radiogenic compositions due to increasing effects of crustal source components (Ander-sen et al. 2007, Pedersen et al. 2009). Initial εHf of the large group of Sveconorwegian zircons overlaps well with the combined range of magmatic and inherited zir-con from Sveconorwegian granitoids (Andersen et al. 2002a, 2007, Pedersen et al. 2009).


sediments with a long and complex transport history.

The significance of Neoproterozoic detrital zircon ages in southwestern Fennoscandia.

The Neoproterozoic was a quiet period in Fennoscan-dia, with little or no production of zircon-fertile igneous rocks. Nevertheless, Neoproterozoic detrital zircon ages have been reported from both the Neoproterozoic Hed-mark basin (Bingen et al. 2005a) and from the Carbon-iferous Asker Group within the Oslo Rift (Dahlgren & Corfu 2001). In the Brumunddal sandstone, such zircons are conspicuously absent. A non-Fennoscandian source for Neoproterozoic zircon has been suggested (Dahlgren & Corfu 2001), but the range of 176Hf/177Hf in Neopro-terozoic zircons in the Hedmark Basin with the observed U/Pb ages is fully compatible with Neoproterozoic loss of radiogenic lead in zircon from Sveconorwegian granito-ids (Fig. 6). This could be caused by surface weather-ing prior to deposition, or by interaction with diagenetic fluids within the Hedmark Basin.

Time of deposition and tectonostratigraphic status of the Brumunddal sandstone

The weighted average U/Pb age of 283±4 Ma (Fig. 3b) confirms the previous estimate of the maximum age limit for sedimentation based on Rb-Sr ages of the underlying rhomb porphyry lavas (Sundvoll et al. 1990, Larsen et al. 2008). By the time of deposition of the Brumunddal sandstone, rocks belonging to the ca. 280 Ma “batholith stage” of rift evolution must have been exposed to ero-sion at the surface, which suggests that deposition took place during the final stages of rift evolution (stage 6 in the chronology of Larsen et al. 2008), rather than during or immediately after rhomb porphyry volcanism (i.e. in stage 3), which preceded emplacement of the younger, batholitic bodies. Plausible sources of Permian zircon are only exposed to the south of the site of deposition, in the intrusive complexes of the Akershus and Vestfold graben segments. These zircon grains must therefore have been transported from south to north along the rift axis. The observation that some of these zircons are quite severely rounded due to abrasion during transport indicates sig-nificant transport for some, but not for all of the young zircons observed.

The present data suggest that sediment transport took place from south to north along the graben axis, perhaps suggesting a topographic gradient in this direction. It is of particular interest to note that one of the REE-patterns shows the presence of a deep (plutonic) source, sug-gesting that plutons became exposed and eroded in the southern part of the graben simultaneously with ongoing volcanism in the Brumunddal area. This situation is not unique and is paralleled in the present East African rift system (Barberi et al. 1970, 1972).

new transport. This has eventually caused a relatively well mixed sample of the entire Fennoscandian surface to be brought into the Oslo Rift, including far-transported material from eastern Fennoscandia.

The close similarity in age and initial 176Hf/177Hf distribu-tion of detrital zircon in the Brumunddal and Orsa sand-stones indicates that Silurian sandstone is a very likely immediate precursor. Silurian, continental deposits may have had a wide distribution in western and central Fen-noscandia in post-Caledonian time; outside of the Oslo Rift they are now preserved only as small erosional rem-nants. Like the Orsa sandstone, the late Silurian Ringer-rike Group within the Oslo Rift itself (Davies et al. 2005 and references therein) contains material derived from both Fennoscandian and Caledonian sources (Turner & Whitaker 1976, Dahlgren & Corfu 2001).

The Silurian continental sediments make up the young-est of several cover sequences in Fennoscandia, ranging in age from Paleoproterozoic (e.g. Claesson et al. 1993, Lundqvist & Persson 1999, Lahtinen et al. 2002, Bergman et al. 2008), through Mesoproterozoic (e.g. Bingen et al. 2001, 2003, 2005b, Kuhonen & Rämö 2005, Andersen et al. 2004, Lamminen & Köykkä 2010) and Neoprotero-zoic (e.g. Nystuen et al. 2008, Bingen et al. 2005a, Lam-minen et al. 2008, 2009) to Phanerozoic (e.g. Thorslund 1960, Bjørlykke 1974a, Turner & Whitaker 1978, Davies et al. 2005). Each of the successive cover sequences must have contained clastic material recycled from older deposits, as well as detritus derived directely from crys-talline protosource rocks.

Basins such as the late Vendian – Cambrian Peri-Thorn-quist, and the Pre-Baltic sub-basins (Sliaupa et al. 1997, Poprawa et al. 1999), the southwestern part of the Bal-tic Basin (Lazauskiene et al. 2002), as well as the Scandi-navian (Bjørlykke 1974b, Worsley et al. 1983) and Ger-man-Polish Caledonian foreland basins (Lazuskiene et al. 2002) may have acted as intermediate repositories for far-transported detritus, including Paleoproterozoic and Archaean detrital zircons of east Fennoscandian origin. The Caledonian forebulge may have promoted uplift and erosion of these basins, thus releasing zircons of an east-erly origin.

The most zircon-fertile rocks within each of the proto-source-terranes are granitic. Nevertheless, the trace ele-ment patterns are more in line with mafic to intermediate source rocks than with granite. Zircons with a relatively less steep LREE pattern are also likely to be more heav-ily enriched in uranium and thorium (Fig. 7; Belousova et al. 2002), and would therefore more easily become metamict due to internal radiation damage than less U and Th enriched (and hence also more strongly LREE depleted) ones. Metamict zircon is brittle and much more likely to be destroyed by abrasion during transport than grains with an intact crystal structure. A scarcity of typical “granitoid” zircon is therefore to be expected in


References

Andersen, T. 2002: Correction of common lead in U-Pb analyses that do not report 204Pb. Chemical Geology 192, 59-79.

Andersen, T. 2005: Terrane analysis, regional nomenclature and crus-tal evolution in southwestern Fennoscandia. GFF 127, 157-166.

Andersen, T. & Lauri, L.S. 2010: Variable Archaean sources for Paleo-proterozoic Nattanen-type granites in northern Finland: Implica-tions of Lu-Hf isotope data on magmatic zircon from the Riesto-vaara and Nattanen intrusions. Abstract, 29th Nordic Geological Winter Meeting, Oslo, 11-13 January 2010. NGF Abstracts and Proceedings 2010, 1, 6.

Andersen, T., Andresen, A. & Sylvester, A.G., 2001: Nature and dis-tribution of deep crustal reservoirs in the southwestern part of the Baltic Shield: Evidence from Nd, Sr and Pb isotope data on late Sveconorwegian granites. Journal of the Geological Society, London 158, 253-267.

Andersen, T., Griffin, W.L., Jackson, S.E., Knudsen, T.-L. & Pearson, N.J. 2004: Mid-Proterozoic magmatic arc evolution at the south-west margin of the Baltic Shield. Lithos 73, 289-318.

Andersen, T., Griffin, W.L. & Sylvester, A.G. 2007: Sveconorwegian underplating in southwestern Fennoscandia: LAM-ICPMS Hf iso-tope evidence from granites and gneisses in Telemark, southern Norway. Lithos 93, 273-287.

Andersen, T., Andresen, A. & Sylvester, A.G., 2002a: Timing of late- to postorogenic Sveconorwegian granitic magmatism in the Telemark and Rogaland-Vest Agder sectors, S. Norway. Norges geologiske undersøkelse Bulletin 440, 5-18.

Andersen, T., Griffin, W.L. & Pearson, N.J., 2002b: Crustal evolution in the SW part of the Baltic Shield: The Hf isotope evidence. Journal of Petrology 43, 1725-1747.

Andersen, T., Andersson, U.B., Graham, S., Åberg, G. & Simonsen, S.L 2009a: Granitic magmatism by melting of juvenile continental crust: New constraints on the source of Paleoproterozoic granitoids in Fennoscandia from Hf isotopes in zircon. Journal of the Geologi-cal Society, London 209, 233-247.

Andersen, T., Graham, S. & Sylvester, A.G. 2009b: The geochemis-try, lutetium-hafnium isotope systematics and petrogenesis of late Mesoproterozoic A-type granites in southwestern Fennoscandia. Canadian Mineralogist. 47, 1399-1422.

Andersen, T., Simonsen, S.L. & Haug, L.E. 2009c: LAM-ICPMS Lu-Hf isotope data on magmatic zircons from felsic and interme-diate intrusions in the Oslo Rift: Constraints on the mantle source. Abstracts, NGF Winter Conference, Bergen, Jan. 2009. Norsk Geo-logisk Forening Abstracts and Proceedings 2009, 1, 3-4.

Andersson, U.B., Högdahl, K., Sjöström, H. & Bergman, S. 2006: Mul-tistage growth and reworking of the Palaeoproterozoic crust in the Bergslagen area, southern Sweden: evidence from U-Pb geochro-nology. Geological Magazine 143, 679-697.

Barberi, F., Borsi, S., Farrera, G., Marinelli, G & Varet, J., 1970: Rela-tions between tectonics and magmatology in the northern Dana-kil depression (Ethiopia). Royal Society of London Philosophical. Transactions, Ser.A., 267, 293-311.

Barberi, F., Borsi, S., Farrera, G., Marinelli, G., Santacroce, R., Tazieff, H. & Varet, J. 1972: Evolution of the Danakil depression (Afar, Ethiopia) in light of radiometric age determinations. Journal of Geology 80, 720-729.

Belousova, E., Griffin, W.L., O’Reilly, S.Y. & Fisher, N.I., 2002: Igneous zircon: trace element composition as an indicator of source rock type. Contributions to Mineralogy and Petrology 143, 602–622.

Belousova, E.A., Griffin, W.L. & O’Reilly, S.Y. 2006: Zircon crystal morphology, trace element signatures and Hf isotope composition as a tool for petrogenetic modelling: Examples from eastern Aust-ralian granitoids. Journal of Petrology 47, 329-353.

Bergmann, S., Högdahl, K., Nironen, M., Ogenhall, E., Sjöström, H., Lundqvist, L. & Lahtinen, R. 2008: Timing of Palaeoproterozoic intra-orogenic sedimentation in the central Fennoscandian Shield;

Why are Permian zircons only found in the magnetic fraction? Permian zircons were only found in the magnetic fraction at 1.5 A. With ca. 10% of the total number of analyzed zircons, this fraction is relatively large. However , if each of the two fractions from the magnetic separator are considered individually, their sizes are not sufficient to guarantee detection of even relatively large age fractions in each (Andersen 2005). However, it is still fully possible that the absence of syn-rift zircons from the non- magnetic fraction reflects a real physical property of these zircons. If so, relatively standard use of magnetic separation has efficiently removed them from the least magnetic fraction. The tendency of magnetic mineral separation to introduce undesirable bias in detrital zir-con populations was pointed out by Sircombe and Stern (2002), and the present results could imply that such effects can be due to even a moderate use of the magnetic separator.

ConclusionsThe Brumunddal sandstone was deposited during the final stages of evolution of the Oslo Rift, at a time when plutonic rocks formed during the ca. 280 “batho-lith” stage were exposed to erosion. The sandstone con-tains detrital zircon ranging in age from late Archaean to Permian. Combined U-Pb and Lu-Hf data suggest that detrital zircons from most of the region-wide petroge-netic events in Fennoscandia are represented in this sin-gle sediment, including zircons formed in events not rep-resented by rocks within reasonable distance from the site of deposition. The likely explanation for this broad distribution of detrital zircon is recycling of material from Phanerozoic sedimentary cover on Fennoscandian basement, which may in turn contain material recycled from still older sedimentary rocks. Repeated transport and deposition has effectively mixed detrital zircon from a wide range of protosources, and depleted the detritus in metamict, high U zircons with typical “granitoid” trace element distribution patterns, leaving a population with a large proportion of zircons having trace element distri-butions more characteristic of “mafic” source rocks.

Acknowledgments. - The research reproted her could be carried out thanks to economic support from the University of Oslo and Macqua-rie University. Thanks are due to Trine-Lise Knudsen for assistance in the field, Gunborg Bye-Fjeld for technical assistance with mineral sepa-ration, Justin Payne for help with the LAM-ICPMS, to Elena Belousova and Norman Pearson for many helpful discussions, and to Bernard Bingen and an anonymous reviewer for helpful comments. T.A. wants to thank GEMOC and its directors S.Y. O’Reilly and W.L. Griffin for repeated invitations to spend fruitful research time in Australia . This is publication no. 17 from the Isotope Geology Laboratory at the Department of Geosciences, University of Oslo and contribution 696 from the Australian Research Council National Key Centre for the Geochemical Evolution and Metallogeny of Continents (http://www.gemoc.mq.edu.au).


Journal of Geology 85, 193-201.DeBievre, P. & Taylor, P.D.P. 1993: Table of the isotopic composition

of the elements. International Journal of Mass Spectrometry and Ion Processes 123, 149-166.

Fedo, C.M., Sircombe, K.N.& Rainbird, R.H. 2003. Detrtial zircon ana-lysis of the sedimentary record. In: Hanchar, J.M. & Hoskin, P.W.O. (eds.), Zircon. Reviews in Mineralogy and Geochemistry 53, 277– 303.

Gabrielsen, R.H., Steel, R.J. & Nøttvedt, A., 1995: Subtle traps in exten-sional terranes: A model with reference to the North Sea. Petro-leum Geoscience 1, 223-235.

Gabrielsen, R.H., Braathen, A., Olesen, O., Faleide, J.I., Kyrkjebø, R. & Redfield, T.F. 2005: Vertical movements in south-western Fennos-candia: a discussion of regions and processes from the Present to the Devonian. In: Wandås, B.T.G., Nystuen, J.P., Eide, E. & Grad-stein, F. (eds.): Onshore – Offshore Relationships on the North Atlan-tic Margin. Norwegian Petroleum Society Special Publication, 12, 1-28.

Gabrielsen, R.H., Faleide, J.I., Pascal, C., Braathen, A., Nystuen, J.P., Etzelmuller, B. & O’Donnell,S. 2010: Latest Caledonian to Present tectonomorphological development of southern Norway. Marine and Petroleum Geology 27, 709-723, doi: 10.1016/j.marpet-geo.2009.06.004.

Gee, D.G., Fossen, H., Henriksen, N. & Higgins, A.K. 2008: From the early Paleozoic platforms of Baltica and Laurentia to the Caledo-nide orogen of Scandinacvia and Greenland. Episodes 31, 1, 45-51.

Glennie, K.W. 1990: Rotliegend sediment distribution: a result of late Carboniferous movements. In: Hardman, R.F.P. & Brooks, J. (eds.): Tectonic Events Responsible for Britain’s Oil and Gas Reserves, Geological Society Special Publication No 55, pp 127-138.

Griffin, W.L., Pearson, N.J., Belousova, E., Jackson, S.E., van Achter-bergh, E., O’Reilly, S.Y. & Shee, S.R. 2000: The Hf isotope com-position of cratonic mantle: LAM-MC-ICPMS analysis of zircon megacrysts in kimberlites. Geochimica et Cosmochimica Acta 64, 133-147.

Griffin, W.L., Powell, W.J., Pearson, N.J. & O’Reilly, S.Y. 2008: GLIT-TER: data reduction software for laser ablation ICP-MS. In: Syl-vester, P. Laser Ablation ICP–MS in the Earth Sciences: Current Practices and Outstanding Issues. Mineralogical Association of Canada Short Course Series 40, 308-311.

Haug, L.E. 2007. Mantel og skorpekomponenter i Drammensgranit-ten, en LAM-ICPMS Lu-Hf isotopstudie av zirkon. Unpublished MSc thesis, Department of Geosciences, University of Oslo (in Norwegian ), 105 pp.

Heim, M., Skiöld, T. & Wolff, F.C. 1996: Geology, geochemistry and age of the ”Tricolor” granite and some other Proterozoic (TIB) gra-nitoids at Trysil, southeast Norway. Norsk Geologisk Tidsskrift 76, 45-54.

Heinonen, A.P., Andersen, T., Rämö, O.T. 2010. Re-evaluation of rapa-kivi petrogenesis: Source constraints from the Hf isotope composi-tion of zircon in the rapakivi granites and associated mafic rocks of southern Finland. Journal of Petrology 51, 1687-1709

Hjelmqvist, S. 1966: Beskrivning til berggrunnskarta över Koppar-bergs län. Med karta i skala 1: 200 000. Sveriges geologiska undersök-ning Ca 40, 1-217.

Hoskin P. W. O. & Schaltegger U. 2003: The composition of zircon and igneous and metamorphic petrogenesis. In: Hanchar, J.M. & Hoskin, P.W.O. (eds.), Zircon. Reviews in Mineralogy and Geoche-mistry 53, 27–62.

Högdahl, K., Andersson, U.B. & Eklund, O. 2004: The Transscandi-navian Igneous Belt (TIB) in Sweden; a review of its character and evolution. Geological Survey of Finland, Special Paper 37, 125 pp.

Høy T. & Bjørlykke, A. 1980: HAMAR, berggrunnskart 1916IV – M 1: 50 000. Norges Geologiske Undersøkelse, Trondheim.

Jackson, S.E., Pearson, N.J., Griffin, W.L. & Belousova, E.A. 2004: The application of laser ablation-inductively coupled plasma-mass spectrometry to in-situ U-Pb zircon geochronology. Chemical Geo-logy 211, 47-69.

evidence from detrital zircon in metasandstone. Precambrian Rese-arch 161, 231-249.

Bingen, B. & van Breemen, O. 1998: Tectonic regimes and terrane boundaries in the high-grade Sveconorwegian belt of SW Norway, inferred from U-Pb zircon geochronology and geochemical signa-ture of augen gneiss suites. Journal of the Geological Society, London 155, 143-154.

Bingen, B., Birkeland, A., Nordgulen, Ø. & Sigmond, E.M.O. 2001: Correlation of supracrustal sequences and origin of terranes in the Sveconorwegian orogen of SW Scandinavia: SIMS data on zircon in clastic metasediments. Precambrian Research 108, 293-318.

Bingen, B., Nordgulen, Ø., Sigmond, E.M.O., Tucker, R., Mansfeld, J., Högdahl, K. 2003: Relations between 1.19–1.13 Ga continental magmatism, sedimentation and metamorphism, Sveconorwegian province, S Norway. Precambrian Research 124, 215-240.

Bingen, B., Griffin, W.L., Torsvik, T.H. & Saeed, A. 2005a: Timing of Late Neoproterozoic glaciation on Baltica constrained by detrital zircon geochronology in the Hedmark Group, south-east Norway. Terra Nova 17, 250–258.

Bingen, B., Skår, Ø., Marker, M., Sigmond, E.M.O., Nordgulen, Ø., Ragnhildstveit, J., Mansfeld, J., Tucker, R.D. & Liégeois, J.-P. 2005b: Timing of continental building in the Sveconorwegian orogen, SW Scandinavia. Norwegian Journal of Geology 85, 87–116.

Bjørlykke, K. 1974a: Geochemical and mineralogical influence of Ordovician Island Arcs on epicontinental clastic sedimentation. A study of Lower Palaeozoic sedimentation in the Oslo Region, Nor-way. Sedimentology 21, 251-272.

Bjørlykke, K., 1978b: The eastern marginal zone of the Caledonide orogen in Norway. In: Caledonian – Appalachian Orogen of the North Atlantic Region, IGCP Project 27, Geological Survey of Canada, Paper 78-13, 49-55.

Black, L.P. & Gulson, B.L. 1978: The age of the Mud Tank Carbonatite, Strangways Range, Northern Territory. BMR Journal of Australian Geology and Geophysics 3, 227– 232.

Bouvier, A., Vervoort, J.D. & Patchett, P.J. 2008: The Lu-Hf and Sm-Nd isotopic composition of CHUR: Constraints from unequilibrated chondrites and implications for the bulk composition of terrestrial planets. Earth and Planetary Science Letters 273, 48-57.

Boynton, W.V. 1984: Cosmochemistry of the rare earth elements: Meteorite studies. In: Henderson, P. (ed.), Rare Earth Element Geo-chemistry. Developments in Geochemistry, 2. Elsevier, Amsterdam pp, 63-114.

Claesson, S., Huhma, H., Kinny, P.D. & Williams, I.S. 1993: Svecofen-nian detrital zircon ages implications for the Precambrian evolu-tion of the Baltic Shield. Precambrian Research 64, 109-130.

Corfu, F. & Dahlgren, S. 2008: Perovskite U-Pb ages and the Pb iso-topic composition of alkaline volcanism initiating the Permo-Carboniferous Oslo Rift. Earth and Planetary Science Letters 265, 256-269.

Dahlgren, S. 2010: The Larvik Plutonic Complex: The larvikite and nepheline syenite plutons and their pegmatites. In: A.O. Larsen (ed.), The Langesundsfjord. History, Geology, Pegmatites, Minerals. Bode Verlag GmbH, Salzhemmendorf, Germany, pp. 26-37.

Dahlgren, S. & Corfu, F. 2001: Northward sediment transport from the late Carboniferous Variscan Mountains: zircon evidence from the Oslo Rift, Norway. Journal of the Geological Society, London 158, 29-36.

Dahlgren, S., Corfu, F.,Heaman, L.M. 1996: U–Pb time constraints, and Hf and Pb source characteristics of the Larvik plutonic com-plex, Oslo Paleorift. Geodynamic and geochemical implications for the rift evolution. V.M. Goldschmidt Conference. Journal of Confe-rence Abstracts 1, 120.

Dahlgren, S., Corfu, F. & Heaman, L. 1998: Datering av plutoner og pegmatitter i Larvik pluton-kompleks, sydlige Oslo Graben, ved hjelp av U-Pb isotoper i zirkon og baddeleyitt. Norsk Bergverks-museum Skrift 14, 32-39 (in Norwegian).

Davies, N.S., Turner, P. & Sansom, I.J. 2005: A revised stratigraphy for the Ringerike Group (Upper Silurian, Oslo Region). Norwegian


ferous-Permian Oslo rift; Basin fill in relation to tectonic develop-ment. In: Embry, A.F., Beauchamp, B. & Glass, D.J. (eds): Pangea, Global environments and resources. Canadian Society of Petroleum Geologists Memoir 17, 175–198.

Patchett, P.J., Kouvo, O., Hedge, C.E. & Tatsumoto, M. 1981: Evolution of continental crust and mantle heterogeneity: Evidence from Hf isotopes. Contributions to Mineralogy and Petrology 78, 279-297.

Paul, J., Wemmer, K. & Wetzel, F. 2009: Keuper (Late Triassic) sedi-ments in Germany – indicators of rapid uplift of Caledonian rocks in southern Norway. Norwegian Journal of Geology 89, 193-202.

Pedersen, L.E., Heaman, L.M. & Holm, P.M. 1995: Further constraints on the temporal evolution of the Oslo Rift from precise U-Pb zir-con dating in the Siljan-Skrim area. Lithos 34, 301-315.

Pedersen, S., Andersen, T., Konnerup-Madsen, J. & Griffin, W.L. 2009: Recurrent mesoproterozoic continental magmatism in South-Cen-tral Norway. International Journal of Earth Science 98, 1151-1171.

Poprawa ,P., Slaupa, S., Stephenson, R.A., Lazauskiene, J. 1999: Late Vendian – Early Paleozoic tectonic evolution of the Baltic Basin: regional implications from subsidence analysis. Tectonophysics 314, 139-259.

Ramberg, I.B. & Larsen, B.T. 1978: Tectonomagmatic evolution. Nor-ges geologiske undersøkelse Bulletin 337, 55-74.

Røhr, T.S., Andersen, T., Dypvik, H., Embry, A.F. 2010. Detrital zir-con characteristics of the Lower Cretaceous Isachsen Formation, Sverdrup Basin; source constraints from age and Hf isotope data. Canadian Journal of Earth Science 47, 255-271.

Rohrman, M., van der Beek, P., Andriessen, P. & Cloetingh, S. 1995: Mesozoic-Cenozoic morphotectonic evolution of southern Nor-way: Neogene domal uplift inferred from apatite fission track ther-mochronology. Tectonics, 14, 704-718.

Rosa, D. R. N., Finch, A. A., Andersen, T., Inverno, C. M. C. 2009: U–Pb geochronology and Hf isotope ratios of magmatic zircons from the Iberian Pyrite Belt. Mineralogy and Petrology 95, 47-69.

Rosendahl, H., 1929: The porphyry-sandstone sequence in Brumund-dal: Norsk Geologisk Tidsskrift 10, 367–438.

Rukhlov, A.S. & Bell, K. 2010. Geochronology of carbonatites from the Canadian and Baltic Shields, and the Canadian Cordillera: clues to mantle evolution. Mineralogy and Petrology 98, 11-54.

Scherer, E.E., Münker, C. & Mezger, K. 2001: Calibration of the lute-tium-hafnium clock. Science 293, 683-687.

Scherer, E.E., Münker, C. & Mezger, K. 2007: The Lu-Hf systematics of meteorites: Consistent or not. Goldschmidt Conference Abstracts 2007, Geochimica et Cosmochimica Acta 71, 15S, A888.

Sliaupa, S., Poprowa, P., Lazauskiene, J. & Stephenson, R.A., 1997: The Palaeozoic subsidence history of the Baltic syneclise in Poland and Lithuenia. Geophysical Journal 19, 137-139.

Sircombe, K.N. & Stern, R.A., 2002: An investigation of artificial bia-sing in detrital zircon U-Pb geochronology due to magnetic sepa-ration in sample preparation. Geochemica et Cosmoschimica Acta 66, 2379–2397.

Sundvoll, B., Neumann, E.-R., Larsen, B.T. & Tuen, E., 1990: Age rela-tions among Oslo Rift magmatic rocks: implications for tectonic and magmatic modelling. Tectonophysics 178, 67-87.

Söderlund, U., Patchett, J.P., Vervoort, J.D. & Isachsen, C.E. 2004: The 176Lu decay constant determined by Lu-Hf and U-Pb isotope system atics of Precambrian mafic intrusions. Earth and Planetary Science Letters 219, 311-324.

Thorslund, P. 1960. The Cambro-Silurian. Sveriges Geologiska Undersökning Ser. Ba 16, 69-110.

Turner, P. & Whitaker, J.H.McD. 1976. Petrology and provenance of late Silurian fluviatile sandstones from the Ringerike Group of Norway. Sedimentary Geology 16, 45-68.

Vander Auwera, J., Bogaerts, M., Liégeois, J.-P., Demaiffe, D., Wilmart, E., Bolle, O. & Duchesne, J.C. 2003: Derivation of the 1.0-0.9 Ga ferro-potassic A-type granitoids of southern Norway by extreme differentiation from basic magmas. Precambrian Research 124, 107-148.

Wiedenbeck, M., Alle, P., Corfu, F., Griffin, W.L., Meier, M., Oberli,

Jeppson, L. & Laufeld, S. 1986: The late Silurian Öved-Ramsåsa Group in Skåne, south Sweden. Sveriges geologiska undersökning Ca 58, 1-58.

Kinney, P.D. & Maas, R. 2003: Lu–Hf and Sm–Nd isotope systems in zircon. In: Hanchar, J.M. & Hoskin, P.W.O. (eds.), Zircon. Reviews in Mineraleralogy and Geochemistry 53, 327–341.

Kohonen, J. & Rämö, O.T. 2005: Sedimentary rocks, diabases, and late cratonic evolution. In: Lehtinen, M., Nurmi, P.A. & Rämö, O.T. (eds.): Precambrian Geology og Finland - Key to the evolution of the Fennoscandian Shield. Developments in Precambrian Geology, Elsevier, Amsterdam, 14, 563-604.

Lahtinen, R., Huhma, H. & Kousa, J. 2002: Contrasting source com-ponents of the Paleoproterozoic Svecofennian metasediments: Detrital zircon U–Pb, Sm–Nd and geochemical data. Precambrian Research 116, 81–109

Lamminen, J. & Köykkä, J. 2010: The provenance and evolution of the Rjukan Rift Basin, Telemark, south Norway: The shift from a rift basin to an epicontinental sea along a Mesoproterozoic superconti-nent. Precambrian Research 181, 129-149.

Lamminen, J., Nystuen, J.P & Andersen, T. 2008: U-Pb and Lu-Hf zir-con data from the Rosten Formation, south Norway: characteri-zing the western margin of Baltica before the breakup of Rodinia. Abstracts, 33rd IGC, Lillestrøm, Norway, August 2008, Symposium EUR01 - Three billion years of geological history of the Baltic Shield and its shelf.

Lamminen, J., Nystuen, J.P, Andersen, T. 2009: U-Pb ages and Lu-Hf isotopes of granitoid clasts and basement rocks of the Hedmark Group: implications for structural setting of the Hedmark Basin at the Baltoscandian margin. Abstracts, NGF Winter Conference, Bergen, Jan. 2009. Norsk Geologisk Forening Abstracts and Proceed-ings 2009, 1, 60-61.

Larsen, B.T., Olaussen, S., Sundvoll, B. & Heeremans, M. 2008: The Permo-Carboniferous Oslo Rift through six stages and 65 million years. Episodes 31, 1, 52-58.

Larson, S.Å. & Berglund, J. 1992: A chronological subdivision of the Transscandinavian Igneous Belt – three magmatic episodes? Geolog iska Föreningens i Stockholm Förhandlingar 114, 459-461.

Lauri, L.S., Andersen, T., Hölttä, P., Huhma, H. & Graham, S. 2011: Evolution of the Archaean Karelian province in the Fenno scan-dian Shield in the light of U–Pb zircon ages and Sm–Nd and Lu–Hf isotope systematics. Journal of the Geological Society, London 168, 201-218 (in press).

Lazauskiene, J., Stephenson,R., Sliaupa,S. & van Wees,J.-D. 2002: 3-D flexural modeling of the Silurian Baltic Basin. Tectonophysics, 346, 115-135.

Lundqvist, T. & Persson, P.-O. 1999: Geochronology of porphyries and related rocks in northern and western Dalarna, south-central Sweden. GFF 122, 307-322

McCann, T. 1998: The Rotliegend of the NE German Basin: back-ground and prospectivity. Petroleum Geoscience 4, 17-27.

McDonough, W.F., Sun, S.-s. 1995: The composition of the Earth. Che-mical Geology 120, 223-253.

Neumann, E.-R., Wilson, M., Heeremans, M., Spencer, E.A., Obst, K., Timmerman, M.J., & Kirstein, L. 2004: Carboniferous-Permian rif-ting and magmatism in southern Scandinavia and northern Ger-many: a review. In: Wilson, M., Neumann, E.R., Davies, G.R., Tim-merman, M.J., Heeremans, M. & Larsen, B.T. (eds). Permo-Carbo-niferous Magmatism and Rifting in Europe (pp. 11-40). Geological Society, London, Special Publications, 223, 11-40.

Nystuen, J.P., Andresen, A., Kumpulainen, R.A., Siedlecka, A. 2008: Neoproterozoic basin evolution in Fennoscandia, East Greenland and Svabard. Episodes 31, 1, 35-43.

O’Brien, H.E., Peltonen, P., Vartiainen, H. 2005: Kimberlites, carbona-tites and alkaline rocks. In: Lehtinen, M., Nurmi, P.A. & Rämö, O.T. (eds.) Precambrian geology of Finland. Key to the evolution of the Fennoscandian Shield. Elsevier, Amsterdam: Developments in Pre-cambrian Geology 14, 605-644.

Olaussen, S., Larsen, B.T. and Steel, R. 1994: The Upper Carboni-


F., Von Quadt, A., Roddick, J.C. & Spiegel, W. 1995: Three natural zircon standards for U-Th-Pb, Lu-Hf, trace element and REE ana-lyses. Geostandards Newsletter 19, 1, 1-23.

Worsley, D., Aarhus, N., Bassett, M.G., Howe, M.P.A., Mørk, A. & Olaussen, S. 1983: The Silurian succession of the Oslo region. Norges Geologiske Undersøkelse, 384, 1-57.

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