Lars Eivind Augland

• Zuchuat, Valentin; Janocha, Julian; Brooks, Hannah L.; Buchwald, Stella Z.; Beaty, Brian & Tarhan, Lidya G. [Show all 13 contributors for this article] (2026). New insights on the depositional environment and dynamics of the lowermost Triassic in Svalbard: linking the Sørkapp-Hornsund High to western and central Spitsbergen. Sedimentologika. 4(1). doi: 10.57035/journals/sdk.2026.e41.2413. Full text in Research Archive Show summary

  The area now known as the Barents Shelf region was strongly impacted by the End-Permian Mass Extinction and a fundamental reorganisation of source-to-sink systems along the northern margin of Pangaea. Here we integrate new sedimentological, ichnological, chemostratigraphic, and provenance data from western Spitsbergen, collected at Festningen, Reinodden, and the Sørkapp-Hornsund High (Hornsundneset, southern Spitsbergen), to reconstruct the timing and drivers of Early Triassic basin evolution. At Festningen and Reinodden, the sharp but conformable transition from Permian spiculitic Kapp Starostin Formation strata to siliciclastic mudstones and sandstones of the Lower Triassic Vardebukta Formation coincides with the onset of the negative δ13Corg excursion. The Vardebukta Formation preserves seven stacked transgressive–regressive packages within an Induan-age interval of ca 1.2 to 1.6 Myr. Individual cycle durations (ca 177 to 225 kyr) are incompatible with a single dominant Milankovitch component and instead suggest bundling of orbital frequencies and/or strong autogenic modulation of accommodation and sediment supply. On the Sørkapp-Hornsund High, a 75 Myr hiatus above Mississippian continental deposits is terminated by a 10 to 15 cm thick bentonitic tephra bed linked to the Siberian Traps Large Igneous Province. This is overlain by Induan-age polymictic alluvial-fan and ephemeral braided-river conglomerates (Brevassfjellet Beds), on which limited but recurrent vegetation cover developed. Detrital-zircon age spectra from the conglomerates closely match published data from the Vardebukta Formation at Festningen and the Induan-age Parish Bjerg Formation in Greenland, indicating a shared north Greenland Caledonian source and direct sediment routing during the latest Permian and earliest Triassic. These continental conglomerates are capped by fossiliferous shallow-marine limestones of Dienerian age, which are then overlain by the coarsening-upward shelfal succession of the Vardbukta Formation. The timing of Dienerian flooding of the Sørkapp-Hornsund High is not aligned with any individual transgressive-regressive package in the Vardebukta Formation, implying that local tectonic subsidence of a promontory-like high, rather than eustatic rise, governed its transgression. This research refines the palaeogeographical and tectonostratigraphical evolution of the northern margin of Pangaea during the latest Permian and earliest Triassic.

• Jones, Morgan Thomas; Augland, Lars Eivind; Ovtcharova, Maria; Stokke, Ella Wulfsberg; Ganerød, Morgan & Planke, Sverre (2025). New constraints on the absolute age and duration of the Paleocene – Eocene Thermal Maximum (PETM) from ash layer +19 in Denmark. Earth and Planetary Science Letters. ISSN 0012-821X. 671. doi: 10.1016/j.epsl.2025.119643. Full text in Research Archive Show summary

  Precise age constraints for the onset and duration of the Paleocene–Eocene Thermal Maximum (PETM) are essential for understanding the mechanisms that triggered and sustained this major climate perturbation. However, establishing a precise PETM geochronology is complicated by uncertainties in orbital tuning and a current lack of precise radiometrically dated marker horizons. An early Eocene rhyolitic ash layer named +19 is a promising marker horizon due to its distinct geochemistry, its occurrence in key offshore archives, and well-preserved outcrops in Denmark such as Stolleklint, where it conformably overlies PETM strata. We present a new high-precision U-Pb zircon age of 55.331 ± 0.053/(0.060)/[0.080] Ma for ash +19, supported by a new Ar-Ar age of 55.424 ± 0.115/(0.116)/[0.320] Ma within uncertainty. The ash +19 U-Pb age enables direct comparison with ash SB01–1 in Svalbard that was erupted during the PETM carbon isotope excursion (CIE), yielding a 454 ± 90 kyr interval between the two layers. This provides a robust geochronological link from the PETM to ash +19 that is independent of stratigraphic interpretations. Using end-member PETM durations (94–170 kyr), we estimate the time between the PETM onset and ash +19 as 528–604 ± 102 kyr, which is significantly shorter than the 862 ± 20 kyr interval derived from astronomical tuning. Adopting the longer helium isotope-based PETM duration yields an onset age of 55.935 ± 0.102 Ma, with a CIE recovery end at 55.700 Ma. A shorter PETM duration requires a younger PETM onset age. The positive ash series in Denmark, correlating with the offshore Balder Formation, is now constrained to a 250 kyr interval between 55.367 and 55.117 ± 0.080 Ma. This refined age model provides a robust framework for testing and improving early Eocene astronomical time scales.

• Smyrak-Sikora, Aleksandra; Betlem, Peter; Engelschiøn, Victoria Sjøholt; Foster, William J.; Grundvåg, Sten-Andreas & Jelby, Mads Engholm [Show all 26 contributors for this article] (2025). Phanerozoic paleoenvironmental and paleoclimatic evolution in Svalbard. Climate of the Past. ISSN 1814-9324. 21(11), p. 2133–2187. doi: 10.5194/cp-21-2133-2025. Full text in Research Archive Show summary

  Sedimentary rocks can provide information about the Earth paleoenvironment and are studied extensively to understand the causes and consequences of global climate changes in deep time. They facilitate long-time perspectives that constrain climate models and provide analogues for how Earth systems may respond to, and recover from, intervals of profound environmental change, including projected anthropogenic change. The Norwegian Svalbard archipelago offers an extensive Phanerozoic stratigraphic record that reflects the geological evolution of the northern flanks of continental assemblages that include Laurentia, Eurasia, and Pangea. Svalbard's Phanerozoic sedimentary and paleoclimatic archive is controlled largely by Svalbard's overall northward plate-tectonic motion from equatorial to high latitudes but also by regional to local formation of topography and basins in response to long-term plate reorganization, as well as the near- and far-field influence of large igneous province activity on the tectono-stratigraphic and paleoclimatic development. Various sedimentary and geochemical proxies, such as bentonite beds and carbon isotope excursions associated with the far-reaching environmental effects of the Siberian Traps, the High Arctic Large Igneous Province, and the North Atlantic Igneous Province, are present in Svalbard's near complete geological record. As such, Svalbard is unique in that these and numerous other global environmental perturbations are recorded within a relatively restricted study area, with most of the key events preserved and recorded in easily accessible drill cores and well-exposed outcrop sections. Here we review deep-time paleoenvironmental and paleoclimate research in Svalbard by summarizing 148 peer-reviewed scientific articles. The review builds on the well-established tectono-stratigraphic and lithostratigraphic framework, as well as state-of-the art environmental reconstructions, to provide insights into the Earth system during the Phanerozoic northward drift of Svalbard and the many major biotic crises in the geological past. We focus on globally significant events including (i) the expansion of Devonian vegetation, (ii) the Carboniferous–Permian response to icehouse conditions during the Late Paleozoic Ice Age (LPIA), (iii) the End-Permian Mass Extinction (EPME) and the subsequent Triassic recovery, the (iv) Carnian Pluvial Episode, (v) Jurassic–Early Cretaceous climate perturbations including the Volgian Isotopic Carbon Excursion (VOICE) and the Aptian Ocean Anoxic Event 1a (OAE1a), and (vi) the Paleocene–Eocene Thermal Maximum (PETM). We present and synthesize existing core and outcrop data that preserve biological and geochemical proxies and climate-sensitive sedimentary facies that reflect environmental change in terrestrial and marine settings. Finally, we discuss the Phanerozoic climate recorded in Svalbard and its role in providing high-latitude calibration points for several global paleoclimate events to provide a higher-latitude perspective to complement the dominance of mid- and low-latitude locations and datasets in the literature.

• Millett, J.M.; Jolley, D.W.; Hole, M.J.; Augland, Lars Eivind; Pugsley, J.H. & McLeod, G.W. [Show all 7 contributors for this article] (2024). High-precision U/Pb zircon dating of explosive volcanism in an early bi-modal volcano-sedimentary sequence from the Isle of Mull, North Atlantic Igneous Province. Lithos. ISSN 0024-4937. 482-483. doi: 10.1016/j.lithos.2024.107729. Full text in Research Archive Show summary

  The North Atlantic Igneous Province (NAIP) forms one of the best studied Large Igneous Provinces (LIP) on the planet, however, significant uncertainties regarding the age and nature of the early onset of volcanism across the province remain. In order to better understand the onset and timing of volcanism within the NAIP, we present a new study of the mixed volcano-sedimentary deposits exposed at the base of the Isle of Mull lava pile, Inner Hebrides, Scotland. The study area comprises organic rich estuarine sediments, intimately mixed and interdigitated with bi-modal composition volcaniclastic and pyroclastic interlayers, including a prominent stratigraphically constrained c. 30 cm thick water-lain rhyolitic ignimbrite. Pristine magmatic zircons liberated from the ignimbrite reveal a high precision Usingle bondPb age of 62.035 ± 0.041 Ma (2σ) giving a robust age for early volcanism in this part of the province. Field observations reveal evidence for mafic phreatomagmatic eruptive deposits both above and below the rhyolite documenting the bimodal explosive nature of the initial magmatism in this area and, importantly, that mafic magmatism initiated before the dated unit. The bi-modal explosive eruptions periodically inundated an otherwise quiet and low energy Danian aged estuarine environment prior to its inundation with lava as magmatism took hold in the region.

• Abdallah, Randa Ben; Abdelmalak, Mohamed Mansour; Augland, Lars Eivind; Lazaar, Sonia; Polteau, Stephane & Callegaro, Sara [Show all 7 contributors for this article] (2024). Miocene magmatism in Northern Tunisia and its geodynamic implications. Mediterranean Geoscience Reviews. ISSN 2661-863X. 6, p. 269–292. doi: 10.1007/s42990-024-00139-1. Full text in Research Archive Show summary

  The Nefza igneous rocks in Northern Tunisia belong to the Miocene magmatic belt extending from Northern Tunisia to Morocco and consist mainly of Serravallian–Tortonian granodiorite and rhyodacite (~ 14–8 Ma) and Messinian basalts (~ 8–6 Ma). Differences in geochemical composition between units have been interpreted to be the result of geodynamic processes in the upper mantle below the Western Mediterranean area, but their implications for Northern Tunisia are unclear due to limited data. In this contribution, we present an updated geodynamic model for Northern Tunisia based on new petrographic and whole-rock geochemical results from the Nefza magmatic suite from outcrop and OB45 drill core samples. Petrographic observations show that rhyodacites display a microlithic texture with quartz, plagioclase, K-feldspar, biotite, and glass, whilst granodiorite contains plagioclase, quartz and exhibits fine-grained texture with a 2–3 mm crystal size. The Nefza magmatic rocks are overprinted by multiple weathering and alteration processes with loss of ignition (LOI) ranging between 0.88 and more than 5 wt%. The linear relationships between mobile elements (Ca, Na, P, K, Mg, Si), large-ion lithophile elements (LILE), and LOI suggest element mobilisation during alteration. Major and trace element compositions show the Nefza magmatic rocks plot in the rhyolite, dacite, and trachydacite fields for felsic rocks and plot in the basalt and trachybasalt fields for mafic rocks. Granodiorite and rhyodacite rocks exhibit negative Eu anomalies and a LILE enrichment (Rb, Ba, Pb) relative to high-field-strength elements (HFSE: Nb, Ta, Hf, Zr, REE). Mafic rocks enriched in LILE show geochemical characteristics between calc-alkaline and alkaline trends. Comparison with nearby regions suggests that the generation of calc-alkaline magmas resulted from the partial melting of the lithospheric mantle due to slab break-off or tearing in Eastern Algeria. The upward flow of asthenospheric material through the widening tear in the sinking slab leads to partial melting of the mantle and shallowing of the lithosphere–asthenosphere boundary, ultimately leading to the formation of alkaline magma. The Nefza geochemical variations underscore Mediterranean upper mantle heterogeneity, offering crucial insights into Mediterranean geodynamics. More studies are needed to constrain mantle dynamics and the region’s complex geological history.

• Keyser, William Mark; Müller, Axel; Augland, Lars Eivind & Steiner, Ralf (2024). Rare-metal halos of lithium pegmatite at the Wolfsberg deposit, Austria, and their implications for exploration. Ore Geology Reviews. ISSN 0169-1368. 171. doi: 10.1016/j.oregeorev.2024.106179. Full text in Research Archive Show summary

  The Austroalpine Unit Pegmatite Province (AUPP) in the eastern European Alps hosts abundant Permian-aged, variably rare-metal-enriched pegmatite bodies. However, only a small number containing spodumene [LiAlSi2O6] have been discovered. Here, we characterize three drill cores from the AUPP’s largest spodumene pegmatite resource, the Wolfsberg deposit (Austria), to determine the extent of rare-metal halo formation within different host rock types generated by pegmatite-derived fluids and their applicability to spodumene pegmatite exploration. The halos in both mica schist and amphibolite host rocks, as quantified via whole-rock mass-balance calculations, are characterized by enrichments in Li, Cs, Sn, Rb and Tl, amongst others, elements which were highly mobile during initial interactions between pegmatite-derived fluids and host rocks. The concentrations of these elements within the halos can be several times that present in unaltered host rock. They are most enriched in altered host rock interbedded or at the contacts with pegmatite, and decrease with distance from pegmatite to a distance of at least 4 m in mica schist and <3 m in amphibolite. Lithium, and in mica schist, Cs, have the most consistent and furthest extending halos, with respective concentrations of >590 ppm and >40 ppm in mica schist, and >390 ppm Li in amphibolite indicating proximity to spodumene pegmatite. An ID-TIMS U-Pb titanite age of ca. 103 Ma derived from a rare-metal-enriched amphibolite within the alteration halo reflects recrystallization of the Permian protolith during the Cretaceous Alpine orogeny and indicates preservation of the original pegmatite signature through eclogite-facies metamorphism. Recognition of rare-metal halos surrounding pegmatite at Wolfsberg serves as a potential geochemical exploration tool for spodumene pegmatite within the AUPP and may be applicable to other regions.

• Condon, Dan; Schoene, Blair; Schmitz, Mark; Schaltegger, Urs; Ickert, Ryan B. & Amelin, Yuri [Show all 37 contributors for this article] (2024). Recommendations for the reporting and interpretation of isotope dilution U-Pb geochronological information. Geological Society of America Bulletin. ISSN 0016-7606. 136(9-10), p. 4233–4251. doi: 10.1130/B37321.1. Full text in Research Archive Show summary

  U-Pb geochronology by isotope dilution–thermal ionization mass spectrometry (ID-TIMS) has the potential to be the most precise and accurate of the deep time chronometers, especially when applied to high-U minerals such as zircon. Continued analytical improvements have made this technique capable of regularly achieving better than 0.1% precision and accuracy of dates from commonly occurring high-U minerals across a wide range of geological ages and settings. To help maximize the long-term utility of published results, we present and discuss some recommendations for reporting ID-TIMS U-Pb geochronological data and associated metadata in accordance with accepted principles of data management. Further, given that the accuracy of reported ages typically depends on the interpretation applied to a set of individual dates, we discuss strategies for data interpretation. We anticipate that this paper will serve as an instructive guide for geologists who are publishing ID-TIMS U-Pb data, for laboratories generating the data, the wider geoscience community who use such data, and also editors of journals who wish to be informed about community standards. Combined, our recommendations should increase the utility, veracity, versatility, and “half-life” of ID-TIMS U-Pb geochronological data.

• Lisica, Karlo; Augland, Lars Eivind; Stevenson, John A.; Jerram, Dougal Alexander; Beresford-Browne, Adam & Jones, Morgan T. (2024). High-precision U–Pb geochronology of the Lundy igneous complex: implications for North Atlantic volcanism and the far-field Paleocene–Eocene ash record. Journal of the Geological Society. ISSN 0016-7649. 182(1). doi: 10.1144/jgs2023-140. Full text in Research Archive Show summary

  The Lundy Island (Bristol Channel, UK) granite is a felsic expression of the southernmost igneous centre of the North Atlantic Igneous Province that emplaced millions of cubic kilometres of magma during the Paleogene. The granite's distinctive S-type, peraluminous, two-mica ± garnet ± tourmaline composition has led to the hypothesis that eruptions from the Lundy volcanic centre may be the source of thick felsic ash layers within the early Eocene Fur Formation (Denmark) that act as key marker horizons for the onset and duration of the Paleocene–Eocene Thermal Maximum. This paper presents high-precision zircon U–Pb emplacement ages of 57.24 ± 0.11/0.12/0.13 Ma for the granite and 55.970 ± 0.021/0.030/0.070 Ma for a felsic ‘lundyite’ dyke. Trace and rare earth element patterns indicate close similarities between late-stage Lundy activity and ash layer −33 in Denmark. This ash layer was deposited during the Paleocene–Eocene Thermal Maximum carbon isotope excursion, suggesting that the Lundy volcanic centre is likely to be the source of this key ash horizon and that magmatism at Lundy likely continued into the early Eocene.

• Galland, Olivier; Villar, Héctor J.; Mescua, José; Jerram, Dougal Alexander; Messager, Gregoire Eugene Philippe & Medialdea, Adrian [Show all 11 contributors for this article] (2024). Structural control of igneous intrusions on fluid migration in sedimentary basins: the case study of large bitumen seeps at Cerro Alquitrán and Cerro La Paloma, northern Neuquén Basin, Argentina. Geological Society Special Publication. ISSN 0305-8719. 547(1), p. 231–259. doi: 10.1144/SP547-2023-115. Full text in Research Archive
• Król, Piotr; Kusiak, Monika A.; Dunkley, Daniel J.; Whitehouse, Martin J.; Wilde, Simon A. & Augland, Lars Eivind (2023). The record of geological processes in zircon from polymetamorphosed orthogneisses from the Napier Mountains, Napier Complex, East Antarctica. Journal of Mineralogical and Petrological Sciences. ISSN 1345-6296. 118. doi: 10.2465/JMPS.230419. Full text in Research Archive
• Rogov, M.A.; Panchenko, I.V.; Augland, Lars Eivind; Ershova, V.B. & Yashunsky, V.Yu. (2023). The first CA-ID-TIMS U-Pb dating of the Tithonian/Berriasian boundary beds in a Boreal succession. Gondwana Research. ISSN 1342-937X. 118, p. 165–173. doi: 10.1016/j.gr.2023.02.010. Full text in Research Archive
• Müller, Axel; Romer, Rolf L.; Augland, Lars Eivind; Zhou, Haoyang; Rosing-Schow, Nanna & Spratt, John [Show all 7 contributors for this article] (2022). Two-stage regional rare-element pegmatite formation at Tysfjord, Norway: implications for the timing of late Svecofennian and late Caledonian high-temperature events. International journal of earth sciences. ISSN 1437-3254. 111, p. 987–1007. doi: 10.1007/s00531-022-02166-5. Full text in Research Archive Show summary

  Abstract Pegmatite fields within granite plutons are commonly considered to have formed from residual melts of their host. This is not always true as demonstrated by the Tysfjord granite gneiss and its two groups of pegmatites. The Tysfjord granite gneiss, exposed in a tectonic window of the Caledonides of northern Norway, is part of the transscandinavian igneous belt (TIB) that includes several phases of granitic magmatism. In the northern Hamarøy area (Drag-Finnøy), where most rare-element pegmatites occur, Paleoproterozoic and metamorphosed Group 1 allanite–(Ce)–fluorite metapegmatites have similar bulk rock chemical composition as the TIB granite gneiss rocks, indicating that these pegmatites are residual melts. Group 1 metapegmatites, which are up to 400 m in size, are among the largest known intra-plutonic pegmatites with Nb–Y–F (NYF) signature. The formation of these unusually large granite-hosted NYF pegmatites may have been facilitated by the overall high F content of TIB granite gneisses. Undeformed Group 2 amazonite–tourmaline pegmatites yield columbite and zircon U–Pb ages in the range 400–379 Ma. These pegmatites are interpreted to be anatectic melts that formed from the partial melting of Tysfjord granite gneiss. Group 2 pegmatites, including those from Træna Island and the Sjona tectonic window (400 and 414 Ma), formed during late Caledonian ductile shearing and incipient unroofing of the central Scandinavian Caledonides and record progressively younger ages of this event from SW to NE.

• Bakhsh, Rami A.; Ali, Kamal A.; Zoheir, Basem A.; Augland, Lars Eivind; Ahmed, Ahmed H. & Stein, Holly Jayne (2022). Geochemical and geochronological constraints on the gold-sulfide mineralization and host granitoid rocks in the Bulghah and Al-Maham prospects, central Arabian Shield, Saudi Arabia. Journal of Asian Earth Sciences. ISSN 1367-9120. 223. doi: 10.1016/j.jseaes.2021.105004. Full text in Research Archive
• Zhou, Haoyang; Müller, Axel; Augland, Lars Eivind; Kristoffersen, Magnus & Erambert, Muriel (2022). Titanite links rare-element (meta-)pegmatite mineralization to Caledonian metamorphism. Geochimica et Cosmochimica Acta. ISSN 0016-7037. 332, p. 285–306. doi: 10.1016/j.gca.2022.06.014. Full text in Research Archive Show summary

  The metamorphic reworking of mineralized pegmatites during orogenesis remains unclear, making the genesis and the tectonomagmatic significance of pegmatite mineralization obscure. This study demonstrates the multiple utilities of titanite geochemistry in establishing the Caledonian metamorphic evolution of the world’s largest intra-plutonic Nb-Y-F pegmatites in the Paleoproterozoic host rocks in Tysfjord, Northern Norway. A combination of titanite-specific barometry, Zr-in-titanite thermobarometry, and titanite U-Pb geochronology yields peak metamorphism of ∼12 kbar and 730–750 °C at ∼410 Ma for the host rocks and the largest metamorphosed Paleoproterozoic pegmatite (meta-pegmatite) in the region. In relation to published U-Pb ages of 410–400 Ma for other regional meta-pegmatites, interpreted as Caledonian overprinting here, we argue that the Paleoproterozoic pegmatite protoliths have undergone metamorphism analogous to the host rocks, which was caused by allochthonous nappe stacking late in the Caledonian collisional orogeny (∼440–400 Ma). Published formation ages of ∼400–380 Ma for the regional undeformed pegmatites are 10–30 Ma younger than the peak metamorphism, supporting an anatectic link to the Caledonian post-collisional extension. The Caledonian orogeny led to strong shearing of preexisting pegmatite bodies and resetting of trace elements and U-Pb isotopic systems of the constituent minerals via mineral re-crystallization, inheritance of Pb isotopic components, and element diffusion. This cautions against the interpretation of meta-pegmatite-derived ages and geochemical information in tectonomagmatic terranes without detailed textural investigation.

• Bastos, Lucas Pinto Heckert; Rodrigues, René; Pereira, Egberto; Bergamaschi, Sergio; Alferes, Carmen Lucia Ferreira & Augland, Lars Eivind [Show all 9 contributors for this article] (2021). The birth and demise of the vast epicontinental Permian Irati-Whitehill sea: Evidence from organic geochemistry, geochronology, and paleogeography. Palaeogeography, Palaeoclimatology, Palaeoecology. ISSN 0031-0182. 562. doi: 10.1016/j.palaeo.2020.110103. Full text in Research Archive
• Warvik, Kenneth; Ringstad, Håkon Blaker; Augland, Lars Eivind; Corfu, Fernando & Gabrielsen, Roy Helge (2021). The Revsegg and Kvitenut allochthons, Scandinavian Caledonides: origins and evolution in the Caledonian Wilson cycle. Journal of the Geological Society. ISSN 0016-7649. 179(3). doi: 10.1144/jgs2021-062. Full text in Research Archive
• Zuchuat, Valentin; Sleveland, Arve; Twitchett, Richard; Svensen, Henrik; Turner, Holly & Augland, Lars Eivind [Show all 12 contributors for this article] (2020). A new high-resolution stratigraphic and palaeoenvironmental record spanning the End-Permian Mass Extinction and its aftermath in central Spitsbergen, Svalbard. Palaeogeography, Palaeoclimatology, Palaeoecology. ISSN 0031-0182. 554. doi: 10.1016/j.palaeo.2020.109732. Full text in Research Archive Show summary

  Research on the Permian-Triassic boundary (PTB) along the northern margins of Pangaea (exposed today in the Arctic region) has been heavily reliant on field observations, where data resolution was consequently determined by outcrop condition and accessibility. Core drilling in central Spitsbergen allowed for a near-complete recovery of two ~90 m cores through the PTB. Analyses of the core and nearby outcrops include stratigraphic logging and sampling, XRF scanning, petrography, biostratigraphy, isotope geochemistry, and geochronology. The First Appearance Datum (FAD) of H. parvus in Svalbard places the base of the Triassic ca. 4 m above the base of the Vikinghøgda Formation, and ca. 2.50 m above the End-Permian Mass Extinction (EPME) and its associated sharp negative δ13C. The PTB therefore falls within the Reduviasporonites chalastus Assemblage Zone in Svalbard. Precise U-Pb TIMS dating of two zircon crystals in a tephra layer just above the first documented Hindeodus parvus in Svalbard gives an age of 252.13 ± 0.62 Ma. High-resolution palaeoenvironmental proxies, including Si/kcps (kilo counts per second), Zr/Rb, K/Ti, Fe/K, and V/Cr, indicate a transition towards a more arid climate in the earliest Triassic, contemporaneous with prolonged bottom-water dysoxic/anoxic conditions, following an increase in volcanic activity in the Late Permian. Statistical analysis of Zr/Rb, K/Ti and V/Cr elemental ratios suggests that the system was impacted by long-eccentricity (400 kyr) cyclicity. The δ13C excursion in organic carbon (δ13Corg) record signals a large negative carbon isotope excursion (CIE) associated with the mass extinction event, but also records a second, smaller negative CIE ca. 22 m above this interval. This younger δ13Corg excursion correlates to similar CIEs in the Dienerian (late Induan) records of other sections, notably in the Tethys Ocean, which have been interpreted as recording a small biotic crisis during the post-extinction recovery. Evidence of this negative CIE in Spitsbergen suggests that the Dienerian crisis may have been global in extent. The negative δ13Corg values are associated with evidence for dysoxia or anoxia in the core, and the occurrence of tephra layers in the same interval suggests a possible connection between the Dienerian crisis and a discrete episode of volcanic activity.

• Dalslåen, Bjørgunn Heggem; Gasser, Deta; Grenne, Tor; Augland, Lars Eivind & Corfu, Fernando (2020). Ordovician shoshonitic to ultrapotassic volcanism in the central Norwegian Caledonides: The result of sediment subduction, mantle metasomatism and mantle partial melting. Lithos. ISSN 0024-4937. 356-357. doi: 10.1016/j.lithos.2020.105372. Full text in Research Archive Show summary

  Shoshonitic to ultrapotassic, mantle-derived volcanic rocks found within certain accretionary and collisional settings have trace element patterns comparable to those of common arc-related rocks, but with extreme enrichments in highly incompatible elements. Such rocks, previously unknown in the Scandinavian Caledonides, have been discovered in the Oppdal area in the Trondheim Nappe Complex, central Norway. The volcanic rocks are part of the Skarvatnet unit, which consists of (1) the Kinna volcanic succession, (2) the Storgruvpiken rhyolite, and (3) the Skaret conglomeratic succession. The Kinna volcanic succession is interpreted as consisting mainly of submarine pyroclastic flows. A trachytic bed from within this succession is dated to 474 ± 1 Ma. The Storgruvpiken rhyolite is interpreted as a shallow, subvolcanic intrusion or volcanic dome, and is dated to 470 ± 1 Ma. The Skaret conglomerates were deposited in a shallow-marine, tectonically active setting post-dating the Storgruvpiken rhyolite. The Kinna volcanic succession is highly enriched in Th, U, Pb and LREE, with trace element signatures remarkably similar to high-K to ultrapotassic rocks of the Alpine-Himalayan and other orogenic belts. By analogy with these recent examples, the Kinna volcanic succession is interpreted as the result of a two-stage process: (1) subduction and partial melting of continent-derived material caused extensive metasomatism of the overlying mantle wedge, (2) partial melting of this heterogeneous mantle source produced the highly enriched mantle melts. The Storgruvpiken rhyolite, particularly enriched in beryllium, is interpreted as the result of partial melting of Kinna-type rocks at depth. The Skarvatnet unit is interpreted as the result of a complex tectonic evolution at the margin of the Iapetus Ocean, involving the following stages: (1) intra-oceanic subduction, producing the Løkken-Vassfjellet-Bymarka ophiolite at 487–480 Ma, followed by (2) the arrival of the Laurentian margin or an associated micro-continent at ca. 480 Ma, leading to the subduction of large amounts of continent-derived material and subsequent metasomatism of the overlying mantle wedge, (3) arc-continent-collision and slab retreat/slab break-off, causing an intermittent phase of mantle-derived, highly enriched magmatism preserved as the Kinna volcanic succession and the Storgruvpiken rhyolite at 475–470 Ma.

• Lundmark, Anders Mattias; Augland, Lars Eivind & Jørgensen, Simen V. (2020). Digital fieldwork with Fieldmove - how do digital tools influence geoscience students’ learning experience in the field? Journal of Geography in Higher Education. ISSN 0309-8265. 44(3), p. 427–440. doi: 10.1080/03098265.2020.1712685. Full text in Research Archive Show summary

  Third year geoscience students were introduced to digital tools for fieldwork, Fieldmove on iPads, in a capstone field mapping course at Oslo University, Norway. Despite little prior experience with digital tools for fieldwork, they became independent Fieldmove users in a few hours. They self-report positive cognitive impacts, including positive effects on quality of fieldwork, maps and reports. However, submitted course material suggest students achieved similar levels of understanding with and without digital tools. We hypothesize that students’ confidence in their work increases when supported by digital tools, however, they may also overrate their proficiency due to the ease of collecting large data sets, and the professional look of the digital outputs. Students report both positive and negative effects on teamwork; observations suggest this reflects sharing of devices rather than use of digital tools per se. The students also report pronounced positive affective impacts, which appear to be the main effect of the digital tools in this study. Overall, the students are very positive to digital tools in fieldwork, preferring they were introduced early during the bachelor program, but after traditional field methods are learnt. When given a choice, most students chose to combine traditional and digital tools for their fieldwork.

• Dalslåen, Bjørgunn Heggem; Gasser, Deta; Grenne, Tor; Augland, Lars Eivind & Andresen, Arild (2020). Early - Middle Ordovician sedimentation and bimodal volcanism at the margin of Iapetus: the Trollhøtta–Kinna Basin of the central Norwegian Caledonides. Geological Society Special Publication. ISSN 0305-8719. 503, p. 251–277. doi: 10.1144/SP503-2020-37. Full text in Research Archive Show summary

  The late Neoproterozoic–Paleozoic Iapetus Ocean developed between Laurentia, Baltica, Siberia and Gondwana. Its Paleozoic closure history is recorded by volcano-sedimentary successions within the Caledonian orogen of Scandinavia, the British Isles and Newfoundland. We present new lithological, geochemical and geochronological data relevant for the Iapetan closure history from the hitherto poorly known Trollhøtta–Kinna Basin (central Norwegian Caledonides). This basin consists of alternating siliciclastic rocks, mid-ocean ridge basalts (MORBs), and felsic volcanic rocks highly enriched in, for example, Th, U and light REEs. Rhyolites from the stratigraphically upper part are dated by zircon U–Pb thermal ionization mass spectrometry to 473.3 ± 1.0 and 472.4 ± 0.7 Ma. Detrital zircon spectra indicate deposition after c. 480 Ma, with sediments derived from composite Cambro-Ordovician and Archean–Neoproterozoic landmass(es), possibly the Laurentian margin or a related microcontinent. The peculiar bimodal volcanic association is interpreted as an intermittent phase of marginal basin rifting, derived from a heterogeneous mantle source previously metasomatized by continental material. The tectonic mechanisms behind rifting could be slab retreat and/or break-off, or far-field tectonic forces within the Iapetan realm. Comparison of this basin with other Iapetus-related, similarly-aged volcano-sedimentary successions along the Caledonian–Appalachian orogen indicate that the bimodal MORBs and highly enriched rocks reflect a palaeotectonic setting hitherto unknown in the orogen.

• Svensen, Henrik; Jerram, Dougal Alexander; Polozov, Alexander; Planke, Sverre; Neal, Clive R. & Augland, Lars Eivind [Show all 7 contributors for this article] (2019). Thinking about LIPs: A brief history of ideas in Large igneous province research. Tectonophysics. ISSN 0040-1951. 760, p. 229–251. doi: 10.1016/j.tecto.2018.12.008. Full text in Research Archive Show summary

  Large igneous provinces (LIPs) are extraordinary igneous and tectonic events that have influenced the planet in profound ways, including the major turnovers in the history of life. The LIP concept, definitions, and terminology first nucleated in a 1990 workshop jointly arranged by Joint Oceanographic Institutions and U.S. Science Support Program, subsequently presented in a series of seminal papers by Millard F. Coffin and Olav Eldholm in the early 1990's. They combined existing data and information from continental flood basalts with the emerging geophysical understanding of oceanic plateaus and rifted continental margins. The new terminology had major implications within the geosciences and beyond. However, when investigating how geoscientists described and interpreted these vast provinces prior to the 1990's, we are left with a series of questions. Who first realized that LIPs represent extraordinary events in the history of the Earth, what terminology was used, and why were geologists interested in this type of events? Here we discuss some of the key developments in LIP research, including mapping projects, expeditions, international programs, correlations across continents, and the history of the terminology. We focus our discussion on four cases, the Karoo LIP, the Siberian Traps, the North Atlantic Igneous Province, and the Ontong Java Plateau, comprising key examples of LIPs with long histories of study and exploration. We conclude that the past 150 years of LIP-related research and endeavor was largely driven by a need to understand fundamental aspects of Earth evolution, including continental drift, plate tectonic reconstructions, the origin of basalt, mantle processes and plumes, and the role of volcanism in driving mass extinctions and climatic changes.

• Jochmann, Malte Michel; Augland, Lars Eivind; Lenz, Olaf; Bieg, Gerd; Haugen, Turid & Grundvåg, Sten-Andreas [Show all 10 contributors for this article] (2019). Sylfjellet: a new outcrop of the Paleogene Van Mijenfjorden Group in Svalbard. Arktos. ISSN 2364-9453. doi: 10.1007/s41063-019-00072-w. Full text in Research Archive Show summary

  A hitherto unrecognized Paleogene outcrop has been discovered at Sylfjellet, a mountain located at the northern side of Isfjorden, Svalbard. The strata, which cover an area of 0.8 km2, have until now been assigned to the Lower Cretaceous succession of the Adventdalen Group. In this study, the Sylfjellet site was studied in detail to provide an updated structural and sedimentological description of strata and lithostratigraphy. The age and burial history of the investigated succession were constrained by absolute (U/PB) and relative dating methods in addition to vitrinite reflectance analyses of coal seams. The results show a Paleogene age of the deposits, which is supported by the occurrence of an angiosperm pollen grain, plant macrofossils, and a tephra layer of early Selandian age (61.53 Ma). The 250 m-thick succession of Sylfjellet is assigned to the Firkanten, Basilika and Grumantbyen formations. This succession unconformably overlies the Lower Cretaceous Helvetiafjellet Formation. Sylfjellet is incorporated into the West Spitsbergen Fold-and-Thrust Belt and interpreted to be a fourth structural outlier of the Van Mijenfjorden Group. Vitrinite reflectance data indicate that at least 2000 m overburden has been eroded above the Sylfjellet coal seams, and that maximum burial of the strata predates folding and thrusting in the area.

• Augland, Lars Eivind; Ryabov, Viktor V.; Vernikovsky, Valery A.; Planke, Sverre; Polozov, Alexander & Callegaro, Sara [Show all 8 contributors for this article] (2019). The main pulse of the Siberian Traps expanded in size and composition. Scientific Reports. 9. doi: 10.1038/s41598-019-54023-2. Full text in Research Archive Show summary

  Emplacement of large volumes of (sub)volcanic rocks during the main pulse of the Siberian Traps occurred within <1 m.y., coinciding with the end-Permian mass extinction. Volcanics from outside the main Siberian Traps, e.g. Taimyr and West Siberia, have since long been correlated, but existing geochronological data cannot resolve at a precision better than ~5 m.y. whether (sub)volcanic activity in these areas actually occurred during the main pulse or later. We report the first high precision U-Pb zircon geochronology from two alkaline ultramafic-felsic layered intrusive complexes from Taimyr, showing synchronicity between these and the main Siberian Traps (sub)volcanic pulse, and the presence of a second Dinerian-Smithian pulse. This is the first documentation of felsic intrusive magmatism occurring during the main pulse, testifying to the Siberian Trap’s compositional diversity. Furthermore, the intrusions cut basal basalts of the Taimyr lava stratigraphy hence providing a minimum age of these basalts of 251.64 ± 0.11 Ma. Synchronicity of (sub)volcanic activity between Taimyr and the Siberian Traps imply that the total area of the Siberian Traps main pulse should include a ~300 000 km2 area north of Norilsk. The vast aerial extent of the (sub)volcanic activity during the Siberian Traps main pulse may explain the severe environmental consequences.

• Lundmark, Anders Mattias; Augland, Lars Eivind & Bjerga, Audun Dalene (2019). Timing of strain partitioning and magmatism in the Scottish Scandian collision, evidence from the high Ba–Sr Orkney granite complex. Scottish Journal of Geology. ISSN 0036-9276. 55(1), p. 21–34. doi: 10.1144/sjg2018-001. Full text in Research Archive Show summary

  The Orkney granite complex dominates the outcropping basement on Orkney, Scotland. It comprises a grey and a pink variably foliated granite, and structurally younger pegmatites and aplites. Based on geochemical characteristics the granites are assigned to the Scottish high Ba–Sr granites. The granites are deformed by synmagmatic extensional east–west-trending mylonite zones. These are locally overprinted by similarly oriented extensional phyllonites and, in one case, by similarly oriented extensional faults. The grey and the pink granites are dated by zircon U–Pb CA-ID-TIMS to 431.93 ± 0.46 and 430.26 ± 0.92 Ma, respectively. An aplite cutting mylonitic granite and cut by phyllonite is dated to 428.50 ± 0.31 Ma. We interpret the shear zones to record north–south extension during emplacement and cooling of the granites, likely at a shallow crustal depth (4–12 km). The extension is best explained by a subsidiary pull-apart structure related to displacement on the Great Glen Fault. In this case, the Orkney granite complex dates transcurrent faulting to 432–429 Ma, coeval with the 431–429 Ma Moine Thrust. This indicates that strain partitioning and high Ba–Sr magmatism across the Scottish Highlands was an immediate response to attempted subduction of Avalonia beneath Laurentia during the Scandian collision.

• Ballo, Eirik Magnus Gottschalk; Augland, Lars Eivind; Hammer, Øyvind & Svensen, Henrik (2019). A new age model for the Ordovician (Sandbian) K-bentonites in Oslo, Norway. Palaeogeography, Palaeoclimatology, Palaeoecology. ISSN 0031-0182. 520, p. 203–213. doi: 10.1016/j.palaeo.2019.01.016. Full text in Research Archive Show summary

  During the Late Ordovician, large explosive volcanic eruptions deposited worldwide K-bentonites, including the Millbrig and Deicke K-bentonites in North America and the Kinnekulle K-bentonite in Scandinavia. We have studied a classical locality in Oslo containing one of the most complete sections of K-bentonites in Europe. In a 53 m section of Sandbian age, we discovered 33 individual K-bentonite beds, the most notable beds being the Kinnekulle and the upper Grimstorp K-bentonite. Magnetic susceptibility (MS) measurements on two intervals show significant periodicity peaks interpreted as Milankovitch cycles and thus astronomically forced changes in sediment supply and composition. These cycles fit remarkably well with both the expected Milankovitch periodicities for the Ordovician as well as the radiometric ages presented in this study and may represent one of the most convincing demonstrations of Milankovitch cycles from the lower Paleozoic so far. Five of the K-bentonites have been dated by high-precision chemical abrasion-thermal ionization mass spectrometry (CA-TIMS) U-Pb zircon geochronology, where the Kinnekulle K-bentonite gives an age of 454.06 ± 0.43 Ma. We have integrated the new data and calculated an age model showing the sedimentation rates through the section and thereby the ages of each of the 33 K-bentonites. Using the age model, we further present a new age for the Sandbian-Katian stage boundary. The section in Oslo provides the highest resolution window into the Upper Ordovician K-bentonite succession so far and helps shed more light on the chronology of one of the most intense volcanic periods of the Paleozoic and the relationship with the global carbon cycle changes that followed.

• Jannin, Sophie; Gervais, Felix; Moukhsil, Abdelali & Augland, Lars Eivind (2018). Late-Grenvillian channel flow in the central Grenville Province (Manicouagan Reservoir area): New constraints from a structural and geochronological study of the Allochthon Boundary Thrust. Journal of Structural Geology. ISSN 0191-8141. 115, p. 132–151. doi: 10.1016/j.jsg.2018.07.019. Full text in Research Archive
• Svensen, Henrik; Torsvik, Trond Helge; Callegaro, Sara; Augland, Lars Eivind; Heimdal, Thea Hatlen & Jerram, Dougal Alexander [Show all 8 contributors for this article] (2018). Gondwana large igneous provinces: plate reconstructions, volcanic basins and sill volumes. In: Large Igneous Provinces from Gondwana and Adjacent Regions. Geological Society Special Publication. ISSN 0305-8719. 463, p. 17–40. doi: 10.1144/SP463.7. Full text in Research Archive
• Augland, Lars Eivind; Moukhsil, Abdelali & Solgadi, Fabien (2017). Mantle influence of syn-to late Grenvillian alkaline magmatism in the Grenville Province: causes and implications. Canadian journal of earth sciences (Print). ISSN 0008-4077. 54(3), p. 263–277. doi: 10.1139/cjes-2016-0135. Full text in Research Archive
• Jones, Morgan Thomas; Augland, Lars Eivind; Shephard, Grace; Burgess, Seth; Eliassen, Gauti Trygvason & Jochmann, Malte [Show all 10 contributors for this article] (2017). Constraining shifts in North Atlantic plate motions during the Palaeocene by U-Pb dating of Svalbard tephra layers. Scientific Reports. 7(1). doi: 10.1038/s41598-017-06170-7. Full text in Research Archive Show summary

  Radioisotopic dating of volcanic minerals is a powerful method for establishing absolute time constraints in sedimentary basins, which improves our understanding of the chronostratigraphy and evolution of basin processes. The relative plate motions of Greenland, North America, and Eurasia changed several times during the Palaeogene. However, the timing of a key part of this sequence, namely the initiation of compression between Greenland and Svalbard, is currently poorly constrained. The formation of the Central Basin in Spitsbergen is inherently linked to changes in regional plate motions, so an improved chronostratigraphy of the sedimentary sequence is warranted. Here we present U-Pb zircon dates from tephra layers close to the basal unconformity, which yield a weighted-mean 206Pb/238U age of 61.596 ± 0.028 Ma (2σ). We calculate that sustained sedimentation began at ~61.8 Ma in the eastern Central Basin based on a sediment accumulation rate of 71.6 ± 7.6 m/Myr. The timing of basin formation is broadly coeval with depositional changes at the Danian-Selandian boundary around the other margins of Greenland, including the North Sea, implying a common tectonic driving force. Furthermore, these stratigraphic tie points place age constraints on regional plate reorganization events, such as the onset of seafloor spreading in the Labrador Sea.

• Jones, Morgan Thomas; Eliassen, Gauti Trygvason; Shephard, Grace; Svensen, Henrik; Jochmann, Malte & Friis, Bjarki [Show all 9 contributors for this article] (2016). Provenance of bentonite layers in the Palaeocene strata of the Central Basin, Svalbard: implications for magmatism and rifting events around the onset of the North Atlantic Igneous Province. Journal of Volcanology and Geothermal Research. ISSN 0377-0273. 327, p. 571–584. doi: 10.1016/j.jvolgeores.2016.09.014. Full text in Research Archive
• Augland, Lars Eivind & David, Jean (2015). Protocrustal evolution of the Nuvvuagittuq Supracrustal Belt as determined by high precision zircon Lu–Hf and U–Pb isotope data. Earth and Planetary Science Letters. ISSN 0012-821X. 428, p. 162–171. doi: 10.1016/j.epsl.2015.07.039. Full text in Research Archive Show summary

  The Nuvvuagittuq Supracrustal Belt (NSB) in northern Quebec, Canada, represents one of the oldest known crustal fragments preserved in the Earth's crust. Its age has, however, been disputed and different authors present crustal formation ages varying from ca. 3.8 Ga to 4.4 Ga (e.g. O'Neil et al., 2012 and Guitreau et al., 2013). Here we report new high precision U–Pb geochronological and coupled Lu–Hf isotope data from zircons that reveal the age of the NSB and provide new constraints on the source rocks to this piece of early crust. Two rocks have been analysed, a felsic schist, interpreted to represent a volcanite, and a mylonitic tonalite that is intrusive into the NSB. The felsic schist was emplaced at 3771+5/−3 Ma, dating the formation of the NSB. The Lu–Hf model age indicates that the parental melt to the felsic schist was extracted from the mantle at this age or within a few tens of million years, but no more than 300 m.y., before its extrusion. This mantle extraction age provides an absolute maximum age for the NSB, but the most probable age of its protocrust is ca. 3.8 Ga. The mylonitic tonalite was emplaced at 3667+3/−1 Ma. Its Lu–Hf isotopic composition reveals the presence of an older crustal component than that of the NSB, requiring that its precursor melt formed from a Hadean source that was older than the NSB. Based on recent models for Archean TTG formation, we propose that this source represents re-melted Hadean hydrated crust that must have been translated below the NSB at ca. 3667 Ma.

• Augland, Lars Eivind; Moukhsil, Abdlali; Solgadi, Fabien & Indares, Aphrodite (2015). Pinwarian to Grenvillian magmatic evolution in the central Grenville Province-new constraints from ID-TIMS U-Pb ages and coupled Lu-Hf S-MC-ICP-MS data. Canadian journal of earth sciences (Print). ISSN 0008-4077. 52(9), p. 701–721. doi: 10.1139/cjes-2014-0232. Full text in Research Archive Show summary

  Understanding the magmatic evolution of the rocks once comprising the hinterland of the Grenville Orogen through their Mesoproterozoic formation is a key to understanding the Grenvillian Orogeny as a whole. In this contribution, we present high-precision isotope dilution thermal ionization mass spectrometry (ID–TIMS) U–Pb and coupled solution multicollector inductively coupled plasma mass spectrometry (S–MC–ICP–MS) Lu–Hf zircon data from magmatic rocks occurring in the allochthonous belt of the Grenville Orogen in the central part of the Grenville Province. We document the presence of a large tract of Pinwarian crust represented by a 1497 ± 5 Ma granitic gneiss, as well as large late Geon 14 to early Geon 13 (1434 +7/−11, 1413 ± 12, 1393 ± 8, 1383 ± 1 Ma) magmatic complexes. One Grenvillian plutonic suite of 1015 ± 2 Ma that cross-cuts the host-rock metamorphic fabric has also been dated. This age provides a minimum age of Ottawan metamorphism in the region. The Hf-isotopic data show that the magmatic rocks of Geons 14 and 13 had mixed mantle and crustal sources compatible with intrusion in a supra-subduction setting as is also supported by the whole-rock geochemical data presented. Emplacement of the magmatic rocks occurred in settings varying from a distal margin arc to a contractional and extensional continental arc. Grenvillian-aged magmatism is more ambiguous, but our data indicate that rocks as young as ca. 1015 Ma may have formed in an ensialic setting.

• Augland, Lars Eivind; Andresen, Arild; Corfu, Fernando; Agyei-Dwarko, Nana Yaw & Larionov, Alexander (2014). The Bratten-Landegode gneiss complex - a fragment of Laurentian continental crust in the Uppermost Allochthon of the Scandinavian Caledonides. Geological Society Special Publication. ISSN 0305-8719. 390(1), p. 633–654. doi: 10.1144/SP390.1. Full text in Research Archive
• Augland, Lars Eivind; Andresen, Arild; Gasser, Deta & Steltenpohl, Mark G. (2014). Early Ordovician to Silurian evolution of exotic terranes in the scandinavian caledonides of the Ofoten-Troms area-terrane characterization and correlation based on new U-Pb zircon ages and Lu-Hf isotopic data. Geological Society Special Publication. ISSN 0305-8719. 390(1), p. 655–678. doi: 10.1144/SP390.19. Full text in Research Archive
• Augland, Lars Eivind; Andresen, Arild; Corfu, Fernando & Daviknes, Hans Kristian (2012). Late Ordovician to Silurian ensialic magmatism in Liverpool Land, East Greenland: new evidence extending the northeastern branch of the continental Laurentian magmatic arc. Geological Magazine. ISSN 0016-7568. 149(4), p. 561–577. doi: 10.1017/S0016756811000781. Full text in Research Archive
• Lundmark, Anders Mattias; Andresen, Arild; Hasan, M.A.; Augland, Lars Eivind & Boghdady, G.Y. (2012). Repeated magmatic pulses in the East African Orogen in the Eastern Desert, Egypt: An old idea supported by new evidence. Gondwana Research. ISSN 1342-937X. 22(1), p. 227–237. doi: 10.1016/j.gr.2011.08.017. Full text in Research Archive

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• Ryen, Sofie Hildegard; Domeier, Mathew Michael; Augland, Lars Eivind & Boon, Annique van der (2026). Investigating anomalous behaviour of Earth’s magnetic field in the mid- Palaeozoic – preliminary palaeomagnetic results from Silurian Ringerike sandstone of the Oslo Region, Norway. Full text in Research Archive
• Andersen, Gard Lilledal; Svensen, Henrik Hovland; Deegan, Frances M.; Callegaro, Sara; Whattam, Jack William & Jeon, Heejin [Show all 8 contributors for this article] (2026). Small crystals, big eruptions: Quartz phenocrysts as archives of caldera-forming processes in the Permian Drammen Caldera, Oslo Rift, Norway. Full text in Research Archive Show summary

  Caldera-forming eruptions are among the most dangerous and catastrophic volcanic phenomena, yet the related magma reservoir processes are poorly understood. In the Permo-Carboniferous Oslo Rift in Southeastern Norway, there are at least 15 calderas, several of which have preserved pyroclastic deposits. Here we focus on a >450 m thick rhyolitic ignimbrite succession in the 7 x 7 km Drammen Caldera, located 40 km southwest of Oslo. We present field observations, petrography, and geochemical analyses, with an emphasis on primary quartz phenocrysts. Ignimbrite stratigraphy in the Drammen Caldera comprises the high-grade, phenocryst-rich Lian Formation (25–30% crystals) and the moderate- to low-grade, phenocryst-poor Sørumlia Formation (1–2% crystals). The Lian Formation records a large, sustained pyroclastic eruption that tapped a crystal-rich part of the reservoir, whereas the Sørumlia Formation was deposited over several smaller, highly explosive eruptions sourced from crystal-poor magma batches. In both formations, primary quartz phenocrysts occur as euhedral, rounded, and embayed crystals, and range in size from 50 to 2000 μm. Cathodoluminescence (CL) imaging of primary quartz phenocrysts reveals widespread oscillatory zoning, and several crystals show a distinct core with resorption margin, indicating changing magma reservoir conditions during crystal growth. To investigate the origin of the zoning, we conducted in situ oxygen and silicon isotope analyses. The primary quartz has an average δ18O value of 8.03 ± 0.23‰, suggesting assimilation of high-δ18O Lower Palaeozoic sedimentary rocks surrounding the caldera. As most intracrystal values are indistinguishable within the analytical uncertainty, we interpret assimilation to have occurred prior to quartz growth. Quartz phenocrysts yield an average δ30Si value of -0.08 ± 0.43‰. Like oxygen, silicon isotopes show no significant inter- or intracrystal variation, indicating isotopic homogeneity of the melt prior to the ignimbrite-forming eruptions. The combination of textural complexity and isotopic homogeneity in primary quartz phenocrysts provides new insights into felsic magma reservoir processes in the Oslo Rift.

• Gasser, Deta; Grenne, Tor; Bøe, Reidulv; Corfu, Fernando; Augland, Lars Eivind & Nordgulen, Øystein [Show all 9 contributors for this article] (2025). A review of Ordovician continental arc magmatism from the Utsira High to Helgeland. Full text in Research Archive
• Gasser, Deta; Grenne, Tor; Bøe, Reidulv; Corfu, Fernando; Augland, Lars Eivind & Nordgulen, Øystein [Show all 9 contributors for this article] (2025). Mid-late Ordovician continental arc development in the central Scandinavian Caledonides. Full text in Research Archive
• Andersen, Gard Lilledal; Svensen, Henrik Hovland; Augland, Lars Eivind; Callegaro, Sara; Whattam, Jack William & Deegan, Frances M. [Show all 8 contributors for this article] (2025). Unravelling the eruption history of the Drammen Caldera: A multidisciplinary study of caldera-forming processes in the Permian Oslo Rift, Norway. Full text in Research Archive Show summary

  During the mature stages of the Permo-Carboniferous Oslo Rift, at least 15 calderas formed. Thick ignimbrite deposits are preserved in several of these calderas but remain poorly studied with modern methods. This study focuses on a rhyolitic ignimbrite succession in the 7x7 km Drammen Caldera, located 40 km southwest of Oslo. Here, we present field observations, petrographic results, and geochemical analyses of the deposits. Despite significant glacial erosion and partial Quaternary coverage, we show that over 450 m of ignimbrite stratigraphy is preserved in the Drammen Caldera. In addition, we have identified ashfall and lahar deposits interbedded between ignimbrite units. The ignimbrites range from high- to low-welding grade, and we interpret them to record at least five explosive eruptions resulting in two caldera collapse events. The ignimbrites are altered but retain primary volcanic textures. Cathodoluminescence (CL) reveals complex zoning patterns in quartz phenocrysts, indicating multiple growth and dissolution stages. Phenocrysts are heavily fragmented, with fractures healed by quartz cementation. Oxygen isotopes measured in-situ in zoned quartz phenocrysts suggest assimilation of high-δ18O Lower Palaeozoic sedimentary rocks surrounding the caldera. Ongoing work on silicon isotopes and U-Pb geochronology aims to further refine the timing and petrogenetic processes. We conclude that the ignimbrites preserved in the Drammen Caldera hold information about complex magma reservoir dynamics, leading to several explosive eruptions. We present a six-stage evolution model for the caldera. This study highlights the potential for detailed multidisciplinary ignimbrite studies in other Oslo Rift calderas, as well as other eroded calderas globally.

• Michalski, Krzysztof; Majka, Jarosław; Głowacki, Piotr; Augland, Lars Eivind; Manby, Geoffrey Martin & Piepjohn, Karsten [Show all 8 contributors for this article] (2025). SVALGEOBASE II: Tectono-thermal Evolution of Svalbard – from Metamorphic and Magmatic Processes to Geothermal Energy. Geological Workshop, Svalbard, 3–9 September 2024. doi: 10.25171/InstGeoph_PAS_Publs-2025-001. Full text in Research Archive Show summary

  We are pleased to present the report from the second edition of the geological workshop SvalGeoBase II, titled “Tectono-thermal evolution of Svalbard – from metamorphic and mag-matic processes to geothermal energy”. Held from September 3 to 9, 2024, in Svalbard, this event continued the legacy of the first edition, SvalGeoBase I, organized in 2013 under the theme “Proterozoic and Lower Palaeozoic basement of Svalbard – state of knowledge and new research perspectives”. Once again, this ambitious project aimed to host an Arctic scientific conference aboard an expedition vessel. Through multiple landings in the northern Spitsbergen region and Nor-daustlandet, participants had the rare opportunity to engage in field discussions and closely examine rock outcrops that are at the forefront of ongoing scientific debates within the Arctic geology community. The Svalbard Archipelago once again provided the backdrop for the activities of SvalGeo-Base II. Svalbard’s exceptional geological profile spans rocks ranging from the Early Protero-zoic to the Neogene, offering a detailed record of this Arctic region’s paleogeographic and tectono-thermal evolution. It reflects key processes such as the formation and breakup of the Proterozoic supercontinent Rodinia, the opening of the Iapetus Ocean, the Caledonian collision, and the more recent history tied to the expansion of young oceanic basins in the North Atlantic and the Eurasian Basin.

• Lundmark, Anders Mattias; Bakken, Kristian Bjelbøle; Anell, Ingrid; Augland, Lars Eivind; Conrad, Clinton Phillips & Dunkel, Kristina G [Show all 10 contributors for this article] (2025). Why don’t my students come to class? Full text in Research Archive
• Lundmark, Anders Mattias; Bakken, Kristian Bjelbøle; Anell, Ingrid; Augland, Lars Eivind; Conrad, Clinton Phillips & Dunkel, Kristina G [Show all 10 contributors for this article] (2025). “Why don’t my students come to class?”. Full text in Research Archive
• Lundmark, Anders Mattias; Bakken, Kristian Bjelbøle; Anell, Ingrid; Augland, Lars Eivind; Conrad, Clinton Phillips & Dunkel, Kristina G [Show all 10 contributors for this article] (2025). “Why don’t my students come to class?”. Full text in Research Archive
• Nygaard, Madeleine Skov; Planke, Sverre; Berndt, Christian; Zastrozhnov, Dmitry; Faleide, Jan Inge & Jones, Morgan Thomas [Show all 18 contributors for this article] (2025). Mimir High Core-log-seismic Integration. Full text in Research Archive
• Andersen, Guro Lilledal; Svensen, Henrik Hovland; Augland, Lars Eivind; Callegaro, Sara & Whattam, Jack (2024). The explosive volcanism of the Oslo Rift – insights from the ignimbrites of the Drammen Caldera. Full text in Research Archive
• Callegaro, Sara; Svensen, Henrik Hovland; Heimdal, Thea H.; Kjøll, Hans Jørgen; Harstad, Andreas Olaus & Augland, Lars Eivind [Show all 9 contributors for this article] (2024). Geochemistry of sills from the early stage of the Oslo Rift. Full text in Research Archive
• Jones, Morgan; Rooney, Alan; Zuchuat, Valentin; Turner, Holly; Frieling, Joost & Mather, Tamsin [Show all 14 contributors for this article] (2024). Volcanic proxies from the northern Pangean margin across the Permian-Triassic boundary: Evidence of intermittent Siberian Traps activity. Full text in Research Archive
• Augland, Lars Eivind; Midtkandal, Ivar; Svensen, Henrik Hovland & Planke, Sverre (2024). Detrital zircons in reworked tephra deposits – a proxy for contourites? Full text in Research Archive
• Nygaard, Madeleine Skov; Planke, Sverre; Berndt, Christian; Zastrozhnov, Dmitry; Faleide, Jan Inge & Jones, Morgan Thomas [Show all 24 contributors for this article] (2024). PALMAR – Paleogene Basin Development on the Vøring and Møre Margins. Full text in Research Archive
• Nygaard, Madeleine Skov; Planke, Sverre; Berndt, Christian; Zastrozhnov, Dmitry; Faleide, Jan Inge & Jones, Morgan Thomas [Show all 24 contributors for this article] (2024). IODP Exp. 396 Drilling and High-Resolution 3D Seismic on the Mimir High. Full text in Research Archive
• Augland, Lars Eivind; Lundmark, Anders Mattias; Callegaro, Sara & Jerram, Dougal Alexander (2023). Rapid translithospheric ascent rates for Lamprophyres from zircon dissolution speedometry. Full text in Research Archive
• Gasser, Deta; Meyer, Gurli Birgitte; Ksienzyk, Anna Katharina; Ofstad, Frode; Augland, Lars Eivind & Slagstad, Trond [Show all 7 contributors for this article] (2023). The Grønfjellet unit – an alkaline volcanic complex of uncertain tectonic affiliation in the eastern Trondheim Nappe Complex. Full text in Research Archive
• Ryen, Sofie Hildegard; Lundmark, Anders Mattias & Augland, Lars Eivind (2023). The imbricate fans of Huk, Oslo. Full text in Research Archive
• Svebo, Joachim Røed; Lundmark, Anders Mattias & Augland, Lars Eivind (2022). Deciphering the setting of volcaniclastic and effusive Devonian magmatism in the Orcadian basin, Orkney Islands, Scotland. Full text in Research Archive
• Augland, Lars Eivind; Lundmark, Anders Mattias; Rian, Maiken Thorvaldsen & Jerram, Dougal Alexander (2022). Non-dissolved mantle zircons record hyper rapid translithospheric ascent of lamprophyres. Full text in Research Archive
• Ryen, Sofie Hildegard; Lundmark, Anders Mattias & Augland, Lars Eivind (2022). How Caledonian structures camouflage as Permo-Carboniferous structures in the Oslo Region, Norway. Full text in Research Archive
• Zuchuat, Valentin; Augland, Lars Eivind; Jones, Morgan Thomas; Sleveland, Arve R.N.; Twitchett, Richard & Tovar, Francisco J Rodríguez [Show all 13 contributors for this article] (2022). The Permian-Triassic boundary across the Barents Shelf: an intricate record of climate change, mass extinction, recovery, and basin reorganisation. EGU General Assembly. doi: 10.5194/egusphere-egu22-2379. Full text in Research Archive
• Ryen, Sofie Hildegard; Lundmark, Anders Mattias & Augland, Lars Eivind (2021). Strike-slip faults in the Oslo Region – Caledonian compression or Permian transtension. Full text in Research Archive
• Zuchuat, Valentin; Augland, Lars Eivind; Jones, Morgan Thomas; Twitchett, Richard; Rodríguez-Tovar, Francisco J. & Hammer, Øyvind [Show all 11 contributors for this article] (2021). Facies changes, volcanism, and mass extinction conundrum: the Permian-Triassic boundary across the Barents Sea Shelf. Full text in Research Archive Show summary

  The most dramatic mass extinction the Earth has ever experienced occurred 252 million years ago, at the end of the Permian. It was likely triggered by the volcanic eruptions and magmatic intrusions associated with the Siberian Traps Large Igneous Province (LIP), leading to dramatic climatic changes, with consequences lasting well into the Early Triassic. Here, we present a summary of the findings from the study of several sedimentary successions distributed across the Barents Sea that spanned the End Permian Mass Extinction (EPME) and the Permian-Triassic boundary. The four studied successions included the renowned Festningen section in the outer part of Isfjorden, western Spitsbergen; the DD-1 core and the associated river section in Deltadalen, central Spitsbergen; a core drilled offshore Kvitøya in northern Svalbard, and a core drilled on the Horda Platform in the Barents Sea. Datasets of various research lines were collected from these sections including sedimentology, organic geochemistry, isotope, geochronology, XRF, mineralogy, ichnology, palaeontology, palynology and digital outcrop data. Historically, the Permian-Triassic boundary exposed today in Svalbard (and at various places across the High Arctic regions) was placed at the very prominent and abrupt facies change occurring between the siliceous mudstones or spiculites of the Kapp Starostin Formation, and the overlying soft, non-siliceous mudstones and siltstones of the Vardebukta and Vikinghøgda formations. The abruptness of this facies change, which also marks the demise of sponges, led to the belief that it represented a hiatus or a gap of several million years, with the uppermost Permian strata missing from the sedimentary record, while the mudstones of the Vardebukta and Vikinghøgda formations were definitely of Lower Triassic age, based on ammonoid biostratigraphy. Hindeodus parvus, the conodont that defines the base of the Triassic, was for the first time identified in Svalbard a few meters above the lithostratigraphic boundary, which is therefore of Upper Permian age. Additionally, our new data show that sedimentation was continuous across this lithostratigraphic boundary. This transition from the Kapp Starostin Formation to the Vardebukta and Vikinghøgda formations was accompanied by a major reorganisation/inversion of the basin(s), but its exact nature remains puzzling. Further, all measured sections record the EPME, which is associated with a 6-8 ‰ δ13CVPDB negative excursion, and measured between the lithostratigraphic and the Permian-Triassic boundaries. These negative isotopic excursions are found in close vicinity to several tephra layers that have been precisely dated at 252.13 ± 0.62 Ma, strongly suggesting a connection to the Siberian Traps LIP event. The mass extinction is also confirmed by the very rapid decreasing of trace fossil abundance and diversity, as anoxia spread across the water from proximal and shallow water to deeper settings. Geochemical and ichnological data indicate the occurrence of several anoxic pulses, intersected by very brief episodes of improved oxygenation levels. It took ca. 145 Kyr for life to recover after the extinction event, based on sedimentation rate calculations. Data also suggest that a shift towards more arid climatic conditions and increased eutrophication on land accompanied the EPME.

• Jones, Morgan Thomas; Stokke, Ella Wulfsberg; Augland, Lars Eivind; Svensen, Henrik; Strandmann, Philip A.E. Pogge von & Rooney, Alan (2020). Constraining the activity of the North Atlantic Igneous Province across the Paleocene-Eocene boundary. Full text in Research Archive
• Jones, Morgan Thomas; Stokke, Ella Wulfsberg; Augland, Lars Eivind; Strandmann, Philip A.E. Pogge von; Liu, Emma J. & Mather, Tamsin [Show all 13 contributors for this article] (2020). Constraining North Atlantic Igneous Province (NAIP) activity during the late Paleocene and early Eocene. Full text in Research Archive
• Ryen, Sofie Hildegard; Lundmark, Anders Mattias & Augland, Lars Eivind (2020). Investigating Tear Faults in the Oslo Region. Full text in Research Archive
• Dalslåen, Bjørgunn Heggem; Gasser, Deta; Grenne, Tor; Andresen, Arild; Augland, Lars Eivind & Corfu, Fernando (2020). Tectonic evolution of Ordovician-Silurian rocks in the Oppdal area, southern Trondheim Nappe Complex. Full text in Research Archive
• Jochmann, Malte Michel; Augland, Lars Eivind; Lenz, Olaf; Bieg, Gerd; Haugen, Turid & Grundvåg, Sten-Andreas [Show all 10 contributors for this article] (2019). Revised stratigraphy of Sylfjellet, Svalbard: a new contribution to the Paleogene Van Mijenfjorden Group. Full text in Research Archive Show summary

  The strata of Sylfjellet, a mountain located on the northern side of Isfjorden, central Spitsbergen, have so far been solely assigned to the Lower Cretaceous (Harland et al., 1997; Braathen et al., 1999; Bergh et al., 2003,). The strata are incorporated in the Eurekan West Spitsbergen Fold and Thrust Belt (WSFTB) (Braathen et al., 1999; Dallmann, 2015, Piepjohn et al., 2016). Recent stratigraphic studies of the succession of presumable Early Cretaceous age suggested the presence of Paleogene strata. Thus, we revisited the site in order to find evidence for a Paleogene age of the strata. The outcomes of this study are presented here. The area was mapped and the c. 250 m thick succession was logged. Samples were collected for both absolute (U/PB) and relative (palynological) dating methods. In addition, coal seams were analysed for vitrinite reflectance, allowing us to analyse the strata in a broader geological context. Our findings show that parts of the investigated strata at Sylfjellet are of Paleogene age. The mapped succession was assigned to the Van Mijenfjorden Group and comprises the Firkanten, Basilika and Grumantbyen formations. They directly overlie Lower Cretaceous strata with a sedimentary contact. Since the strata are situated within the WSFTB, they represent a third tectonic outlier of the Van Mijenfjorden Group in Svalbard, in addition to the previously described Ny-Ålesund Subgroup and the Øyrlandet Graben deposits in southern Spitsbergen (Harland et al., 1997; Dallmann et al., 1999;). Our stratigraphic revision of the Sylfjellet succession has several implications for the interpretation of the Paleogene depositional history and the interplay between Eocene sedimentation and tectonics. Vitrinite reflection data indicates that an Upper Eocene or Oligocene age for the Aspelintoppen Formation is precluded, or that alternatively an Upper Eocene/Oligocene folding and thrusting event must have taken place in this area. Bergh, S., Ohta, Y., Andresen, A., Maher, H., Braathen, A. & Dallmann, W. (2003). Geological Map of Svalbard, 1: 100 000 Sheet B8G St. Jonsfjorden. Norsk Polarinstitutt Temakart (34). Braathen, A., Bergh, S., Karlsen, F., Maher, H., Andresen, A., Hansen, A.-I. & Bergvik, A. (1999). Kinematics of the Isfjorden-Ymerbukta Fault Zone: a dextral oblique-thrust ramp in the Tertiary fold-thrust belt of Spitsbergen. Norsk Geologisk Tidsskrift 79, 227–240. Dallmann, W. K. (editor), International Stratigraphic Committee for Svalbard (1999). Lithostratigraphic lexicon of Svalbard. Review and recommendations for nomenclature use. Upper Palaeozoic to Quaternary bedrock. Norwegian Polar Institute, Norway, 318 pages. Dallmann, W. K. (editor) (2015). Geoscience Atlas of Svalbad. Norwegian Polar Institute Report Series No 148, Norwegian Polar Institute, Norway, 292 pages. Harland, W. B., Anderson, L. M., Manasrah, D. & Butterfield, N. J. (1997). The Geology of Svalbard. Geological Society, London, Memoir No. 17, 521 pages. Piepjohn, K., von Gosen, W. & Tessensohn, F. (2016). The Eurekan deformation in the Arctic: an outline. Journal of the Geological Society, 173, 1007–1024.

• Svebo, Joachim Røed; Lundmark, Anders Mattias & Augland, Lars Eivind (2019). High precision dating of the Devonian Hoy volcanics, Orkney, northern North Sea, and its implications. Full text in Research Archive
• Gasser, Deta; Grenne, Tor; Augland, Lars Eivind & Corfu, Fernando (2019). The Støren Group of the Trondheim Nappe Complex revisited: rift-related early/middle Ordovician volcanism and turbidite sedimentation at the onset of westward subduction? Full text in Research Archive
• Dalslåen, Bjørgunn Heggem; Gasser, Deta; Grenne, Tor; Augland, Lars Eivind & Corfu, Fernando (2019). The origin of Th-enriched volcanic rocks in Oppdal, central Norwegian Caledonides – implications for the evolution of Ordovician arc magmatism. Full text in Research Archive
• Jones, Morgan Thomas; Stokke, Ella Wulfsberg; Strandmann, Philip A.E. Pogge von; Augland, Lars Eivind; Svensen, Henrik & Whiteside, Jessica H. [Show all 7 contributors for this article] (2019). ASHLANTIC: A multi-proxy approach to understanding the relationship between the NAIP and the PETM. Full text in Research Archive
• Grenne, Tor; Gasser, Deta; Corfu, Fernando; Augland, Lars Eivind; Bøe, Reidulv & Slagstad, Trond (2019). The Hølonda and Ilfjellet volcano-sedimentary basins of the central Norwegian Caledonides: Early/Middle Ordovician response to ophiolite obduction, subduction initiation and continental-arc establishment. Full text in Research Archive
• Gasser, Deta; Grenne, Tor; Dalslåen, Bjørgunn Heggem; Corfu, Fernando; Augland, Lars Eivind & Bøe, Reidulv [Show all 7 contributors for this article] (2019). Contemporaneous MORB-type and extremely enriched volcanic rocks in the central Scandinavian Caledonides: the effect of slab break-off after arc-continent collision and/or subduction initiation after polarity flip? Full text in Research Archive
• Jones, Morgan Thomas; Stokke, Ella Wulfsberg; Stradmann, Philip Pogge von; Augland, Lars Eivind; Svensen, Henrik & Whiteside, Jessica H. [Show all 7 contributors for this article] (2019). Ashlantic: A multi-proxy approach to understanding the relationship between the North Atlantic Igneous Province and the Paleocene-Eocene Thermal Maximum. Full text in Research Archive
• Lundmark, Anders Mattias; Augland, Lars Eivind & Jørgensen, Simen Varkøy (2018). How do digital tools influence geoscience students learning experience in the field? Full text in Research Archive
• Dalslåen, Bjørgunn Heggem; Gasser, Deta; Grenne, Tor; Augland, Lars Eivind; Corfu, Fernando & Andresen, Arild (2018). Chemistry, age and tectonic evolution of the western Trondheim Nappe Complex in the Oppdal area, Central Norway. Full text in Research Archive
• Svensen, Henrik; Jerram, Dougal Alexander; Polozov, Alexander; Jones, Morgan Thomas; Augland, Lars Eivind & Planke, Sverre (2018). Volcanic causes for the PETM and other past hothouse climates. Full text in Research Archive
• Jones, Morgan Thomas; Stokke, Ella Wulfsberg; Schultz, Bo; Augland, Lars Eivind; Planke, Sverre & Tegner, Christian [Show all 9 contributors for this article] (2018). Fur Island in Denmark: A window into Paleocene-Eocene hyperthermals and North Atlantic volcanism. Full text in Research Archive
• Jerram, Dougal Alexander; Svensen, Henrik; Planke, Sverre; Millett, John M; Jones, Morgan Thomas & Augland, Lars Eivind [Show all 7 contributors for this article] (2018). Types and styles of volcanism in the North Atlantic Igneous Province: Implications towards understanding their potential climatic impact. Full text in Research Archive
• Lundmark, Anders Mattias; Augland, Lars Eivind & Bjerga, Audun Dalane (2018). Syn-collisional Scandian extension and magmatism on the Orkney Islands, Scotland. Full text in Research Archive
• Augland, Lars Eivind; Lundmark, Anders Mattias & Bjerga, Audun Dalane (2018). Early mid-Devonian volcanism dates initiation of the Orcadian basin in the Orkney Islands, Scotland. Full text in Research Archive
• Gasser, Deta; Grenne, Tor & Augland, Lars Eivind (2017). The enigmatic Gula Complex of the central Norwegian Caledonides: new constraints on age and origin from zircon dating and geochemistry. Full text in Research Archive
• Jones, Morgan Thomas; Augland, Lars Eivind; Shephard, Grace; Burgess, Seth; Eliassen, Gauti & Jerram, Dougal Alexander [Show all 10 contributors for this article] (2017). Bentonite layers in Svalbard: constraining sources of volcanism, geochronology, and relative plate motions during the Paleogene. Full text in Research Archive
• Gasser, Deta; Grenne, Tor; Corfu, Fernando & Augland, Lars Eivind (2016). Characterization of depositional age and structure of sedimentary successions by U-Pb TIMS and LA-ICP-MS dating of volcanic horizons and detrital zircons: an example from the western Trondheim Nappe Complex, Scandinavian Caledonides. Full text in Research Archive
• Jones, Morgan Thomas; Augland, Lars Eivind; Tegner, Christian; Planke, Sverre; Jerram, Dougal Alexander & Callegaro, Sara [Show all 8 contributors for this article] (2016). Volcano-climate interactions during the Paleocene-Eocene Thermal Maximum: Assessing the impact of the North Atlantic Igneous Province from the Fur Formation, Denmark. Full text in Research Archive
• Jones, Morgan Thomas; Augland, Lars Eivind; Svensen, Henrik; Tegner, Christian; Planke, Sverre & Willumsen, Pi Suhr (2016). Volcano-climate interactions during the PETM and U-Pb dating from the Fur Formation, Denmark. Full text in Research Archive
• Jones, Morgan Thomas; Augland, Lars Eivind; Burgess, Seth; Eliassen, Gauti; Svensen, Henrik & Jerram, Dougal Alexander [Show all 9 contributors for this article] (2016). Bentonite layers in Svalbard: constraining sources of volcanism, geochronology, and relative plate motions during the Paleocene and Eocene. Full text in Research Archive
• Augland, Lars Eivind; Jones, Morgan Thomas; Svensen, Henrik & Tegner, Christian (2016). Closing in on the Palaeocene-Eocene Thermal Maximum in the North Atlantic: chronostratigraphy and ash bed provenance through high precision U-Pb and Lu-Hf isotopic analyses of zircons. Full text in Research Archive
• Augland, Lars Eivind; Jones, Morgan Thomas; Planke, Sverre; Svensen, Henrik & Tegner, Christian (2016). Evaluating the provenance of Permian-Triassic and Palaeocene-Eocene ash beds by high precision U-Pb and Lu-Hf isotopic analyses of zircons: linking local sedimentary records to global events. Full text in Research Archive
• Augland, Lars Eivind; Jones, Morgan Thomas; Svensen, Henrik & Planke, Sverre (2016). Improving the geochronology of the North Atlantic Igneous Province. largeigneousprovinces.org. Full text in Research Archive
• Planke, Sverre; Zuchuat, Valentin; Svensen, Henrik; Hammer, Øyvind; Braathen, Alvar & Silkoset, Petter [Show all 27 contributors for this article] (2016). Coring and High-Resolution Imaging of the Permian-Triassic Boundary in Deltadalen, Svalbard. Full text in Research Archive
• Planke, Sverre; Twitchett, Richard; Zuchuat, Valentin; Svensen, Henrik; Hammer, Øyvind & Braathen, Alvar [Show all 22 contributors for this article] (2015). Coring the Permian-Triassic Boundary in Deltadalen, Svalbard. Full text in Research Archive
• Jones, Morgan Thomas; Eliassen, Gauti Trygvason; Burgess, Seth; Augland, Lars Eivind; Svensen, Henrik & Planke, Sverre [Show all 8 contributors for this article] (2015). Palaeocene-Eocene volcanism in the Arctic: Basin development and continental breakup constrained by ash layers in Svalbard. Full text in Research Archive
• Steltenpohl, Mark G.; Andresen, Arild; Augland, Lars Eivind & Agyei-Dwarko, Nana Yaw (2014). Implications of Laurentian Grenville crust in the northern Scandinavian Caledonides. Full text in Research Archive
• Steltenpoh, M.; Andresen, Arild; Augland, Lars Eivind; Prouty, J. & Corfu, Fernando (2014). Implications of Laurentian Grenville crust in the northern Scandinavian Caledonides. Full text in Research Archive
• Andresen, Arild; Agyei-Dwarko, Nana Yaw; Steltenpohl, Mark G. & Augland, Lars Eivind (2014). Terranes within the Arctic Caledonides and their constraints on Early Paleozoic orogenic evolution. Full text in Research Archive
• Augland, Lars Eivind; Andresen, Arild & Steltenpohl, Mark G. (2013). U-Pb ID-TIMS zircon ages and coupled Lu-Hf S-ICP-MS data - A tool for terrane characterisation and determination of paleogeopgraphic affinities: An example from the Caledonides. Full text in Research Archive
• Augland, Lars Eivind; Prouty, Jonathan; Corfu, Fernando; Andresen, Arild; Agyei-Dwarko, Nana Yaw & Steltenpohl, Mark G. (2012). Intercontinental interactions: Laurentian crustal pieces in the northern Scandinavian Caledonides. Full text in Research Archive
• Augland, Lars Eivind; Andresen, Arild; Corfu, Fernando; Simonsen, Siri Lene & Andersen, Tom (2012). The Beiarn Nappe Complex: a record of Laurentian Early Silurian arc magmatism in the Uppermost Allochthonon, Scandinavian Caledonides. Full text in Research Archive
• Andresen, Arild; Augland, Lars Eivind; Moecher, David; Richarde, Gabriel; Bruechner, Hannes & Ravna, Erling J Krogh (2012). P-T-t constraints on subduction and exhumation of the Liverpool Land Eclogite Terrane (LLET), East Greenland Caldonides. Full text in Research Archive
• Syversen, Lill Karoline; Augland, Lars Eivind; Galland, Olivier; Svensen, Henrik Hovland & Callegaro, Sara (2025). Using xenoliths as tracers of magmatic processes in the Oslo Rift. Universitetet i Oslo. Full text in Research Archive Show summary

  As magma travels through the Earth’s crust, it interacts with the host rock. During ascent, magma can entrain host rock xenoliths which may be preserved in the intrusions, providing important information of the magma ascent and subsurface constituents. In the Permian Oslo Rift, several dikes and sills contain xenoliths. This study aims to obtain a greater understanding of the magma ascent- and emplacement history during the Oslo Rift volcanism by studying these xenoliths. With a multidisciplinary approach using geochemistry, petrography, and photogrammetry, this study explores the mechanisms of xenolith-formation, and further how the dikes and sills are connected to the large-scale plumbing system of the Oslo Rift. Five localities across ~95 km in the Oslo Rift reveals several xenolith lithologies derived from different crustal depths: Lithologies from Lindøya and Bevøya comprises of gneisses, metamorphic quartz, and sandstones. Near Buhammeren, xenoliths of amphibole-gabbro and bytownite-anorthosite are observed. The variety in lithologies suggests a range of entrainment depths from gabbroic sources in the lower deep crust, the Precambrian basement, and Cambro-Devonian sediments. The angularity of xenoliths is averagely estimated as “rounded”, and the estimated 3D-shapes often occurs as near equant-shaped. An increase in roundness, possibly coupled with increasingly equant shapes, are interpreted as being indicative of a longer residence time in the magma. Near Buhammeren and in Jevnaker, amphibole- and pyroxene phenocrysts- and xenoliths reveal crystallization depths of 20–30 ± 3.02 km and 22–35 ± 5.1 km respectively, interpreted as corresponding to deep crustal magma chambers. This supports former studies on the large-scale Oslo Rift plumbing system, where the lower 30 – 20 km of the crust is interpreted as a gabbroic cumulate intrusive layer formed by a prolonged period of magma fractionation. The samples bulk-rock compositions also reveal significant similarities – both compared to the early B1-basalt and compared to one another. This is indicative of a similar magma source that ascended through the crust before significant magma fractional crystallization occurred. This thesis shows the importance of studying xenoliths in the Oslo Rift, as these can provide important information on both crustal compositions and magmatic processes. Further studies should focus on constraining better depth estimates for phenocryst crystallization, as well as acquiring more accurate xenolith entrainment depths for a better understanding of the magma ascent history.

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