Fiord Formation Research Articles

Alkaline picritic volcanism on northern Ellesmere Island associated with initial rifting of the Sverdrup Basin, Canadian Arctic

The Caledonian and Ellesmerian orogenies were followed by extension and development of intracontinental rift basins since the late Paleozoic, as represented by the Sverdrup Basin along the Canadian Arctic Islands. The initial rifting was accompanied by pulses of volcanic activity during the Carboniferous and Permian. A new occurrence of mafic volcanic rocks, the “Taconite volcanics” (informal name), was discovered on northern Ellesmere Island between the head of Ayles Fiord and M’Clintock Inlet. The mainly alkali-picritic lavas are exposed within the central part of the Pearya Terrane as an outcrop in faulted contact with upper Carboniferous red beds of the Canyon Fiord Formation. The contact to the Ordovician island-arc volcanic rocks of the Pearya Terrane is unclear. The outcrop is characterized by a small circular magnetic anomaly. Ar–Ar whole-rock geochronology on the volcanic rocks yielded an age of 290 ± 19 Ma suggesting emplacement of the lavas during the early Permian. Whole rock geochemical analyses for eight samples revealed a geochemical affinity to ocean island basalt (OIB) and indicate variable mixing of low-degree melts in the fields of garnet and spinel peridotite (∼80–90 km depth). The involvement of a metasomatized subcontinental lithospheric mantle is indicated by high Pb, Nb, and Ta concentrations. Geochemical differences (as enrichments in Ti, Nb, Zr, and the light rare earth elements (REE)) to the known Carboniferous and Permian spilitic altered basalt occurrences of northwestern Ellesmere and northern Axel Heiberg islands are probably based on differences in the mantle source. The Sr isotope ratios of the Taconite volcanics are primitive ((87Sr/86Sr)t: 0.7037–0.7042) and its Nd isotope ratios are moderately depleted (εNd(t): +2.20 to +2.85) in contrast to the enriched εNd(t) values of the Permian Esayoo formation.

Targeting Ni-Cu mineralization in the Canadian High Arctic large igneous province: integrating geochemistry, magmatic architecture and structure

Mafic-ultramafic subvolcanic intrusive complexes, at the 1–10-km scale, constitute favorable environments for the formation of orthomagmatic Ni-Cu-PGE sulfide deposits. Within 100–1000-km scale large igneous provinces (LIPs), the most favorable economic target areas may be difficult to identify using a traditional regional exploration approach. We report results of field and laboratory studies focused on an integrated geochemical-architectural model for the Ni-Cu-PGE sulfide potential of the High Arctic large igneous province (HALIP) of Canada, the largest and best-exposed portion of this circum-arctic LIP. Previous lithogeochemical studies of the Canadian HALIP (130–80 Ma) concluded that subalkaline mafic units located on Axel Heiberg Island were more prospective than younger, alkalic igneous rocks (alkaline basalts to basanites) exposed on northern Ellesmere Island. Mapping carried out for this study revealed the presence of abundant subalkaline igneous rocks on western Ellesmere Island. We interpret these units as an extension of the Schei Sills, a stratigraphically bound sequence of intrusions exposed along a ~ N-S belt on eastern Axel Heiberg Island. Samples from the Schei Sills and from the Middle Fiord Intrusive Complex (~ 20 km2, central Axel Heiberg Island) show Cu/Zr values above and below unity, consistent with complementary sulfide enrichment and removal, respectively, within these intrusive systems. The spatial association of the Schei Sills with the post-emplacement Eocene Stolz Thrust is noteworthy, as later thrusting associated with the Paleogene Eurekan Orogeny caused the uplift of deeper parts of the HALIP subvolcanic feeder system and associated wall-rock stratigraphy. Absolute Ir-group PGE contents are low throughout the HALIP; however, Pt-group PGE contents range widely among analyzed tholeiitic intrusive rocks. For example, relatively elevated Pt + Pd values of 10–30 ppb in samples from the Middle Fiord Intrusive Complex and the Schei Sills suggest heightened prospectivity in these two areas. In contrast, tholeiitic flood basalts in the Strand Fiord Formation and associated intrusions exposed in western Axel Heiberg Island (~ 95 Ma) exhibit Cu/Zr < 1 and low Pt + Pd contents (below 10 ppb). The ca. 120 Ma magmatic event associated with the Schei Sills and Middle Fiord Intrusive Complex appears to have generated magmas that are more prospective than those of the younger (ca. 95 Ma) magmatic pulse associated with the flood basalts of the Strand Fiord Formation. This work demonstrates that not all architectural elements of a LIP are equal in terms of metallogenic potential, and that nested zones of higher prospectivity can be identified through the integration of several geological constraints.

Elemental composition, environment of deposition of the lower Carboniferous Emma Fiord formation oil shale in Arctic Canada

The sedimentary succession of 51-m consisting of a thin coal seam (1 m) and oil shale with a marlstone and carbonate-mudstone matrix of the Lower Carboniferous (Viséan) Emma Fiord Formation located on the Grinnell Peninsula, Devon Island, Arctic Canada was examined. The techniques used include reflected light microscopy, and instrumental neutron activation analysis (INAA) for elemental concentration, and inductively coupled plasma emission spectrometry (ICPES) for boron concentration.The coal and oil shale was deposited in a lacustrine, freshwater environment. Due to the climatic variation, two types of oil shale were developed based on the amount of precipitation. One with carbonate-mudstone matrix, with high calcite (75%) and low TOC (1.14–1.87%) content. The other a marlstone-dominated matrix with high aluminosilicate (64%) and TOC (16.4–53.6%) content.Oil shale from Emma Fiord experienced a slow rate of sedimentation and terrestrial flux as determined using Th/K/ Na/K, ratios Mn/Ca ratio to Ca respectively, and compared to the oil shale of Carboniferous age deposited in a lacustrine environment with a regular rate of recharge/discharge. The redox conditions for the Emma Fiord oil shale indicate anoxic to dysoxic conditions based on the variation of Cr and V + Ni.Thorium and U systematics indicate that U is more concentrated in oil shale with marlstone matrix and is associated with clay minerals and organic matter (OM), similar to the Carboniferous oil shale from the Big Marsh. The authigenic U is associated with TOC content and is higher for oil shale with the marlstone matrix.The variation of U with TOC indicates both paleo-productivity and preservation and is higher for oil shale with the marlstone matrix.The concentration of rare earth elements (REEs) is 95% due to the presence of light rare earth elements (LREEs) in both oil shale with marlstone and carbonate-mudstone matrices.The REES were normalized to the post-Archean average shale (PAAS). The high volatile bituminous coal at the base of the oil shale sections displays a flat, featureless pattern. The oil shale with a carbonate matrix decreases slightly from light rare earth elements (LREEs) to heavy rare earth elements (HREES). In contrast, the REEs concentration for oil shale with the marlstone matrix decreases more sharply from the LREEs (La-Eu) to HREEs (Tb-Lu). It displays a weak negative Eu anomaly typical of the upper continental crust.

Trilobite fauna of the Telt Bugt Formation (Cambrian Series 2–Miaolingian Series), western North Greenland (Laurentia)

Trilobites dominantly of middle Cambrian (Miaolingian Series, Wuliuan Stage) age are described from the Telt Bugt Formation of Daugaard-Jensen Land, western North Greenland (Laurentia), which is a correlative of the Cape Wood Formation of Inglefield Land and Ellesmere Island, Nunavut. Four biozones are recognised in Daugaard-Jensen Land, representing the Delamaran and Topazan regional stages of the western USA. The basal Plagiura–Poliella Biozone, with Mexicella cf. robusta, Kochiella, Fieldaspis? and Plagiura?, straddles the Cambrian Series 2–Miaolingian Series boundary. It is overlain by the Mexicella mexicana Biozone, recognised for the first time in Greenland, with rare specimens of Caborcella arrojosensis. The Glossopleura walcotti Biozone, with Glossopleura, Clavaspidella and Polypleuraspis, dominates the succession in eastern Daugaard-Jensen Land but is seemingly not represented in the type section in western outcrops, likely reflecting the drastic thinning of the formation towards the north-west. The Ehmaniella Biozone, with Ehmaniella, Clappaspsis, Blainia and Blainiopsis, is the youngest recognised biozone. The presence of Drumian Stage strata reported elsewhere in North Greenland and adjacent Ellesmere Island has not been confirmed in Daugaard-Jensen Land. Lower beds of the Cass Fjord Formation, which directly overlie the Telt Bugt Formation, are assigned to the Guzhangian Stage. New species: Fieldaspis? iubilaei, Ehmaniella tupeqarfik.

New constraints on the age, geochemistry, and environmental impact of High Arctic Large Igneous Province magmatism: Tracing the extension of the Alpha Ridge onto Ellesmere Island, Canada

Abstract The High Arctic Large Igneous Province (HALIP) represents extensive Cretaceous magmatism throughout the circum-Arctic borderlands and within the Arctic Ocean (e.g., the Alpha-Mendeleev Ridge). Recent aeromagnetic data shows anomalies that extend from the Alpha Ridge onto the northern coast of Ellesmere Island, Nunavut, Canada. To test this linkage we present new bulk rock major and trace element geochemistry, and mineral compositions for clinopyroxene, plagioclase, and olivine of basaltic dykes and sheets and rhyolitic lavas for the stratotype section at Hansen Point, which coincides geographically with the magnetic anomaly at northern Ellesmere Island. New U-Pb chronology is also presented. The basaltic and basaltic-andesite dykes and sheets at Hansen Point are all evolved with 5.5–2.5 wt% MgO, 48.3–57.0 wt% SiO2, and have light rare-earth element enriched patterns. They classify as tholeiites and in Th/Yb vs. Nb/Yb space they define a trend extending from the mantle array toward upper continental crust. This trend, also including a rhyolite lava, can be modeled successfully by assimilation and fractional crystallization. The U-Pb data for a dacite sample, that is cut by basaltic dykes at Hansen Point, yields a crystallization age of 95.5 ± 1.0 Ma, and also shows crustal inheritance. The chronology and the geochemistry of the Hansen Point samples are correlative with the basaltic lavas, sills, and dykes of the Strand Fiord Formation on Axel Heiberg Island, Nunavut, Canada. In contrast, a new U-Pb age for an alkaline syenite at Audhild Bay is significantly younger at 79.5 ± 0.5 Ma, and correlative to alkaline basalts and rhyolites from other locations of northern Ellesmere Island (Audhild Bay, Philips Inlet, and Yelverton Bay West; 83–73 Ma). We propose these volcanic occurrences be referred to collectively as the Audhild Bay alkaline suite (ABAS). In this revised nomenclature, the rocks of Hansen Point stratotype and other tholeiitic rocks are ascribed to the Hansen Point tholeiitic suite (HPTS) that was emplaced at 97–93 Ma. We suggest this subdivision into suites replace the collective term Hansen Point volcanic complex. The few dredge samples of alkali basalt available from the top of the Alpha Ridge are akin to ABAS in terms of geochemistry. Our revised dates also suggest that the HPTS and Strand Fiord Formation volcanic rocks may be the hypothesized subaerial large igneous province eruption that drove the Cretaceous Ocean Anoxic Event 2.

P.354 Bloomed again: seasonality and clinical correlates in bipolar disorder

Important depositional characteristics indicative of climate change has been discovered in 50-m sedimentary succession consisting of oil shales with a marlstone and carbonate matrix of the Viséan shales from the Lower Carboniferous Emma Fiord Formation on Devon Island, Canada's Arctic Archipelago. Older Carboniferous (Tournaisian) shales, are however absent from Devon Island, but elsewhere such as Big Marsh, Nova Scotia, Tournaisian shales show no comparable evidence for climate change.The techniques used include reflected light microscopy, RockEval analyses, instrumental neutron activation analysis (INAA) for elemental concentration.Indeed, Viséan shales from the Lower part the Emma Fiord Formation from Devon Island have a marlstone matrix with abundant algal matter. The matrix also has low carbonate (32%) and total organic carbon (TOC) content between 33.3%and 55.6%. Moreover, the TOC show a positive correlation with authigenic uranium, and Mo, which suggests a high productivity due to the high rain, deeper water lacustrine depositional environment. Other Viséan oil shales from the Emma Fiord Formation on Devon Island have somewhat different characteristics from those with marlstone matrix. Indeed, they have a high (75%) carbonate content with calcified algal matter and low TOC (1.14–17.4%). A very low correlation between TOC and authigenic U, and Mo. Most importantly very high oil generation (98–413 L/t) potential of marlstones as compared to low yield of carbonate mudstones (4.1–17.0 L/t) shows a dramatic climatic shift to low precipitation and much dryer conditions. Such a drastic climatic condition has not been detected for the Tournaisian oil shales.

A climate change event, detected in Viséan oil shales from Devon Island, Arctic Canada

Important depositional characteristics indicative of climate change has been discovered in 50-m sedimentary succession consisting of oil shales with a marlstone and carbonate matrix of the Viséan shales from the Lower Carboniferous Emma Fiord Formation on Devon Island, Canada's Arctic Archipelago. Older Carboniferous (Tournaisian) shales, are however absent from Devon Island, but elsewhere such as Big Marsh, Nova Scotia, Tournaisian shales show no comparable evidence for climate change.The techniques used include reflected light microscopy, RockEval analyses, instrumental neutron activation analysis (INAA) for elemental concentration.Indeed, Viséan shales from the Lower part the Emma Fiord Formation from Devon Island have a marlstone matrix with abundant algal matter. The matrix also has low carbonate (32%) and total organic carbon (TOC) content between 33.3%and 55.6%. Moreover, the TOC show a positive correlation with authigenic uranium, and Mo, which suggests a high productivity due to the high rain, deeper water lacustrine depositional environment. Other Viséan oil shales from the Emma Fiord Formation on Devon Island have somewhat different characteristics from those with marlstone matrix. Indeed, they have a high (75%) carbonate content with calcified algal matter and low TOC (1.14–17.4%). A very low correlation between TOC and authigenic U, and Mo. Most importantly very high oil generation (98–413 L/t) potential of marlstones as compared to low yield of carbonate mudstones (4.1–17.0 L/t) shows a dramatic climatic shift to low precipitation and much dryer conditions. Such a drastic climatic condition has not been detected for the Tournaisian oil shales.

Controls on the formation of microbially induced sedimentary structures and biotic recovery in the Lower Triassic of Arctic Canada

Abstract Microbially induced sedimentary structures (MISS) are reportedly widespread in the Early Triassic and their occurrence is attributed to either the extinction of marine grazers (allowing mat preservation) during the Permo-Triassic mass extinction or the suppression of grazing due to harsh, oxygen-poor conditions in its aftermath. Here we report on the abundant occurrence of MISS in the Lower Triassic Blind Fiord Formation of the Sverdrup Basin, Arctic Canada. Sedimentological analysis shows that mid-shelf settings were dominated by deposition from cohesive sand-mud flows that produced heterolithic, rippled sandstone facies that pass down dip into laminated siltstones and ultimately basinal mudrocks. The absence of storm beds and any other “event beds” points to an unusual climatic regime of humid, quiet conditions characterized by near continuous run off. Geochemical proxies for oxygenation (Mo/Al, Th/U, and pyrite framboid analysis) indicate that lower dysoxic conditions prevailed in the basin for much of the Early Triassic. The resultant lack of bioturbation allowed the development and preservation of MISS, including wrinkle structures and bubble textures. The microbial mats responsible for these structures are envisaged to have thrived, on sandy substrates, within the photic zone, in oxygen-poor conditions. The dysoxic history was punctuated by better-oxygenated phases, which coincide with the loss of MISS. Thus, Permo-Triassic boundary and Griesbachian mudrocks from the deepest-water settings have common benthos and a well-developed, tiered burrow profile dominated by Phycosiphon. The presence of the intense burrowing in the earliest Triassic contradicts the notion that bioturbation was severely suppressed at this time due to extinction losses at the end of the Permian. The notion that Early Triassic MISS preservation was caused by the extinction of mat grazers is not tenable.

Unusual preservation of an Ordovician (Floian) arthropod from Peary Land, North Greenland (Laurentia)

Preservation of a fragment of an arthropod from starved trough sediments of the Bøggild Fjord Formation (Ordovician, Floian) of Johannes V. Jensen Land in north Peary Land, North Greenland, recalls that of the lower Cambrian Sirius Passet Lagerstätte of extreme north-west Peary Land and may suggest a second locality for exceptional preservation in North Greenland. A prominent petaloid pattern on the tergopleurae reflects impression onto the internal mould of terrace lines from the cuticle exterior. The arthropod is associated with poorly preserved sponges and a depauperate assemblage of organic-walled microfossils. It is tentatively compared to Mollisonia, originally described from the Burgess Shale Lagerstätte (middle Cambrian, Miaolingian Series) of Canada.

The timing of fjord formation and early glaciations in North and Northeast Greenland

The timing of fjord formation and early glaciations in North and Northeast Greenland

Influence of the High Arctic Igneous Province on the Cenomanian/Turonian boundary interval, Sverdrup Basin, High Canadian Arctic

Emplacement of Large Igneous Provinces (LIPs) had a major effect on global climate, ocean chemistries as traced in sedimentary records and biotic turnovers. The linkage between LIPs and oceanic anoxic events has been documented with the Cenomanian/Turonian boundary event and Oceanic Anoxic Event 2 (OAE2). The Caribbean LIP and High Arctic Large Igneous Province (HALIP) are regarded as possible triggers. The pericratonic Arctic Sverdrup Basin is the partial location of the HALIP, where little is known about sedimentary, geochemical and biotic responses to the HALIP phases. Sedimentary strata at Glacier Fiord, Axel Heiberg Island, exhibit a dynamic Cretaceous polar carbon burial history within the lower to middle Cenomanian Bastion Ridge Formation and upper Cenomanian to Turonian part of the Kanguk Formation. We present the first initial 187Os/188Os (Osi) composition profile for a polar Cenomanian/Turonian boundary interval (∼100–93.9 Ma) linked to recently dated magmatic phases of the Strand Fiord Formation, part of the HALIP. The carbon isotope record coupled with the Osi profile show two events in the upper Cenomanian interval marked by positive carbon perturbations and shifts to more non-radiogenic Osi compositions. The earlier short-lived event is interpreted as result of weathering of the surrounding Strand Fiord volcanics causing a local non-radiogenic Osi signal. Coinciding transgressive shorelines let to an increase in marine and terrestrially derived organic matter. Subsequently, injection of mantle-derived basalts into organic rich sediments is credited with causing the release of methane documented in a distinct negative carbon isotope excursion. We speculate that the methane release of the HALIP was an important contribution for rapid global warming caused by increasing atmospheric CO2 levels associated with the OAE2 event likewise recognized in the Sverdrup Basin. As climate cooled in the middle and late Turonian, carbon burial decreased under increasingly oxygenated benthic conditions. Epifaunal foraminiferal species, adapted to low oxygen conditions, persisted during the OAE2. Our Cenomanian to Turonian multiproxy record of the Sverdrup Basin distinguishes between local and global signals within a restricted High Arctic basin. Our results demonstrate the interplay between basin tectonism and sea-level change, increased weathering during transgressive phases, seafloor processes such as hydrothermal activity and methane release and biotic response to a complex paleoceanography. With future reliable dated frameworks this unique polar record will facilitate correlations to other polar basins and records of lower paleolatitudes.

Ceratodus tunuensis, sp. nov., a new lungfish (Sarcopterygii, Dipnoi) from the Upper Triassic of central East Greenland

ABSTRACTThe fossil record of post-Paleozoic lungfishes in Greenland is currently restricted to a few brief reports of isolated and undetermined tooth plates coming from the uppermost Fleming Fjord Formation (late Norian) in Jameson Land, central East Greenland. Here, we describe Ceratodus tunuensis, sp. nov., a new dipnoan from a thin bed of calcareous lake mudstone from the Ørsted Dal Member of the Fleming Fjord Formation. The Ceratodus fossil record indicates that during the Late Triassic, this genus was restricted to the middle latitudes of the Northern Hemisphere. This record matches previous paleobiogeographical analyses and indicates that terrestrial biota during the Late Triassic was strongly influenced by paleolatitude.Citation for this article: Agnolin, F. L., O. Mateus, J. Milàn, M. Marzola, O. Wings, J. Schulz Adolfssen, and L. B. Clemmensen. 2018. Ceratodus tunuensis, sp. nov., a new lungfish (Sarcopterygii, Dipnoi) from the Upper Triassic of central East Greenland. Journal of Vertebrate Paleontology. DOI: 10.1080/02724634.2018.1439834.

A review of Palaeozoic and Mesozoic tetrapods from Greenland

This article presents a synthesis of Palaeozoic and Mesozoic fossil tetrapods from Greenland, including an updated review of the holotypes and a new photographic record of the main specimens. All fossil tetrapods found are from East Greenland, with at least 30 different known taxa: five stem tetrapods (Acanthostega gunnari, Ichthyostega eigili, I. stensioi, I. watsoni, and Ymeria denticulata) from the Late Devonian of the Aina Dal and Britta Dal Formations; four temnospondyl amphibians (Aquiloniferus kochi, Selenocara groenlandica, Stoschiosaurus nielseni, and Tupilakosaurus heilmani) from the Early Triassic of the Wordie Creek Group; two temnospondyls (Cyclotosaurus naraserluki and Gerrothorax cf. pulcherrimus), one testudinatan (cf. Proganochelys), two stagonolepids (Aetosaurus ferratus and Paratypothorax andressorum), the eudimorphodontid Arcticodactylus, undetermined archosaurs (phytosaurs and both sauropodomorph and theropod dinosaurs), the cynodont Mitredon cromptoni, and three mammals (Haramiyavia clemmenseni, Kuehneotherium, and cf. ?Brachyzostrodon), from the Late Triassic of the Fleming Fjord Formation; one plesiosaur from the Early Jurassic of the Kap Stewart Formation; one plesiosaur and one ichthyosaur from the Late Jurassic of the Kap Leslie Formation, plus a previously unreported Late Jurassic plesiosaur from Kronprins Christian Land. Moreover, fossil tetrapod trackways are known from the Late Carboniferous (morphotype Limnopus) of the Mesters Vig Formation and at least four different morphologies (such as the crocodylomorph Brachychirotherium, the auropodomorph Eosauropus and Evazoum, and the theropodian Grallator) associated to archosaurian trackmakers are known from the Late Triassic of the Fleming Fjord Formation. The presence of rich fossiliferous tetrapod sites in East Greenland is linked to the presence of well-exposed continental and shallow marine deposits with most finds in terrestrial deposits from the Late Devonian and the Late Triassic.

Cretaceous basalts of the High Arctic large igneous province at Axel Heiberg Island (Canada): Volcanic stratigraphy, geodynamic setting, and origin

The Cretaceous (Cenomanian, ~96 Ma) basaltic rocks of the Strand Fiord Formation of the Sverdrup Basin of the Canadian Arctic Archipelago, Nunavut, Canada, are a part of the High Arctic large igneous province. The basaltic suite reaches a thickness of almost 1,000 m on Axel Heiberg Island in its depocentre and over 700 m at the studied section. The rocks are variably fractionated tholeiitic basalts, which are geochemically similar to many other continental flood basalts, particularly to low Ti basalts of flood basalt provinces. Geochemical as well as Sr (87Sr/86Srinitial~ 0.7045 to 0.7067) and Nd (ƐNd(t)~ +1.3 to +4.3) isotopic signatures of the basalts were inherited during partial melting of spinel peridotite of an ancient subcontinental lithospheric mantle, which was modified around 0.7–0.9 Ga by a metasomatic event. The melting generating the Cretaceous basalts was probably triggered by a mantle plume but was also associated with basin rifting and stretching. There is evidence of plume‐induced doming and uplift of the crust prior to and during the eruption of the basalts as documented by the progression from marine sedimentation to subaerial/lacustrine and then back to marine sedimentation in the Sverdrup Basin centre. The basalts represent parts of the Early Cretaceous igneous province that is dispersed around the Arctic Ocean due to the opening of the Canada Basin, which is inferred to be related to a mantle plume.

Upper Paleozoic hydrocarbon systems in the Sverdrup Basin, Canadian Arctic Islands

Abstract The upper Paleozoic (Carboniferous to Permian) succession of the Sverdrup Basin in the Canadian Arctic Islands has the potential to contain significant hydrocarbon reserves, though it has never been a primary exploration target. To better constrain previous estimates and hydrocarbon play possibilities, this study completed evaluations of source rock quality and extent and thermal maturity. This study also incorporated new understandings of reservoir units and their stratigraphic relation to source rocks, trapping configurations and timing of hydrocarbon migration. Several hydrocarbon source units were identified within the upper Paleozoic formations of the Sverdrup Basin including the Emma Fiord, Trappers Cove, Antoinette, Assistance, Sabine Bay, van Hauen and Trold Fiord formations. The Emma Fiord and Trold Fiord formations are both found to be oil prone, with the remainder of the sources being gas prone. The upper Paleozoic succession is interpreted to be gas prone due to dominant kerogen types and high average thermal maturity. Many of the older concept plays put forth for the upper Paleozoic succession have been determined to be unviable. However, modern plays that implement new understandings of the basin have the potential to be viable. This study has found that the upper Paleozoic succession of the Sverdrup Basin is promising for gas discoveries with new plays such as salt diapirism plays, or plays similar to the Barents Sea Gohta play. New hydrocarbon rock source data also suggests the potential for a new oil and gas play on northern Prince Patrick Island. This new research could lead to significant resource discoveries that have been previously overlooked.

Intersecting fold belts in the Bathurst Island region, Nunavut

The Bathurst Island archipelago in the central part of the Canadian Arctic Islands, includes Bathurst Island proper and six other significant islands to north and west. This is the site of two intersecting fold belts: the northerly-trending Cornwallis Fold Belt and the westerly-trending Parry Islands Fold BeltSignificant components of the report area include Precambrian seismic basement, the Franklinian shelf (Cambrian to Devonian), a Middle and Upper Devonian clastic wedge, and outliers of the Sverdrup Basin (Carboniferous-Cretaceous). Total thickness of the Cambrian to Devonian succession is 7.6–8.8 km in the island group. Oldest identified strata are evaporites of the Middle Ordovician Bay Fiord Formation. These form a ductile decollement zone that at a depth of 4100–5500 m everywhere underlies thrust-folds. Above this are shelf carbonates, deep water mudrocks, and shallow to deep water strata associated with tectonic activity through the upper Silurian to Lower Devonian Cornwallis Fold Belt. The end of uplift-related deposition is marked by a transition to basin fill mudrocks, succeeded in the later Devonian by shelf-deltaic and fluvial sandstones and other clastic rocks.Structures of Cornwallis Fold Belt feature north and in part west-striking thrust panels and evidence of unroofing in early Ludlow to mid-Emsian time. Also included are westerly-transported thrusts kinematically linked to easterly- striking wrench faults that are presumably reactivated as thrusts and forming large interference structures during development of Parry Islands Fold Belt deformation in the Late Devonian to early Carboniferous. Parry Islands Fold Belt features upright surface folds, subsurface thrusts, ductile deformation and detachment in Ordovician salt and Devonian shale. Structures include northerly- and southerly-transported thrusts, zig-zag structures, pop-up and pop-down structures.

U-Pb geochronology of the plumbing system associated with the Late Cretaceous Strand Fiord Formation, Axel Heiberg Island, Canada: part of the 130-90 Ma High Arctic large igneous province

The c. 130-90 Ma High Arctic Large Igneous Province (HALIP) greatly influenced the geological evolution of Canada’s Arctic Islands along with formerly adjacent Svalbard (Norway), Franz Josef Land (Russia) and offshore regions such as the Alpha-Mendeleev Ridge. Three subalkaline tholeiitic pulses constitute the HALIP: (1) an initial two pulses at ca. 120–130 Ma in the Canadian portion are temporally associated with the Isachsen Formation basalts, and a later pulse at ca. 95–100 Ma fed extensive flood basalt lavas of the Strand Fiord Formation. Fieldwork at South Fiord on Axel Heiberg Island revealed a small network of sills and dykes. The U-Pb ID-TIMS baddeleyite age for diabase from a >10 m SSE-trending dyke (sample 13-CK-16) is 95.18 ± 0.35 Ma (2σ) and for a gabbro from a >50 m thick sill ∼7 km to the dyke’s SW (sample 13-WJA-C028-A2) is 95.41 ± 0.12 Ma (2σ), identical within stated uncertainties. The two ages, in tandem with the similar geochemistry of the intrusions and Strand Fiord Formation lavas, provide the first precise age constraints for the feeder system of the Strand Fiord Formation which represents the younger pulse of HALIP. The two samples are distinct from each other in their Sm-Nd isotopic values suggesting they were derived from separate batches of magma that fed separate eruptive episodes.

Cyclotosaurus naraserluki, sp. nov., a new Late Triassic cyclotosaurid (Amphibia, Temnospondyli) from the Fleming Fjord Formation of the Jameson Land Basin (East Greenland)

ABSTRACT Cyclotosaurus naraserluki, sp. nov., is a new Late Triassic capitosaurid amphibian from lacustrine deposits in the Fleming Fjord Formation of the Jameson Land Basin in Greenland. It is based on a fairly complete and well-preserved skull associated with two vertebral intercentra. Previously reported as Cyclotosaurus cf. posthumus, C. naraserluki is unique among cyclotosaurs for having the postorbitals embaying the supratemporals posteromedially. The anterior palatal vacuity presents an autapomorphic complete subdivision by a wide medial premaxillary-vomerine bony connection. The parasphenoid projects between the pterygoids and the exoccipitals, preventing a suture between the two, a primitive condition shared with Rhinesuchidae, Eryosuchus, and Kupferzellia. Within Cyclotosaurus, the Greenlandic skull has a distinctive combination of circular choanae (shared with C. ebrachensis, C. posthumus, and C. robustus) and a convex posteromedial margin of the tabulars (also present in C. ebrachensis and C. intermedius). A phylogenetic analysis indicates that C. naraserluki is the sister taxon of the middle Norian C. mordax from southern Germany, with which it shares a pair of premaxillary foramina. Cyclotosaurus is one of the most successful and diverse genera of Late Triassic temnospondyls, with at least eight species reported from middle Carnian to late Norian. Cyclotosaurus naraserluki is the largest amphibian ever reported from Greenland and one of the Late Triassic vertebrates with the highest northern paleolatitude currently known. http://zoobank.org/urn:lsid:zoobank.org:pub:43AAA541-031C-4EE1-B819-4846EBBD1BBB SUPPLEMENTAL DATA—Supplemental materials are available for this article for free at www.tandfonline.com/UJVP Citation for this article: Marzola, M., O. Mateus, N. H. Shubin, and L. B. Clemmensen. 2017. Cyclotosaurus naraserluki, sp. nov., a new Late Triassic cyclotosaurid (Amphibia, Temnospondyli) from the Fleming Fjord Formation of the Jameson Land Basin (East Greenland). Journal of Vertebrate Paleontology. DOI: 10.1080/02724634.2017.1303501.

Sauropodomorph dinosaur trackways from the Fleming Fjord Formation of East Greenland: evidence for Late Triassic sauropods

Sauropodomorph dinosaur trackways from the Fleming Fjord Formation of East Greenland: evidence for Late Triassic sauropods

Miocene deposits at Silkeborg, Jylland, and their influence on hydrology

A motorway was constructed in 2010–2016 through the suburbs of the city of Silkeborg (Fig. 1). The Danish Road Directorate wished to climate-proof the motorway against adverse future climate changes. The directorate collaborated with the Geological Survey of Denmark and Greenland (GEUS) to study the hydrological conditions. Studies of historical and projected climate-change-driven variations in groundwater levels in relation to urbanised hydrological fluxes were conducted by Kidmose et al. (2013, 2015). During the construction of the motorway, Miocene and Quaternary deposits were exposed in the slopes of the Gudenå valley and late-glacial glaciofluvial deposits were found in the valley floor. This paper focuses on the Miocene sediments and their influence on the local hydrological conditions.&#x0D; At Silkeborg the Gudenå valley is c. 35 m deep (Fig. 1). The surrounding terrain is a till plain. In the slope of the valley, glaciofluvial sand is found below the till. Miocene deposits are found below the glaciofluvial sand. The floor of the Gudenå valley is covered by c. 15 m thick glaciofluvial deposits, which rest on Miocene deposits. In borehole no. DGU 87.907 49 m of Miocene deposits belonging to the Vejle Fjord Formation are recorded, consisting primarily of marine clay with minor occurrences of sandy deposits. About 12 km south of Silkeborg lower Miocene deposits are seen in outcrops and boreholes (Fig. 2). Here the fluvial Addit Member of the Billund Formation (Rasmussen et al. 2010) is separated from the underlying marine Vejle Fjord Formation by a sharp erosional contact (Rasmussen 2014).