Browsing by Author "Beauchamp, Benoit"
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- ItemOpen AccessCharacteristics of an Icing-Dammed Proglacial Lake(2017) Blade, Michelle; Moorman, Brian; Beauchamp, Benoit; Sjogren, DarrenIcing-dammed proglacial lakes form as a result of water-flow pathway restrictions caused by freezing of winter baseflow. With the majority of glaciers in the eastern Canadian High Arctic that previously terminated at sea level now terminating on land (Vaughan et al., 2013), emerging proglacial environments are becoming more common - resulting in the occurrence of novel terrestrial proglacial water flow regimes. This research addressed the knowledge gap of how a glacier, proglacial environment, and hydrological cycle contribute to delayed water-flow, in the form of a proglacial icing-dammed lake, in the terrestrial proglacial environment. The research was conducted at a unique location on Bylot Island, NU, in the eastern Canadian High Arctic, where icing-dammed proglacial lakes have been observed to form multiple years prior. In the proglacial environment, icing development has been studied as proxies to infer winter baseflow from upvalley glacial hydrological networks (Hodgkins et al., 2004; Wainstein, 2011). In addition, icing ablation has been studied as it reallocates a portion of winter streamflow to summer streamflow via icing melt (Reedyk et al., 1995). But icing-dammed lake formation in the proglacial environment remains relatively unexplored due to the uniqueness of their formation. Direct observations, time-lapse photography, lake water level and temperature monitoring, lake bathymetric mapping, and meteorological, electrical conductivity, turbidity, and dye tracing measurements were used to examine the characteristics of an icing-dammed proglacial lake to infer the processes involved for its formation and preservation into the July 2014 summer melt season. Results suggest that the icing-dammed proglacial lake formation is dependent on: the previous year’s icing state at the end of the melt season; the current icing forming a seal with the surrounding topography to restrict water flow and raise local base water level; and the current year’s melt season flow regime not exceptionally exceeding the current icing’s melt thereby allowing water to pool and form a lake.
- ItemOpen AccessControls on the Timing and Evolution of Deep-Water Sedimentation in the Late Cretaceous Nanaimo Basin, British Columbia, Canada(2017) Englert, Rebecca Gail; Hubbard, Stephen; Leckie, Dale; Beauchamp, BenoitSubmarine channel-system deposits of the Late Cretaceous Nanaimo Group, British Columbia, Canada record long-lived (>10^6 yr) deep-water sedimentation across a tectonically active basin margin. The integration of detrital zircon geochronology and stratigraphic analyses provides a unique opportunity to characterize the paleogeographic setting, source-to-sink relationships, and temporal evolution of this ancient sediment-routing system. Three contemporaneous conglomeratic channel-levee deposits are documented across a 135-km basin margin (strike-oriented) transect, indicating a period of widespread deep-water sedimentation. At one of these locations, continuous sediment transfer occurred for 21.1 ± 3.4 m.y. through an established submarine conduit that underwent a period of prolonged sediment bypass followed by a phase of channel aggradation. The timing and nature of deposition along the paleo-basin margin relates to geomorphic and tectonic changes in the basin and upstream drainage-systems, suggesting localized and regional controls on deep-water sediment delivery. These deposits provide insight into the geologic history of North America and sediment dispersal in tectonically active settings globally.
- ItemOpen AccessDepositional History and Petroleum Potential of the Middle Devonian Fort Vermilion Formation, Alberta(2023-11-20) Heath, Danica Pearl; Beauchamp, Benoit; Henderson, Charles Murray; Dewing, KeithThe Devonian Fort Vermilion Formation in the Swan Hills area of Alberta comprises interbedded anhydrite and carbonates. Generally interpreted as being formed subaerially in a sabkha environment, a new depositional model is proposed for this unit whereby sedimentation occurred subaqueous in a protected, variably deep, restricted basin. Based upon core examination, petrography, and various geochemical analyses, four facies assemblages representing four environments were identified: restricted and hypersaline, early diagenetic, moderately restricted, and euhaline. Three models, differing primarily on scale and proximity to the marine environment are discussed; these are: i) salina; ii) restricted lagoon; and iii) lake. The evidence garnered through this study are most consistent with deposition in a hypersaline lagoon setting, cut off from the open marine environment. Early deposition was most restricted with fluctuating water chemistry resulting in the deposition of carbonate and evaporite units. Seawater and associated ions were supplied to the system via evaporative drawdown through a seaward barrier or tidal channels. Relative sea level rise resulted in a better connection with the open ocean and the end of evaporite deposition, though salinity-restricted conditions persisted, as demonstrated by a paucity of marine biota. Following further sea level rise normal marine conditions ensued. The petroleum potential of the Fort Vermilion Formation was also investigated, though it was determined that the absence of organic matter (indicated by very low TOC values) prevented the generation of any substantial amount of hydrocarbons.
- ItemOpen AccessDepositional, Diagenetic and Structural History of the Devonian Succession beneath the Athabasca Oil Sands of Northern Alberta(2018-08-15) Garroni, Nicolas; Beauchamp, Benoit; Meyer, Rudi; Henderson, Charles MurrayThree lengths of core with a cumulative total of 1038 m from the Devonian succession beneath the Athabasca oil sands in northeastern Alberta were studied in detail to better understand the depositional, diagenetic and structural history of these rocks, and ultimately to provide insights into the origin and timing of karsting in the region. The succession in the study area encompasses ten formations as well as the Precambrian crystalline basement. Facies analysis based on megascopic and microscopic observations was performed to interpret the depositional environment of each formation. Depositional environments of variable settings and bathymetry range from fluvial sandstone to basinal carbonate. Diagenetic features were also recorded for each unit, from the time of deposition to present day. Thirty-one diagenetic features were identified, their origins interpreted and integrated in elaborate paragenetic sequences for the entire succession. Additional geochemical analysis helped reinforce initial interpretations based on thin section petrography. Dissolution and thermochemical sulfate reduction of thick evaporite deposits are interpreted to have caused both karsting in the overlying sediments and extensive recrystallization of the underlying carbonates. A fault in the region, likely rooted in the crystalline basement, may have enhanced certain diagenetic processes as well as the removal of evaporites.
- ItemOpen AccessDetrital Zircon Geochronology of the Queen Charlotte Group, Haida Gwaii, British Columbia(2019-01-17) Dorsey, Cameron; Hubbard, Stephen M.; Matthews, William A.; Hadlari, Thomas; Beauchamp, BenoitMarine clastic strata of the Queen Charlotte Group (QCG), exposed within Skidegate Inlet on Haida Gwaii, British Columbia, Canada, provide a comprehensive stratigraphic record of Cretaceous forearc deposition on the Wrangellia Terrane. These exposures include the Aptian to Campanian Longarm, Haida, Skidegate, Honna, and Tarundl formations. Detrital zircons from these strata provide a unique opportunity to test linkages between the Wrangellia-Alexander, Taku and Yukon-Tanana terranes in the Cretaceous. Twelve samples were collected through the Cretaceous stratigraphic succession and 300 U-Pb measurements were obtained for each sample by LA-ICP-MS. Detrital zircon populations are dominated by two Mesozoic sub-populations with modes at ~150 Ma and ~90 Ma. These ages indicate QCG strata derive predominantly from rocks of the northwest Coast Plutonic Complex (CPC) to the east where rocks of this age are common. A small but consistent Paleozoic (~400 to 430 Ma) population in samples from the Longarm, Haida, Skidegate and Honna formations suggests a linkage to the Alexander Terrane during the Early to Late-Cretaceous. The youngest strata sampled, the Latest Campanian Tarundl Formation, yielded detrital zircons with complex U-Pb systematics indicative of inheritance. Cores from the Tarundl Formation yield dates of 300-400 Ma and 1000-2800 Ma, similar to sedimentary rocks of the Yukon-Tanana Terrane. Zircon rims within the youngest sub-population yield a single age (86.7 ± 1.2 Ma; MSWD 8.0) suggesting the Tarundl Formation derives from a restricted source area and potentially a single magmatic body. The ages of inherited cores indicate this source likely intruded rocks of the Yukon-Tanana Terrane such as the basal Port Houghton assemblage. Maximum depositional ages (MDAs) indicate syn-magmatic sedimentation from the Aptian to Campanian, which is consistent with biostratigraphic age constraints (e.g. McLearn, 1972; Haggart, 1991; Haggart, 2009). However, clustering of the MDA suggests punctuated sedimentation that was likely deposited by migrating channel systems. Detrital zircon ages from rocks of the QCG indicate derivation was from source areas located west of the Coast Shear Zone (CSZ). Therefore, a linkage to sources east of the CSZ is not necessary to explain provenance for the Queen Charlotte Group.
- ItemOpen AccessEarly Cretaceous methane seepage system and associated carbonates, biota and geochemistry, Sverdrup Basin, Ellef Ringnes Island, Nunavut(2013-10-02) Williscroft, Krista; Beauchamp, Benoit; Grasby, StephenOver one hundred carbonate deposits, interpreted as having formed at methane seepage sites in the Sverdrup Basin have been discovered on Ellef Ringnes Island, Canadian Arctic. The deposits, up to 2.7 metres tall and 60 metres wide, are found within the lower member of the Lower Cretaceous Christopher Formation, a silty marine shale. The carbonates have complex and heterogeneous structures typical of seep carbonates, including banded botryoidal and clotted textures as well as void filling sparite. Stable carbon isotopes show highly 13C-depleted values, as low as δ13CVPDB = -53‰, indicative of authigenic carbonate precipitation via the anaerobic oxidation of biogenic methane. Abundant and well-preserved fauna include multiple species of bivalves, worm tubes, ammonites and gastropods. Methane seepage is calculated to have lasted ~500,000 years and was brought about by a tensional stress regime as well as salt diapirism related faulting.
- ItemOpen AccessForaminiferal Biostratigraphy in Proximity to the Albian/Cenomanian Boundary using Six Global Deep Sea Drilling Project Sites(2016) Sawyer, Melissa Slavka; Georgescu, Marius Dan; Henderson, Charles; Beauchamp, Benoit; Anderson, Jason; Theodor, JessicaThe Cretaceous stages are poorly defined and inconsistencies in the named species of the lowermost Cenomanian biozone and rarity of other named species led to doubt over the current biozonation scheme and its validity. This study tests the previous biozonation definitions through a review of planktic foraminifera from six global Deep Sea Drilling Project sites. This study validates the use of T. globotruncanoides as the named species for the lowermost Cenomanian biozone despite the location of the referenced type specimen not being from the type locality. Several changes were applied to the biozonation of the late Albian; however, the named species Pseudothalmanninella ticinensis was not observed and a new biozone, Clavihedbergella subcretacea was assigned. Trends observed in the lower P. appenninica Biozone lead to the recognition of a new biozone, P. buxtorfi. These findings support the Cenomanian stage definition and help to define the Albian stage.
- ItemOpen AccessLate Pennsylvanian-Early Permian Stratigraphy, Sedimentology and Paleoceanography of the Sverdrup Basin, NW Ellesmere Island, Arctic Canada(2016) Calvo Gonzalez, Daniel; Beauchamp, Benoit; Henderson, Charles Murray; Dutchak, Alexander; Dewing, KeithThe Pennsylvanian-Early Permian carbonate succession of the Sverdrup Basin was studied in Otto Fiord, northwest Ellesmere Island. Seven sections containing shelf carbonates and slope mudrocks and chert were analyzed. The Gzhelian-Kungurian sequence stratigraphy of the basin was revisited based on microfacies analysis and field observations performed in these sections. Two new unconformity-bounded T-R sequences were defined: 1) Sakmarian: composed of the Raanes and contemporaneous Hare Fiord formations; and 2) Artinskian: formed by the Trappers Cove and the bulk of the Great Bear Cape formations. Furthermore, the warm- to cool-water transition in carbonate sedimentation in the basin was analyzed. Based on microfacies analysis of samples from the Nansen and Raanes formations the origin and timing of this shift in sedimentation was discussed. Global warming-enhanced upwelling in Panthalassa is here suggested to be the trigger for this transition. This global warming marks the end of the Late Palaeozoic Ice Age.
- ItemOpen AccessLower Permian (Sakmarian) Cool-water Microbial Carbonate Mounds of the Sverdrup Basin(2017) Pelletier, Eric; Beauchamp, Benoit; Henderson, Charles; Dutchak, AlexThe Sverdrup Basin in the Canadian Arctic records a shift from warm-water photozoan carbonates to cool-water heterozoan carbonates during the Early Permian. Carbonate buildups composed of dominantly thrombolytic micrite with primary biotic components including bryozoan, echinoderm, Tubiphytes, brachiopod and sponge spicules occur as a series of mud mounds restricted to paleobathymetric lows located on present day Ellesmere Island. As many as 43 carbonate mud mounds have been catalogued from both Blind Fiord and Otto Fiord and are described and interpreted using microfacies analysis and geochemical analyses as part of this study. These mounds grew up to 150 m in thickness at the interface between a distally steepened ramp and a sigmoidal slope. This setting was below storm wave base, nutrient rich, and subjected to frequent turbidites and tempestites. Sediments from this environment comprise variably silty heterozoan wackestones and packstones.between a distally steepened ramp and a sigmoidal slope. This setting was below storm wave base, nutrient rich and subjected to frequent turbidites and tempestites. Sediments from this environment comprise variably silty heterozoan wackestones and packstones with primary biotic components including bryozoan, echinoderm, Tubiphytes, brachiopod and sponge spicules.
- ItemOpen AccessMiddle Permian Sedimentology and Sequence Stratigraphy, Sverdrup Basin, Ellesmere Island of the Canadian Arctic(2011) Godek, Gregory; Beauchamp, Benoit
- ItemOpen AccessOrigin of Green Shales in the Devonian Swan Hills Formation, Alberta, Canada(2022-09-19) Howrish, Morgan R.; Beauchamp, Benoit; Meyer, Rodolfo; Ardakani, OmidThroughout its growth history, the Devonian Swan Hills Reef Complex at Swan Hills has been subjected to variably long episodes of subaerial exposure, storm events, strong wind, oceanic currents, base level fluctuations and/or a long post-depositional burial history. For nearly sixty years, several generations of carbonate specialists have invoked one or more of these mechanisms to explain the presence of fine-grained green shale sediment observed sporadically throughout the carbonate-dominated reef complex. Through core examination, petrography and geochemical analysis, this study proposes a new model which reinterprets green shale from the above processes to a coproduct of dolomitizing and potentially non-dolomitizing fluids. The terrigenous clays are suggested to be sourced from underlying clastic formations, in particular, the Watt Mountain Formation, and advected upwards alongside a mixture of carbonate mud, organic matter, pyrite and carbonate debris which accumulated onto the reef environment through hydrothermal mud volcanism. Advection and extrusion of such green shale slurries were associated with NW-SE trending basement faults that initiated buildup nucleation on the widespread platform and acted as an important segment of a large hydrothermal convection cell driven by regional tectonism. In addition to being reducing and toxic, these gaseous slurries were likely episodic in nature, acting in a fault-valve type manner, and resulted in the diverse depositional spectrum of green shale across various facies, diagenetic environments and stratigraphic intervals. The hydrothermal mud volcanism model thus provides a new and testable explanation for the origin, transportation, sedimentation and diagenetic transformations of green shales in the Devonian succession of the Western Canada Sedimentary Basin.
- ItemOpen AccessPaleoecologic Controls on Early Triassic Refugia Distribution(2017) Godbold, Amanda; Henderson, Charles; Beauchamp, Benoit; Dutchak, AlexThe end-Permian extinction (~252 ma) was the largest extinction event to have occurred during the Phanerozoic, resulting in the elimination of up to 78% of marine genera. Recovery from such a catastrophic event did not occur until the Middle Triassic, likely owing to prolonged environmental stress. Many have speculated as to the process with which marine ecosystems recovered following this event. The development of marine refugia, sanctuaries to which organisms migrate during time of environment stress, is one hypothesis. The focus of this thesis is to examine the distribution of marine refugia during the end-Permian extinction. Geochemical and paleoecologic data suggest that mid-depth settings deposited under oxic conditions are conducive to the development of refugia, by offering relief from lethally hot sea surface temperatures. In contrast, geochemical and paleoecologic data collected from two open Panthalassic seamounts suggest that these settings are not conducive to the development of marine refugia, potentially due to decreases in immigration rates owing to the development of a temperature barrier between oceanic islands and the continental margin.
- ItemOpen AccessPennsylvanian–Early Permian Carbonate Shelf to Slope Transition, Sverdrup Basin, Northwest Ellesmere Island, Arctic Canada (Nunavut)(2013-09-25) Shultz, Candice Victoria; Beauchamp, BenoitNear continuous outcrop of Pennsylvanian to Early Permian carbonate strata were studied on northwest Ellesmere Island, in the Sverdrup Basin, Arctic Canada. Six sections were examined displaying shallow water facies of the Nansen Formation and deeper water facies of the Hare Fiord Formation. Petrographic analysis and field observations identified 15 microfacies that represent four main depositional environments along a distally steepened ramp. The environments are: restricted shelf, shoal and patch reef, open shelf, and slope with evidence for exponential slope geometry. This is a new interpretation as the Nansen Formation studied to the north was interpreted as a rimmed shelf with a planar slope geometry. Slope morphology is influenced by: climate change, oceanography and prevailing wind direction, and tectonics.
- ItemOpen AccessPennsylvanian–Permian Aragonite to Calcite Sea Transitions in the Sverdrup Basin (Arctic Canada) and Cantabrian Basin (northern Spain)(2021-07-05) Fernandes, Nikita Judith; Beauchamp, Benoit; Dutchak, Alex; Dewing, KeithDetailed facies analysis of Carboniferous–Permian strata in the Sverdrup Basin (Arctic Canada) and Cantabrian Basin (northern Spain) has led to the recognition of short-lived calcite seas within a first-order aragonite sea. The first return to calcitic conditions is documented in Lower Pennsylvanian carbonate rocks and lasted approximately 4–6 Myrs based on the replacement of aragonitic algae and tangential ooids by calcitic algae and radial ooids in shallow water facies. A second return to calcite sea immediately after the Carboniferous–Permian boundary is documented within an individual cyclothem, ~400,000 years in duration, through a similar shift to calcitic biotic and abiotic elements. These findings indicate higher-order calcite-aragonite episodes may occur during first-order oscillations and are likely influenced by a variety of mechanisms such as magnesium to calcium ratio (Mg:Ca), pCO2, temperature, and carbonate saturation among others. In this study, both the Early Pennsylvanian and Early Permian returns to calcite seas are attributed to increases in atmospheric CO2 due to contemporaneous volcanic activity. As a result, excess CO2 was buffered through the shoaling of saturation horizons in the ocean resulting in the non-precipitation and/or dissolution of the more soluble mineral phases such as aragonite and high-Mg calcite. A very shallow aragonitic zone is inferred in the Sverdrup Basin compared to a slightly deeper interval in the Cantabrian Basin, which is due to the higher paleolatitude of the Sverdrup Basin. Shoaling of aragonite and HMC saturation horizons is currently occurring in modern oceans due to the increased uptake of CO2 accelerating the rate of ocean acidification. Therefore, one of the long-term consequences of continued increases in anthropogenic CO2 could be the establishment of oceanic conditions like those of a calcite sea.
- ItemOpen AccessPermian tectonism in the Sverdrup Basin, Axel Heiberg Island, Arctic Canada(2018-07-17) Alonso Torres, Daniel; Beauchamp, Benoit; Henderson, Charles Murray; Hubbard, Stephen M.The Mississippian to Eocene Sverdrup Basin in the Canadian Arctic has long been considered to have originated as a rift following the collapse of the Devonian to Mississippian Ellesmerian Orogen. From latest Pennsylvanian to Middle Permian time, several tectonic events were accompanied by outpouring of volcanic material and the addition of a northern sediment source, presently lying beneath the Arctic Ocean. This thesis encompasses geochronological, stratigraphic and structural analyses with a focus on Pennsylvanian to Lower Triassic strata and deformational events on the northern portion of the Sverdrup Basin. Northerly-sourced sediments contain a syndepositional zircon sub-population, deposited in an area that experienced multiple Pennsylvanian to Triassic uplift and deformation pulses, providing evidence for the existence of a magmatically and tectonically active margin to the north. In contrast to the passive margin setting traditionally assumed for northern Laurentia, these results require a reevaluation of the Sverdrup Basin as a backarc to retroarc basin.
- ItemOpen AccessQuantitative Trilobite Biostratigraphy of the Middle Cambrian (Wuliuan Stage; Miaolingian Series) and Microfacies Analysis of the Middle Cambrian Stephen Formation, Southern Canadian Rocky Mountains(2021-07-06) Morgan, Chad Alexander; Henderson, Charles Murray; Beauchamp, Benoit; Hubbard, Stephen; Dewing, Keith; Webster, MarkCarbonate microfacies and trilobite successions were examined in seven sections of the Stephen Formation, southern Canadian Rocky Mountains. Seven microfacies and three ichnofacies are identified, including a new Protopaleodictyon ichnofacies with Protopaleodictyon aitkeni (n. isp.). Palaeoenvironments include ephemeral oolitic shoals, intraclastic/oncoidal tempestites, and quiescent muddy-bottomed mid-shelf within a low-latitude, carbonate platform. Three parasequences were identified in the Narao Member, and five in the Waputik Member. Narao Member parasequences are sub-tidal muddy carbonate, shallowing toward microbial build-ups. Waputik Member parasequences contain green-grey, laminated shale, with sporadic carbonate tempestites, indicating a platform inundated by upwelling cool-dysoxic water. Carbonate production was shut-off, except within localized shoals and build-ups. The stacking pattern indicates slow base-level change with periodic upwelling events. The overlying Eldon Formation re-established carbonate platform deposition associated with a stabilised chemocline. Chemocline perturbation is postulated to affect trilobite biomere extinction at the Narao-Waputik boundary. Fifteen trilobite species, eleven trilobite genera, one orthothecid, one edrioasteroid, and three Burgess Shale organisms (Tuzoia, Haplophrentis carinatus, Margaretia dorus) were identified in the Stephen Formation, which ranges from the uppermost Glossopleura Assemblage Biozone into the Ehmaniella Assemblage Biozone. Four new biozones are established in this interval, including the Glossopleura boccar, Proehmaniella basilica, Ehmaniella waptaensis, and Spencella montanensis interval biozones. A quantitative biostratigraphy using Unitary Association (UA), integrates regional biozones from southwestern USA and western Canada into a unified Miaolingian trilobite succession (582 taxa, 1035 samples, 121 sections, and 48 formations). Seventy-three UA biozones, including 33 previously defined biozones, are delineated from the upper Bonnia-Olenellus to Cedaria assemblage zones. Six new Wuliuan interval biozones (Fieldaspis superba, Albertella bosworthi, Glossopleura boccar, Proehmaniella basilica, Spencella montanensis, and Bathyuriscus adaeus) are established. Nineteen UA zones encompass the top of the upper Bonnia-Olenellus Assemblage Biozone, 11 in the Plagiura-Poliella Assemblage Biozone, 18 in the Albertella Assemblage Biozone, 10 within the Glossopleura Assemblage Biozone, 7 within the Ehmaniella Assemblage Biozone, and 8 in the Bolaspidella and Cedaria biozones. This is the first recognition of temporal equivalence of regional biozones using quantitative biostratigraphic methods. The faunal succession informs biostratigraphic correlation potential pointing to mid-Cambrian intervals that may yield additional high-resolution biozones in the future.
- ItemOpen AccessSea Ice Melt Onset Dynamics in the Northern Canadian Arctic Archipelago from RADARSAT, 1997-2014(2016-01-08) Mahmud, Mallik Sezan; Yackel, John; Beauchamp, Benoit; Howell, Stephen; Hall-Beyer, MrykaAn algorithm was developed to detect melt onset over Arctic sea ice using high-resolution SAR images from RADARSAT. The algorithm is based on the temporal evolution of the SAR backscatter coefficient (σ⁰), using an ice type specific threshold approach that also corrects for backscatter incidence angle variation. Using 4457 RADARSAT images, the algorithm was applied over sea ice in the northern CAA, thus generating a new time series of melt onset from 1997-2014. The mean annual melt onset date was on YD 164±4 (mid–June). No significant trend was found over the 18-year period, however, variability increased in post-2007 years. An earlier (later) melt onset was associated with increased (decreased) solar energy absorption and subsequently associated in lighter (heavier) September sea ice coverage in the northern CAA. RADARSAT estimates of melt onset were found to be in good agreement but more robust compared to passive microwave and scatterometer estimates.
- ItemOpen AccessSequence Stratigraphy, Conodont Biostratigraphy and Sedimentology of Lower Permian Strata of the Fosheim–Hamilton Sub–basin, Sverdrup Basin, Ellesmere Island, Canadian Arctic(2009) Wamsteeker, Michael L.; Beauchamp, Benoit; Henderson, Charles M.
- ItemOpen AccessStratigraphy and facies analysis of the upper carboniferous to lower permian canyon fiord, Belcher Channel and Hansen Formations, southwestern Ellesmere Island(1987) Beauchamp, Benoit; Oldershaw, Alan E.
- ItemOpen AccessStratigraphy and Geochemistry of Lower Permian volcanics in the Sverdrup Basin, Northwest Ellesmere Island, Nunavut(2013-06-17) Morris, Natasha; Beauchamp, Benoit; Cuthbertson, JenniferFive sections of Lower Permian mafic volcanics were examined on northwest Ellesmere Island in the Sverdrup Basin, Arctic Canada. Detailed field work shows that two stratigraphic levels exist; the lower level is an unnamed volcanic unit that occurs in a Sakmarian-Artinskian succession, and the upper level is a mappable unit, the Esayoo Formation, which occurs in a Kungurian succession. Within the regional upper Paleozoic sequence stratigraphy the volcanics are contemporaneous with transgressive systems tracts. Petrographically, these volcanics are spilites. Trace element chemistry illustrates patterns similar to ocean island basalts. Tectonic discriminant diagrams show affinities to within plate basalts, with alkaline to transitional basalt affinities. Sm-Nd isotopic analyses suggest the Esayoo Formation is sourced from an enriched mantle, with values that range from -3.99 to -5.87. Trace element ratios reveal an enriched mantle type I (EMI) source. In addition these volcanic occurences are synchronous with coeval compressional-extensional tectonic pulses associated with the Melvillian Disturbance.