Geology Reports⌕ Search

SEARCH · Geology Reports

Results for “Arctic”

Search indexed USGS publications on groundwater, aquifers, geologic maps, mineral resources and earthquakes. Explore source records by subject and place.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 577 records · Page 32Linked to original sources
USGS2018

A comparison of photograph-interpreted and IfSAR-derived maps of polar bear denning habitat for the 1002 Area of the Arctic National Wildlife Refuge, Alaska

Polar bears ( Ursus maritimus ) in Alaska use the Arctic National Wildlife Refuge (ANWR) for maternal denning. Pregnant bears den in snow banks for more than 3 months in winter during which they give birth to and nurture young. Denning is one of the most vulnerable times in polar bear life history as the family group cannot simply walk away from a disturbance without jeopardizing survival of newly born cubs. The ANWR includes the “1002 Area”, a region recently opened for oil and gas exploration by the U.S. Department of the Interior (DOI). As a part of its mission, the DOI “… protects and manages the Nation's natural resources …” and is therefore responsible for conserving polar bears and encouraging development of energy potential. Because future industrial activities could overlap habitats used by denning polar bears, identifying these habitats can inform the decisions of resource managers tasked to develop resources and protect polar bears. To help inform these efforts, we qualitatively compared the distribution of denning habitat identified by two different methods: previously published habitat from manual interpretation of aerial photographs, and habitat derived by computer interrogation of interferometric synthetic aperture radar (IfSAR) digital terrain models (DTM). Because photograph-interpreted methods depicted denning habitat as a line and IfSAR-derived methods depicted habitat as a polygon, we assessed agreement between the two methods with distance measurements. We found that 77.5 percent of IfSAR-derived denning habitat (79.6 km2 ; 1.2 percent of the 6,837.0 km2 1002 Area) was within 600 m of photograph-interpreted habitat (3,026.9 km), including 53.9 percent within 200 m. This distribution differed from that of randomly distributed points, as only 49.4 percent of these occurred within 600 m of photograph-interpreted habitat, including 18.3 percent within 200 m. Both methods appear to identify the major physiographic features that polar bears might select for denning. IfSAR-derived methods identified habitat at greater frequency beyond major landscape features such as coastal bluffs, river banks and lakeshores, were more likely to identify isolated pockets of putative denning habitat, and were easier to implement than deriving habitat from photograph-interpretive efforts. However, previous research suggests that photograph-interpretation methods may identify denning habitat more correctly than computer interrogation of IfSAR DTMs. Future work should quantify the distribution of IfSAR-derived denning habitat relative to actual landscape features and polar bear maternal dens in the 1002 Area, and investigate the feasibility of habitat identification from finer grained DTMs.

Alaska↗
USGS2020

Sample-size considerations for a study of shorebird nest survival in the 1002 Area, Arctic National Wildlife Refuge, Alaska

Authorization of lease sales for oil development in the 1002 Area of the Arctic National Wildlife Refuge has highlighted gaps in information about biological communities in the area. The U.S. Fish and Wildlife Service, which is planning a study to evaluate spatial variation in the nest survival of tundra-breeding shorebirds to identify hotspots with high nest survival, sought advice from the U.S. Geological Survey on how to predict which sampling designs might be successful in achieving the study goals. I used previously obtained data on nest survival from Alaska’s North Slope to develop a simulation study that explored the statistical consequences of various sampling designs in the context of expected ranges of values of biological parameters. Of all sampling parameters, the number of nests per plot had the strongest influence on the ability to detect hotspots, followed by number of years of monitoring and the age at which nests were found. The benefit of sampling 98 plots instead of 68 was relatively small. Ages of nests cannot be predicted a priori, so I developed a field reference chart to identify when further nest-searching would be useful for a given plot. This simulation study used the best available information, but values of biological parameters will become better defined following subsequent data collection in the 1002 Area. Data from upcoming field seasons could be used to refine this analysis and improve estimation of the expected results of the field study, thus maximizing the likelihood that data from the 1002 Area nest survival study will meet the monitoring goals.

Alaska↗
USGS1976

The Lisburne Group: A potential major hydrocarbon objective of the Arctic Slope, Alaska

The Lisburne Group, a thick carbonate rock unit of Mississippian and Pennsylvanian age, is one of the most widespread potential reservoir rock units in northern Alaska. A comprehensive review of the Lisburne in the subsurface of the eastern Arctic Slope indicates attractive reservoir characteristics in a favorable source and migration setting where numerous trapping mechanisms appear to be available. Evaluation of this group as a potential exploration objective is particularly timely in view of impending offshore sales in the Beaufort Sea and current exploration programs underway in the Prudhoe Bay area and the Naval Petroleum Reserve. Dolomite and sandstone have been identified as reservoir rocks. Oolitic grainstone is a common rock type, but all observations to date indicate little reservoir potential owing to complete void filling by calcite cement. The most important reservoir rock as judged by thickness, areal extent, and predictability is microsucrosic (10-30 μ) dolomite of intertidal to supratidal origin. It is present throughout the Lisburne and is most abundant near the middle of the sequence. Northward it decreases in thickness from 1,000 feet (300 m) to less than 100 feet (30 m). Porosity of the dolomite as determined in selected wells averages between 10 and 15 percent and attains a maximum of slightly more than 25 percent. Net thickness of reservoir rocks (i.e., rocks with greater than 5 percent porosity) varies in these wells from 140 feet (40 m) to 390 feet (120 m). Oil shows are common, and drill-stem tests have yielded as much as 1,600 bbls/day oil and 22 MMcf/day gas in the Lisburne pool of the Prudhoe Bay Field and as much as 2,057 bbls/day saltwater outside the field area. The occurrence of dolomite over such a large area makes its presence in the offshore Beaufort Sea and adjacent Naval Petroleum Reserve No. 4 fairly certain. The occurrence of sandstone as thick as 140 feet (40 m) in the middle and upper part of the Lisburne in two coastal wells suggests that larger areas of sandstone may be found to the north in offshore areas. Shows of oil and gas and a saltwater flow of 1,470 bbls/day have been recorded from this sandstone facies. Shales of Permian and Cretaceous age unconformably overlie the Lisburne, providing adequate sealing beds above potential reservoirs. Impermeable limestone (completely cemented grainstone) and thin beds of shale may serve as seals within the Lisburne, but the possibility of fractures in these units may negate their sealing capability. The most favorable source rock for Lisburne hydrocarbons appears to be Cretaceous shale that unconformably overlies the Lisburne east of Prudhoe Bay. This shale is reported by Morgridge and Smith (1972) to be a rich source rock and is the most likely source for the entire Prudhoe Bay Field. A source within the Lisburne or within the underlying Kayak Shale is postulated to explain oil shows in the southernmost Lisburne wells. This postulated source may be in a more basinal facies of the Lisburne and may be similar to dark shale in the upper Lisburne found in thrust slides in the Brooks-Range. Coal in the underlying Endicott Group is a possible source for dry gas. It is inferred that at the present time much of this coal is in a gas—generating regime downdip from the Prudhoe Bay Field area. Stratigraphic traps involving the Lisburne Group may exist as a result of widespread Permian and Cretaceous unconformities. Structural traps related to normal faulting may occur along the trend of the Barrow Arch, and faulted anticlines are numerous in the foothills of the Brooks Range. Combination traps are possible along the trend of the Barrow Arch at places where both stratigraphic and structural trap might exist.

Alaska↗
USGS1982

Depth and temperature of permafrost on the Alaskan Arctic Slope; preliminary results

As permafrost is defined by its temperature, the only way to determine its depth is to monitor the return to equilibrium of temperatures in boreholes that penetrate permafrost. Such measurements are under way in 25 wells on the Alaskan Arctic Slope; 21 are in Naval Petroleum Reserve Alaska (NPRA), and 4 are in the foothills to the east. Near-equilibrium results indicate that permafrost thickness in NPRA generally ranges between 200 and 400 m (compared to 600+ m at Prudhoe Bay); there are large local variations and no conspicuous regional trends. By contrast the long-term mean temperature of the ground surface (one factor determining permafrost depth) varies systematically from north to south in a pattern modified by the regional topography. The observed variation in permafrost temperature and depth cannot result primarily from effects of surface bodies of water or regional variations in heat flow; they are consistent, however, with expectable variations in the thermal conductivity of the sediments. It remains to be determined (with conductivity measurements) whether certain sites with anomalously high local gradients have anomalously high heat flow; if they do, they might indicate upwelling of interstitial fluids in the underlying basin sediments.

Open-File Report↗
USGS1991

Planktic foraminifer census data from Northwind Ridge Core 5, Arctic Ocean

The U.S. Geological Survey recovered 9 piston cores from the Northwind Ridge in the Canada Basin of the Arctic Ocean from a cruise of the USCGC Polar Star during 1988. Preliminary analysis of the cores suggests sediments deposited on Northwind Ridge preserve a detailed record of glacial and interglacial cycles for the last few hundred-thousand to one million years. This report includes quantitative data on foraminifers and selected sediment size-fraction data in samples from Northwind Ridge core PI-88AR P5.

Open-File Report↗
USGS1995

Arctic delta processes: A computer animation and paper models

This report shows, by means of a computer animation and paper models, how deltas are affected by fresh and salt water currents, topography and location. The report is intended to help students and others visualize how ice shapes and forms a delta. By studying the animations and the paper models, students will come to understand why deltas have different shapes and different interior structures. The diskette version has an animation of arctic delta processes. While both the diskette and paper versions have teacher guide and paper models.

Open-File Report↗
USGS1999

The Timan-Pechora Basin province of northwest Arctic Russia; Domanik, Paleozoic total petroleum system

The Domanik-Paleozoic oil-prone total petroleum system covers most of the Timan-Pechora Basin Province of northwestern Arctic Russia. It contains nearly 20 BBOE ultimate recoverable reserves (66% oil). West of the province is the early Precambrian Eastern European craton margin. The province itself was the site of periodic Paleozoic tectonic events, culminating with the Hercynian Uralian orogeny along its eastern border. The stratigraphic record is dominated by Paleozoic platform and shelf-edge carbonates succeeded by Upper Permian to Triassic molasse siliciclastics that are locally present in depressions. Upper Devonian (Frasnian), deep marine shale and limestone source rocks ? with typically 5 wt % total organic carbon ? by middle Mesozoic time had generated hydrocarbons that migrated into reservoirs ranging in age from Ordovician to Triassic but most focused in Devonian and Permian rocks. Carboniferous structural inversions of old aulacogen borders, and Hercynian (Permian) to Early Cimmerian (Late Triassic to Early Jurassic) orogenic compression not only impacted depositional patterns, but also created and subsequently modified numerous structural traps within the province.

Open-File Report↗
USGS1999

South and North Barents Triassic-Jurassic total petroleum system of the Russian offshore Arctic

One major gas-prone petroleum system characterizes the sparsely explored South and North Barents Basin Provinces of the Russian Arctic in the eastern Barents Sea. More than 13 billion barrels of oil equivalent (79 trillion cubic feet of gas) known ultimately recoverable gas reserves in seven fields were sourced from Triassic marine and continental shales and stored in Jurassic (97%) and Triassic (3%) marine and continental sandstone reservoir rocks. The basins contain 18-20 kilometers of pre-Upper Permian carbonate and post-Upper Permian siliciclastic sedimentary fill. Late Permian-Triassic(?) rifting and subsidence resulted in the deposition of as much as 9 kilometers of Triassic strata, locally injected with sills. Rapidly buried Lower Triassic source rocks generated hydrocarbons as early as Late Triassic into stratigraphic traps and structural closures that were modified periodically. Thermal cooling and deformation associated with Cenozoic uplift impacted seal integrity and generation processes, modified traps, and caused gas expansion and remigration.

Open-File Report↗
USGS1920

Pliocene and Pleistocene fossils from the Arctic coast of Alaska and the auriferous beaches of Nome, Norton Sound, Alaska

Exploration of the geology of the Arctic and subarctic shores of Alaska began as early as the voyages of Kotzebue and Beechey, in 1816 and 1826, and a detailed report on the vertebrate fossils found there, with a wealth of illustration, was made by Sir John Richardson in 1854, in the "Zoology of the voyage of the Herald." Nothing of importance beating on the Tertiary invertebrates of this region appears in the literature of the nineteenth century, and but little on those of the older formations.

Alaska↗
USGS2019

Geology and assessment of undiscovered oil and gas resources of the Arctic Alaska Province, 2008

The Arctic Alaska Province encompasses all lands and adjacent continental shelf areas north of the Brooks Range-Herald Arch tectonic belts and south of the northern (outboard) margin of the Alaska rift shoulder. Even though only a small part is thoroughly explored, it is one of the most prolific petroleum provinces in North America, with total known resources (cumulative production plus proved reserves) of about 28 billion barrels of oil equivalent. For assessment purposes, the province is divided into a platform assessment unit, comprising the Alaska rift shoulder and its relatively undeformed flanks, and a fold-and-thrust belt assessment unit, comprising the deformed area north of the Brooks Range and Herald Arch tectonic belts. Mean estimates of undiscovered, technically recoverable resources include nearly 28 billion barrels of oil and 122 trillion cubic feet of nonassociated gas in the platform assessment unit and 2 billion barrels of oil and 59 trillion cubic feet of nonassociated gas in the fold-and-thrust belt assessment unit.

Alaska, Yukon↗
USGS2020

Geology and assessment of undiscovered oil and gas resources of the Franklinian Shelf Province, Arctic Canada and North Greenland, 2008

In 2008, the U.S. Geological Survey assessed the potential for undiscovered oil and gas resources of the Franklinian Shelf Province of northern Canada and Greenland as part of the U.S. Geological Survey Circum-Arctic Resource Appraisal Program. The Franklinian Shelf Province lies along the northernmost edge of the North American craton in Greenland and Canada. It encompasses a Cambrian through Middle Devonian passive margin sequence deposited on the margin of an ocean formed by rifting and seafloor spreading that began in latest Precambrian time and continued into Ordovician time. In the Canadian part of the province, the passive margin sequence is overlain by a thick succession of Devonian clastic strata shed from uplifts produced by the Caledonian collision between Laurentia and Baltica that closed Iapetus Ocean. The late Silurian to Early Devonian Boothia-Cornwallis uplifts within the region, apparently a distal effect of earlier phases of the Caledonian collision, were local sources of clastic wedges within the predominantly carbonate shelf sequence. Much of the northern part of the province was subjected to folding and thrusting during Late Devonian to earliest Carboniferous Ellesmerian deformation, followed by a prolonged period of erosion. The eastern part of the province again experienced transpressive and compressive deformation as Greenland converged with North America during the early Tertiary Eurekan orogeny. Potential source rocks include Ordovician to Lower Devonian shales that contain abundant oil-prone organic matter, deposited on the outer continental shelf and slope. The most likely source rocks are Silurian strata, deposited as the continental shelf was drowned by a marine transgression caused by regional subsidence most likely associated with thrust loading. Potential source rocks in Greenland also may include organic-rich Cambrian shales deposited on the continental shelf. Rapid burial by thick Caledonian-derived strata in Late Devonian time abruptly matured the source rocks and generated oil; continued rapid burial may have cracked much of the accumulated oil to gas. In North Greenland, oil generation may have resulted from burial by now-eroded Devonian strata or from burial by Ellesmerian thrust sheets. Widespread bitumen in outcrops and in exploration wells appears to confirm that oil was indeed generated. Potential reservoirs include Cambrian nearshore clastic strata, Cambrian to Silurian carbonate bank strata, and Silurian to Middle Devonian reef buildups on the drowned shelf. Because Ellesmerian deformation postdated migration, only stratigraphic traps are likely, except in the area of the Boothia-Cornwallis uplift, a north-trending, structurally elevated zone, where structural traps formed by late Silurian to Early Devonian deformation are possible. It is unlikely that any large accumulations survived subsequent deformation or uplift and erosion. Three assessment units were defined: the Western Franklinian Shelf, the Boothia-Cornwallis Uplift, and the Eastern Franklinian Shelf Assessment Units. These assessment units were not quantitatively assessed, mostly because of the high risk to timing and preservation.

Franklinian Shelf Province↗
USGS2020

Geology and assessment of undiscovered oil and gas resources of the Sverdrup Basin Province, Arctic Canada, 2008

The Sverdrup Basin Province, an area of 515,000 square kilometers on the northern margin of North America, extends 1,300 kilometers across the Canadian Arctic Islands from near the Mackenzie Delta to northern Ellesmere Island. It consists of an intracratonic late Paleozoic to early Cenozoic rift-sag basin and a Mesozoic rift shoulder that bounds it on the north. Basin inception was Mississippian, manifested by deposition of nonmarine strata in rift basins, followed by Pennyslvanian marine transgression, which began with evaporites and progressed to Permian carbonate and clastic deposition at basin fringes and organic-rich marine strata in the basin center. Sediment transport was both northward from North America and southward from a now-subsided or rifted-away landmass to the north. Mesozoic strata indicate continued marine deposition, including both organic-rich, fine-grained rocks deposited during highstands and progradational deltaic sequences. A new episode of rifting began in Middle Jurassic time and culminated in the opening of the Canada Basin by Early Cretaceous seafloor spreading. The Sverdrup Rim formed as the rift shoulder between North America and the thinned, subsided crust to the north. Widespread Upper Cretaceous organic-rich shales were deposited during the major transgression induced by Canada Basin opening, followed by an influx of coarser east-derived detritus. In Paleogene time, incipient North Atlantic seafloor spreading caused deformation in northeasternmost North America, producing uplifts that shed detritus westward across the Sverdrup Basin. Tight folding and thrusting resulting from the Eurekan orogeny took place in the eastern part of the basin during the Eocene, with decreasing intensity of deformation westward. Since deformation ended in late Eocene time, little significant tectonism or deposition has taken place. Two petroleum systems were defined in the Sverdrup Basin Province. Upper Paleozoic marine shale generated petroleum beginning in the Early Triassic, but this petroleum system was not quantitatively assessed because reservoir quality in adjacent strata is poor, the rocks are mostly overmature, and subsequent deformation likely affected trap integrity. The second petroleum system was sourced by Lower Triassic strata rich in oil-prone organic matter. Oil was generated during Paleogene burial synchronous with Eurekan deformation, and the oil migrated into Triassic and Jurassic deltaic, shallow marine and nonmarine strata. However, most of the oil may have escaped during deformation and subsequent uplift and erosion, which probably caused oil to be displaced from traps by gas expansion. The population of undiscovered accumulations was characterized as likely to include stratigraphically trapped and small, structurally trapped accumulations, with a median size of 80 million barrels of oil (MMBO); the number of undiscovered accumulations was estimated to be between 1 and 50, with the most likely number being 10. The resulting estimate of undiscovered, technically recoverable, conventional oil resources is 61 to 1,255 MMBO, with a mean of 427 MMBO. Undiscovered, technically recoverable, conventional gas resources are estimated at 4.95 trillion cubic feet (TCF), with slightly more than half of that in nonassociated gas accumulations. A third petroleum system in the adjacent Amerasia Basin Province to the north was considered somewhat likely to contain accumulations on the Sverdrup Rim. Deeply buried Upper Jurassic, Upper Cretaceous, and Eocene organic-rich strata probably generated oil that may have migrated up the continental slope into Triassic to Paleogene sandstones on the Sverdrup Rim. Based on analogy with the Barrow Arch in Alaska, a median of 20 accumulations was estimated, with accumulation volumes as much as 2,500 MMBO and a median of 100 MMBO. The probability of at least one accumulation of the minimum size assessed (50 MMBO) was estimated at 0.22. The resulting estimate of undiscovered, technically recoverable, conventional oil resources is 0 to 2,679 MMBO, with a mean of 424 MMBO. Mean estimates for associated and nonassociated gas are 1.3 and 2.3 TCF, respectively.

Sverdrup Basin↗
USGS2012

Assessment of undiscovered petroleum resources of the Arctic Alaska Petroleum Province

The Arctic Alaska Petroleum Province encompasses all lands and adjacent continental shelf areas north of the Brooks Range-Herald arch tectonic belts and south of the northern (outboard) margin of the Alaska rift shoulder. Even though only a small part is thoroughly explored, it is one of the most prolific petroleum provinces in North America, with total known resources (cumulative production plus proved reserves) of about 28 billion barrels of oil equivalent. For assessment purposes, the province is divided into a platform assessment unit, comprising the Alaska rift shoulder and its relatively undeformed flanks, and a fold-and-thrust belt assessment unit, comprising the deformed area north of the Brooks Range and Herald arch tectonic belts. Mean estimates of undiscovered, technically recoverable resources include nearly 28 billion barrels of oil and 122 trillion cubic feet of nonassociated gas in the platform assessment unit and 2 billion barrels of oil and 59 trillion cubic feet of nonassociated gas in the fold-and-thrust belt assessment unit.

Alaska↗
USGS2016

Alaska Arctic marine fish ecology catalog

The marine fishes in waters of the United States north of the Bering Strait have received new and increased scientific attention over the past decade (2005–15) in conjunction with frontier qualities of the region and societal concerns about the effects of Arctic climate change. Commercial fisheries are negligible in the Chukchi and Beaufort Seas, but many marine species have important traditional and cultural values to Alaska Native residents. Although baseline conditions are rapidly changing, effective decisions about research and monitoring investments must be based on reliable information and plausible future scenarios. For the first time, this synthesis presents a comprehensive evaluation of the marine fish fauna from both seas in a single reference. Although many unknowns and uncertainties remain in the scientific understanding, information presented here is foundational with respect to understanding marine ecosystems and addressing dual missions of the U.S. Department of the Interior for energy development and resource conservation.

Scientific Investigations Report↗
USGS2001

Hydrologic data and a proposed water-quality monitoring network for the Kobuk River basin, Gates of the Arctic National Park and Preserve, and Kobuk Valley National Park, Alaska

Located in northwestern Alaska, the Kobuk River drains a watershed of approximately 12,300 square miles. Two national parks are located in the basin: the entire Kobuk Valley National Park and and a portion of Gates of the Arctic National Park and Preserve. Reconnaissance-type water-quality data collected on the Kobuk River and some of its tributaries indicate that the water is of a calcium to calcium-magnesium-bicarbonate type. To design a representative water-quality monitoring network, a geographical information system (GIS) of the Kobuk River Basin was created. The GIS was used with a statistical technique, cluster analysis, to stratify the Kobuk River Basin into different regions. Potential water-quality monitoring sites were then selected from these regions.

Alaska↗
USGS2017

Basal debris entrainment and transport in glaciers of southwestern Bylot Island, Canadian Arctic

Glaciers on southwestern Bylot Island in the Canadian Arctic flow from an alpine setting in high-grade crystalline Archean terrane, on to coastal lowlands underlain by clastic sedimentary strata of Cretaceous to Tertiary age. We have used the contrasting mineralogy of the substrate as a tool to study subglacial entrainment and transport of debris in two large piedmont glaciers on Bylot Island. High chlorite/ and mica-illite/smectite ratios indicate that most basal debris is derived from crystalline rocks underlying the upper reaches of the glaciers. The subglacial accretion of Cretaceous-Tertiary sediments appears restricted to the lowermost part of the basal zone and is most noticeable near the glaciers' termini. Ice associated with discrete silty-sandy debris layers is characterized by an isotopic signature indicative of refreezing of meltwater at the glacier sole. The compositional, textural and isotopic characteristics of basal sediment and ice lead us to conclude that subglacial entrainment through basal ice accretion occurs in both the upper and marginal parts of the glaciers.

Bylot Island↗
USGS2023

Unrecorded tundra fires of the Arctic Slope, Alaska USA

Few fires are known to have burned the tundra of the Arctic Slope north of the Brooks Range in Alaska, USA. A total of 90 fires between 1969 and 2022 are known. Because fire has been rare, old burns can be detected by the traces of thermokarst and distinct vegetation they leave in otherwise uniform tundra, which are visible in aerial photograph archives. Several prehistoric tundra burns have been found in this way. Detection of tundra fires in this sparsely populated and remote area has been historically inconsistent and opportunistic, relying on reports by aircraft pilots. Fire reports have been logged into an administrative database which, out of necessity, has been used to scientifically evaluate changes in the fire regime. To improve the consistency of the record, we completed a systematic search of Landsat Collection 2 for the Brooks Range Foothills ecoregion over the period 1972–2022. We found 57 unrecorded tundra burns, about 41% of the total, which now numbers 138. Only 15% and 33% of all fires appear in MODIS and VIIRS satellite-borne thermal anomaly products, respectively. The fire frequency in the first 37 years of the record is 0.89 y −1 for natural ignitions that spread ≥10 ha. Frequency in the last 13 years is 2.5 y −1 , indicating a nearly three-fold increase in fire frequency.

Alaska↗
USGS2019

Unravelling the tectonics of Pearya Terrane, Nunavut: GEM-2 Western Arctic Project, report of activities 2018

GSC scientists were part of an international team of researchers who visited bedrock outcrops on northernmost Ellesmere Island in the summer of 2017. The purpose of the expedition was to document and sample the rocks of Pearya terrane and study the tectonic history of the terrane in order to better reconstruct the past stages of continental drift that formed the Arctic Ocean.

Nunavut↗