Biostratigraphy, Age, and Paleoenvironment of the Pliocene Beaufort Formation on Meighen Island, Canadian Arctic Archipelago

2021 ◽  
Keyword(s):  
Sea Level ◽  
Marine Sediments ◽  
Canadian Arctic ◽  
Atmospheric Co2 ◽  
Paleomagnetic Data ◽  
Canadian Arctic Archipelago ◽  
Warm Climate ◽  
Western Side ◽  
Continuous Deposition

The Beaufort Formation records extraordinary details of Arctic environments and amplified temperatures at approximately modern levels of atmospheric CO2. It was deposited during the Neogene on the western side of what is now the Canadian Arctic Archipelago. Meighen Island is a key locality for studying this formation because marine sediments there are interbedded with terrestrial fossiliferous sands. The biostratigraphic succession, fossils from the marine beds, and paleomagnetic data from the Bjaere Bay region of the island suggest two potential ages for the studied exposures: either continuous deposition at ca. 3.0 Ma, or a sequence of deposits at ca. 4.5 Ma and 3.4 Ma. The sediments appear to encompass at least two eustatic highstands of sea level and a particularly warm climate interval of the Pliocene Arctic.

scholarly journals Biostratigraphy, Age, and Paleoenvironment of the Pliocene Beaufort Formation on Meighen Island, Canadian Arctic Archipelago

2021 ◽  
Author(s):  
R.W. Barendregt ◽  
J.V. Matthews ◽  
V. Behan-Pelletier ◽  
J. Brigham-Grette ◽  
J.G. Fyles ◽  
...  
Keyword(s):  
Sea Level ◽  
Marine Sediments ◽  
Canadian Arctic ◽  
The Arctic ◽  
Canadian Arctic Archipelago ◽  
Organic Debris ◽  
Late Neogene ◽  
Key Factor ◽  
Stratigraphic Succession ◽  
Sequence Unit

ABSTRACT Meighen Island, in the Canadian Arctic Archipelago, is one of the most important localities for study of the late Neogene Beaufort Formation because of the presence of marine sediments interbedded with terrestrial fossiliferous sands. The stratigraphic succession, fossils from the marine beds, correlation with reconstructions of sea level, and paleomagnetic data from the Bjaere Bay region of the island suggest that the Beaufort Formation on Meighen Island was likely deposited either at 3.2–2.9 Ma or during two intervals at ca. 4.5 Ma and 3.4 Ma. The exposed Beaufort Formation on Meighen Island probably encompasses at least one warm interval and eustatic sea-level highstand of the Pliocene. Fossils of plants and arthropods are abundant in the alluvial sands exposed in the Bjaere Bay region. The lower part of the sequence (Unit A), beneath the muddy marine sequence (Unit B), contains plant taxa that have not been seen above the marine beds. Sediments below the marine beds are dominated more by fossils of trees, whereas the organic debris from above marine beds contains many fossils of plants, insects, and mites characteristic of open treeless sites. Regional tree line probably occurred on Meighen Island during deposition of the upper sediments, which implies a mean July climate at least 9 °C warmer than at present. When the marine sediments were deposited, nearshore water temperatures probably did not fall below 0 °C; hence, the Arctic Ocean probably lacked perennial ice cover. This confirms recent modeling experiments exploring the causes of Arctic amplification of temperature that have found the removal of sea ice to be a key factor in resolving previous proxy-model mismatches.

scholarly journals Regional variability of acidification in the Arctic: a sea of contrasts

2014 ◽  
Vol 11 (2) ◽  
pp. 293-308 ◽  
Author(s):  
E. E. Popova ◽  
A. Yool ◽  
Y. Aksenov ◽  
A. C. Coward ◽  
T. R. Anderson
Keyword(s):  
Climate Change ◽  
Primary Production ◽  
Arctic Ocean ◽  
Canadian Arctic ◽  
Atmospheric Co2 ◽  
The Arctic ◽  
Canadian Arctic Archipelago ◽  
Regional Variability ◽  
The Arctic Ocean ◽  
The Impact

Abstract. The Arctic Ocean is a region that is particularly vulnerable to the impact of ocean acidification driven by rising atmospheric CO2, with potentially negative consequences for calcifying organisms such as coccolithophorids and foraminiferans. In this study, we use an ocean-only general circulation model, with embedded biogeochemistry and a comprehensive description of the ocean carbon cycle, to study the response of pH and saturation states of calcite and aragonite to rising atmospheric pCO2 and changing climate in the Arctic Ocean. Particular attention is paid to the strong regional variability within the Arctic, and, for comparison, simulation results are contrasted with those for the global ocean. Simulations were run to year 2099 using the RCP8.5 (an Intergovernmental Panel on Climate Change (IPCC) Fifth Assessment Report (AR5) scenario with the highest concentrations of atmospheric CO2). The separate impacts of the direct increase in atmospheric CO2 and indirect effects via impact of climate change (changing temperature, stratification, primary production and freshwater fluxes) were examined by undertaking two simulations, one with the full system and the other in which atmospheric CO2 was prevented from increasing beyond its preindustrial level (year 1860). Results indicate that the impact of climate change, and spatial heterogeneity thereof, plays a strong role in the declines in pH and carbonate saturation (Ω) seen in the Arctic. The central Arctic, Canadian Arctic Archipelago and Baffin Bay show greatest rates of acidification and Ω decline as a result of melting sea ice. In contrast, areas affected by Atlantic inflow including the Greenland Sea and outer shelves of the Barents, Kara and Laptev seas, had minimal decreases in pH and Ω because diminishing ice cover led to greater vertical mixing and primary production. As a consequence, the projected onset of undersaturation in respect to aragonite is highly variable regionally within the Arctic, occurring during the decade of 2000–2010 in the Siberian shelves and Canadian Arctic Archipelago, but as late as the 2080s in the Barents and Norwegian seas. We conclude that, for future projections of acidification and carbonate saturation state in the Arctic, regional variability is significant and needs to be adequately resolved, with particular emphasis on reliable projections of the rates of retreat of the sea ice, which are a major source of uncertainty.

Geomorphic diversity and complexity of the inner shelf, Canadian Arctic Archipelago, based on LiDAR and multibeam sonar surveys

2020 ◽  
Vol 57 (1) ◽  
pp. 123-132
Author(s):  
John Shaw ◽  
D. Patrick Potter ◽  
Yongsheng Wu
Keyword(s):  
Sea Level ◽  
Gas Hydrate ◽  
Canadian Arctic ◽  
Slight Modification ◽  
The Arctic ◽  
Canadian Arctic Archipelago ◽  
Beach Ridge ◽  
Terrestrial Lidar ◽  
Sea Levels ◽  
Glacial Landforms

Data from two surveys by multi-beam sonar and two by marine/terrestrial LiDAR are used to evaluate the geomorphology of the seafloor in littoral areas of the Canadian Arctic Channels, near King William Island, Nunavut. Submarine terrains show well-preserved glacial landforms (drumlins, mega-scale glacial lineations, iceberg-turbated terrain, recessional moraines, and glaciofluvial landforms) with only slight modification by modern processes (wave action and sea-ice activity). At Gjoa Haven the seafloor is imprinted by fields of pits 2 m wide and 0.15 m deep. They may result from gas hydrate dissolution triggered by falling relative sea levels. The Arctic Archipelago displays what might be termed inverted terrains: marine terrains, chiefly beach ridge complexes, exist above modern sea level and well-preserved glacial terrains are present below modern sea level. This is the inverse of the submerging regimes of Atlantic Canada, where glacial terrains exist on land, but below sea level they have been effaced and modified by marine processes down to the lowstand depth.

scholarly journals Palaeoenvironmental Interpretation of Late Quaternary Marine Molluscan Assemblages, Canadian Arctic Archipelago

2002 ◽  
Vol 54 (3) ◽  
pp. 301-315 ◽  
Author(s):  
Sandra Gordillo ◽  
Alec E. Aitken
Keyword(s):  
Environmental Factors ◽  
Species Composition ◽  
Continental Shelf ◽  
Marine Sediments ◽  
High Latitude ◽  
Late Quaternary ◽  
Canadian Arctic ◽  
High Arctic ◽  
Canadian Arctic Archipelago ◽  
Preservation Potential

Abstract This study examines neonto- logical and palaeontological data pertaining to arctic marine molluscs with the goal of reconstructing the palaeoecology of Late Quaternary ca. 12-1 ka BP glaciomarine environments in the Canadian Arctic Archipelago. A total of 26 taxa that represent 15 bivalves and 11 gastropods were recorded in shell collections recovered from Prince of Wales, Somerset, Devon, Axel Heiberg and Ellesmere islands. In spite of taphonomic bias, the observed fossil faunas bear strong similarities to modern benthic molluscan faunas inhabiting high latitude continental shelf environments, reflecting the high preservation potential of molluscan taxa in Quaternary marine sediments. The dominance of an arctic-boreal fauna represented by Hiatella arctica, Mya truncata and Astarte borealis is the product of natural ecological conditions in high arctic glaciomarine environments. Environmental factors controlling the distribution and species composition of the Late Quaternary molluscan assemblages from this region are discussed.

scholarly journals Regional variability of acidification in the Arctic: a sea of contrasts

2013 ◽  
Vol 10 (2) ◽  
pp. 2937-2965 ◽  
Author(s):  
E. E. Popova ◽  
A. Yool ◽  
A. C. Coward ◽  
T. R. Anderson
Keyword(s):  
Sea Ice ◽  
Primary Production ◽  
Arctic Ocean ◽  
Canadian Arctic ◽  
Atmospheric Co2 ◽  
The Arctic ◽  
Canadian Arctic Archipelago ◽  
Climate Feedbacks ◽  
Regional Variability ◽  
The Arctic Ocean

Abstract. The Arctic Ocean is a region that is particularly vulnerable to the impact of ocean acidification driven by rising atmospheric CO2, negatively impacting calcifying organisms such as coccolithophorids and foraminiferans. In this study, we use an ocean general circulation model, with embedded biogeochemistry and a full description of the carbon cycle, to study the response of pH and saturation states of calcite and aragonite to changing climate in the Arctic Ocean. Particular attention is paid to the strong regional variability within the Arctic and, for comparison, simulation results are contrasted with those for the global ocean. Simulations were run to year 2099 using the RCP 8.5 (the highest IPCC AR5 CO2 emission scenario). The separate impacts of the direct increase in atmospheric CO2 and indirect effects via climate feedbacks (changing temperature, stratification, primary production and fresh water fluxes) were examined by undertaking two simulations, one with the full system and the other in which ocean-atmosphera exchange of CO2 was prevented from increasing beyond the flux calculated for year 2000. Results indicate that climate feedbacks, and spatial heterogeneity thereof, play a strong role in the declines in pH and carbonate saturation (Ω) seen in the Arctic. The central Arctic, Canadian Arctic Archipelago and Baffin Bay show greatest rates of acidification and Ω decline as a result of melting sea ice. In contrast, areas affected by Atlantic inflow including the Greenland Sea and outer shelves of the Barents, Kara and Laptev seas, had minimal decreases in pH and Ω because weakening stratification associated with diminishing ice cover led to greater mixing and primary production. As a consequence, the predicted onset of undersaturation is highly variable regionally within the Arctic, occurring during the decade of 2000–2010 in the Siberian shelves and Canadian Arctic Archipelago, but as late as the 2080s in the Barents and Norwegian Seas. We conclude that, in order to make future projections of acidification and carbon saturation state in the Arctic, regional variability needs to be adequately resolved, with particular emphasis on reliable predictions of the rates of retreat of the sea-ice which are a major source of uncertainty.

scholarly journals Role of sea level pressure in variations of the Canadian Arctic Archipelago throughflow

2021 ◽  
Author(s):  
Zhang Yu ◽  
Chen Chang-Sheng ◽  
Shen Xin-Yi ◽  
Xu Dan-Ya ◽  
Shao Wei-Zeng ◽  
...  
Keyword(s):  
Sea Level ◽  
Canadian Arctic ◽  
Canadian Arctic Archipelago ◽  
Sea Level Pressure ◽  
Level Pressure

scholarly journals Supplemental Material: Biostratigraphy, Age, and Paleoenvironment of the Pliocene Beaufort Formation on Meighen Island, Canadian Arctic Archipelago

2021 ◽  
Author(s):  
René W. Barendregt ◽  
et al.
Keyword(s):  
Marine Sediments ◽  
Canadian Arctic ◽  
Canadian Arctic Archipelago

Table S1: Fossils from Unit C on Meighen Island: 3-3-11, 3-3-12, 3-3-13, 3-3-14, 3-3-15, 3-3-16, 4-4-17, 4-4-18, 9-12-19, 9-12-20, 9-12-21, 11-15-22, 13-17-23, 14-18-24. Table S2: Site-locality-sample naming schemes, numbered from approximately east to west and south to north. Table S3: Fossils from Unit B (the muddy beds) at sites near Bjaere Bay on Meighen Island: 5-6-5, 5-6-6, 5-6-7, 13-17-8. Table S4: Fossils from Unit A, below the marine sediments in the Bjaere Bay region, Meighen Island: 12-16-2, 10-14-3, 1-1-4. Table S5: Fossils from Unit C2 above Unit D in the Bjaere Bay region of Meighen Island: 2-2-1, 7-8-9, 7-8-10. Table S6: Fossils from Unit D at site 7, localities 8, 9, and 10. Table S7: Macrofossils from site likely within Unit C, from Kuc (1974). Table S8: Foraminiferal sample and specimen information.

scholarly journals Supplemental Material: Biostratigraphy, Age, and Paleoenvironment of the Pliocene Beaufort Formation on Meighen Island, Canadian Arctic Archipelago

2021 ◽  
Author(s):  
René W. Barendregt ◽  
et al.
Keyword(s):  
Marine Sediments ◽  
Canadian Arctic ◽  
Canadian Arctic Archipelago

Table S1: Fossils from Unit C on Meighen Island: 3-3-11, 3-3-12, 3-3-13, 3-3-14, 3-3-15, 3-3-16, 4-4-17, 4-4-18, 9-12-19, 9-12-20, 9-12-21, 11-15-22, 13-17-23, 14-18-24. Table S2: Site-locality-sample naming schemes, numbered from approximately east to west and south to north. Table S3: Fossils from Unit B (the muddy beds) at sites near Bjaere Bay on Meighen Island: 5-6-5, 5-6-6, 5-6-7, 13-17-8. Table S4: Fossils from Unit A, below the marine sediments in the Bjaere Bay region, Meighen Island: 12-16-2, 10-14-3, 1-1-4. Table S5: Fossils from Unit C2 above Unit D in the Bjaere Bay region of Meighen Island: 2-2-1, 7-8-9, 7-8-10. Table S6: Fossils from Unit D at site 7, localities 8, 9, and 10. Table S7: Macrofossils from site likely within Unit C, from Kuc (1974). Table S8: Foraminiferal sample and specimen information.

Sign in / Sign up

Export Citation Format

Share Document