Title | Sedimentology and history of sediment sources to the NW Labrador Sea during the past glacial cycle |
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Author | Rashid, H ; Piper,
D J W ; Drapeau, J; Marin, C; Smith, M E |
Source | Quaternary Science Reviews vol. 221, 105880, 2019 p. 1-17, https://doi.org/10.1016/j.quascirev.2019.105880 |
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Year | 2019 |
Alt Series | Natural Resources Canada, Contribution Series 20190256 |
Publisher | Elsevier BV |
Document | serial |
Lang. | English |
Media | paper; on-line; digital |
File format | pdf (Adobe® Reader®); html |
Province | Newfoundland and Labrador; Nunavut; Northern offshore region |
NTS | 14; 15 |
Area | Labrador; Labrador Sea; Baffin Isalnd; Davis Strait |
Lat/Long WENS | -62.5000 -52.5000 64.0000 58.6667 |
Subjects | marine geology; surficial geology/geomorphology; sedimentology; geochemistry; stratigraphy; geochronology; geophysics; Nature and Environment; Science and Technology; continental margins; continental
slope; glacial history; ice margins; depositional history; sedimentation; marine sediments; landslide deposits; debris flows; turbidites; muds; sediment dispersal; source areas; provenance; marine sediment cores; paleoenvironment; oceanography;
isotopic studies; oxygen isotopes; x-ray fluorescence analyses; radiometric dating; radiocarbon dates; geophysical interpretations; seismic interpretations; geophysical surveys; acoustic surveys, marine; side-scan sonar; bathymetry; facies analyses;
stratigraphic analyses; pebble lithology; geophysical logging; magnetic susceptibility; correlations; Baffin Slope; Hudson Strait Ice Stream; Baffin Island Current; West Greenland Current; Northwest Atlantic Mid-Ocean Channel; Cumberland Sound Ice
Stream; ice streams; ice stream margins; glaciomarine sediments; colluvial and mass-wasting deposits; Phanerozoic; Cenozoic; Quaternary |
Illustrations | location maps; geoscientific sketch maps; geophysical profiles; tables; geophysical images; photographs; profiles; spectra; plots; lithologic sections |
Program | Offshore Geoscience |
Released | 2019 08 26 |
Abstract | The paleoceanography and sediment dynamics of the northernmost Labrador Sea provides critical records of glacial history, glacially-dominated sedimentation, and paleocirculation. A reference core at
938m on the SE Baffin Slope was investigated with new oxygen isotope stratigraphy, X-ray fluorescence geochemistry, and 18 14C-AMS dates and correlated to 14 regional deep-water cores. The reference core provides a paleoceanographic and sediment
source record over the last 40 ka, overlying a 3-m-thick blocky mass-transport deposit over MIS 5 autochthonous sediment. Detrital carbonate-rich sediment layers H0-H4, based on bulk geochemistry, were derived principally from Hudson Strait. Shortly
after H2 and H3, the shelf-crossing Cumberland Sound ice stream supplied dark brown ice-proximal stratified sediments. Minor supply of carbonate-rich sediment from Baffin Bay allows chronologic integration of the Baffin Bay and Labrador Sea detrital
carbonate records and implies an open seaway through Davis Strait. The counterparts of H3, H4, and (?)H5 events in the deep Labrador basin are 4-10m thick units of thin-bedded carbonate-rich mud turbidites from glacigenic debris flows on the Hudson
Strait slope. The behavior of the Hudson Strait ice stream changed through the last glacial cycle. In H1 and H2, the ice stream retreated back across the shelf but did not deglaciate Hudson Bay; in H3eH5 it remained at the shelf break long enough to
supply thick turbidites, and subsequent retreat after H4 and H5 deglaciated Hudson Bay. The maximum extent of ice streams in Hudson Strait, Cumberland Sound, and Lancaster Sound was not synchronous. |
Summary | (Plain Language Summary, not published) Synthesis of the glacial history of the SE Baffin continental margin, with implications for geohazards and response to climate change |
GEOSCAN ID | 314867 |
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