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TitleProvenance of sediment in the Labrador Current: a record of hinterland glaciation over the past 125 ka
AuthorMao, L; Piper, D J W; Saint-Ange, F; Andrews, J T; Kienast, M
SourceJournal of Quaternary Science vol. 29, issue 7, 2014 p. 650-660,
Alt SeriesEarth Sciences Sector, Contribution Series 20130249
PublisherJohn Wiley and Sons
Mediapaper; digital; on-line
File formatpdf
ProvinceEastern offshore region; Northern offshore region
NTS3; 14; 15; 16; 27; 28; 38; 39
AreaLabrador Sea; Flemish Cap; Canada
Lat/Long WENS -80.0000 -32.0000 78.0000 46.0000
Subjectssediment transport; glacial history; glacial deposits; clay minerals; sandstones; calcite; dolomites; provenance; Heinrich events; Hudson Strait
Illustrationslocation maps; cross-sections, stratigraphic; graphs; tables
ProgramMarine Geohazards, Public Safety Geoscience
Released2014 10 15
AbstractThe Labrador Current flows southward along the continental margin off eastern Canada and is the principal source of sediment to the outer continental margin areas where ice sheets did not cross the continental shelf. We present multi-proxy mineralogical and geochemical records based principally on X-ray diffraction and X-ray fluorescence for core 2011031-059 from northern Flemish Cap to determine changes in supply and hence to reconstruct provenance evolution during the last glacial cycle. The calcite to dolomite ratios in Heinrich layers ranged from 2 to 4, suggesting carbonate layers derived from Hudson Strait as early as Marine Isotope Stage (MIS) 5a-d. Mineral abundance shows three time-dependent predominant sediment sources other than in Heinrich layers: (i) Baffin Bay shelves and adjacent land in MIS 5 and 1, with high Ca, Sr, kaolinite and feldspars and low clay minerals and calcite/dolomite ratios; (ii) Labrador in MIS 3, with low clays and grey color; and (iii) north-east Newfoundland Shelf in MIS 2 and 4, with higher concentrations of clay minerals, red sandstones and transition elements. These results allow a reconstruction of principal ice streams supplying the north-west Atlantic over the last full glacial cycle.
Summary(Plain Language Summary, not published)
The source, and hence composition, of sediment near the Mizzen oilfield in Flemish Pass changes in a systematic manner depending on the past extent of glacial ice in Eastern Canada. Such data may be used to improve geotechnical understanding of landslide risk, even in sub-seafloor intervals too deeply buried to sample.