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TitreSedimentology and history of sediment sources to the NW Labrador Sea during the past glacial cycle
AuteurRashid, H; Piper, D J W; Drapeau, J; Marin, C; Smith, M E
SourceQuaternary Science Reviews vol. 221, 105880, 2019 p. 1-17, https://doi.org/10.1016/j.quascirev.2019.105880
Année2019
Séries alt.Ressources naturelles Canada, Contribution externe 20190256
ÉditeurElsevier BV
Documentpublication en série
Lang.anglais
DOIhttps://doi.org/10.1016/j.quascirev.2019.105880
Mediapapier; en ligne; numérique
Formatspdf (Adobe® Reader®); html
ProvinceTerre-Neuve-et-Labrador; Nunavut; Région extracotière du nord
SNRC14; 15
Lat/Long OENS -62.5000 -52.5000 64.0000 58.6667
Sujetsmarges continentales; talus continental; antecedents glaciaires; marges glaciaires; antecedents de sedimentation; sedimentation; sédiments marins; dépôts de glissement de terrain; coulées de débris; turbidites; boues; dispersion des sédiments; régions émettrices; origine; carottes de sédiment marin; paléoenvironnement; océanographie; etudes isotopiques; isotopes d'oxygène; méthodes de fluorescence aux rayons x; datation radiométrique; datations au radiocarbone; interprétations géophysiques; interpretations sismiques; levés géophysiques; levés acoustiques marins; sonar latéral; bathymétrie; analyses de faciès; analyses stratigraphiques; lithologie des galets; diagraphie géophysique; susceptibilité magnétique; corrélation; courants glaciaires; bordures de courants glaciaires; sédiments glaciomarins; dépôts de versants; géologie marine; géologie des dépôts meubles/géomorphologie; sédimentologie; géochimie; stratigraphie; géochronologie; géophysique; Nature et environnement; Sciences et technologie; Phanérozoïque; Cénozoïque; Quaternaire
Illustrationslocation maps; geoscientific sketch maps; geophysical profiles; tables; geophysical images; photographs; profiles; spectra; plots; lithologic sections
ProgrammeLa géoscience pour les développements extracôtiers de la côte est, Géoscience en mer
Diffusé2019 08 26
Résumé(disponible en anglais seulement)
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.
Résumé(Résumé en langage clair et simple, non publié)
Synthèse de l'histoire glaciaire de la marge continentale du sud-est de Baffin, avec des implications pour les risques géologiques et la réponse au changement climatique
GEOSCAN ID314867