FN Archimer Export Format
PT J
TI Late Pleistocene- Holocene architecture and sedimentary processes on the glacially influenced SW Grand Banks Slope off Newfoundland
BT 
AF Gao, Ya
   Piper, David J.W.
   Normandeau, Alexandre
   Xie, Xinong
AS 1:1,2,3;2:2,4;3:2;4:1,5;
FF 1:;2:;3:;4:;
C1 Hubei Key Laboratory of Marine Geological Resources, China University of Geosciences (CUG), Wuhan 430074, PR China
   Natural Resources Canada, Geological Survey of Canada (Atlantic), Bedford Institute of Oceanography, P.O. Box 1006, Dartmouth, Nova Scotia B2Y 4A2, Canada
   Guangdong Provincial Key Laboratory of Marine Resources and Coastal Engineering, Guangzhou, Guangdong 510006, PR China
   Department of Oceanography, Dalhousie University, Halifax, Nova Scotia B3H 4R2, Canada
   Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Zhuhai, 519082, China
C2 UNIV CHINA GEOSCI, CHINA
   GEOL SURVEY CANADA, CANADA
   GDDCE, CHINA
   UNIV DALHOUSIE, CANADA
   UNIV SUN YAT SEN, CHINA
IF 2.9
TC 1
UR https://archimer.ifremer.fr/doc/00788/89986/105096.pdf
LA English
DT Article
CR IMAGES 1-MD101
BO Marion Dufresne
DE ;Fine-grained facies;Contourite;Turbidite;Mixed and hybrid systems;Ice -rafted detritus;Labrador current
AB Complex inter-relationships between alongslope and downslope sediment dispersion exist on glaciated continental margins and vary widely along continental margins depending on sediment supply and bottom current strength. In eastern Canada, proglacial sedimentation rates are relatively high on the SW Grand Banks Slope compared to the sediment starved SE Grand Banks margin, but relatively low compared to the glacially dominated Scotian margin off eastern Canada. As on other parts of the Canadian margin, its late Quaternary sediment architecture has been constructed by interacting alongslope and downslope processes. These include sediment transported by downslope glacial meltwater discharge, alongslope bottom currents and ice-rafting. Based on the analysis of sediment cores going back to 24 ka (Heinrich event 2), this study investigates fine-grained sedimentary facies and the development of variable depositional patterns on the glacially influenced SW Grand Banks Slope off Newfoundland (eastern Canada). Both turbidites and contourites show stratification, but differ in internal structure, the presence of IRD, and the nature of their upper and lower boundaries. Sandy contourites are mostly massive, occurring either as lenses or as part of the ideal bi-gradational vertical sequence with mottled silt-mud. Glacial silty contourites have distinct rhythmic laminae with the long axis of IRD parallel to bedding. Regional scale thickness variations allow discrimination between hemipelagites and muddy contourites. Depositional architecture is built through temporal and spatial coupling of the diverse sedimentary processes. During the last glacial maximum and early deglaciation, turbidity currents fed either by meltwater or oceanographic processes flowed in canyons, and a contourite depositional system developed between the canyons. The two systems interacted on inter-canyon ridges, where contourite sedimentation was not completely overwhelmed by energetic turbidity currents. In the Holocene, alongslope processes became dominant, building a drift with clearly variable thickness, in part related to seabed morphology. A conceptual model is proposed to present the key elements of depositional processes in this depositional system, and a similar evolutionary history can be expected on other distal glacial margins. 
PY 2022
PD SEP
SO Marine Geology
SN 0025-3227
PU Elsevier BV
VL 451
UT 000874781100002
DI 10.1016/j.margeo.2022.106883
ID 89986
ER

EF