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Canadian North Atlantic Margins |
Graduate College of Marine Studies, University of Delaware, Newark, DE 19716, USA
The Emerald Basin is a shallow, ice-scoured marine basin located on the central Scotian Shelf. Rock magnetic analyses were performed on (1) four piston cores (H87003-002, 004 and 006; H88-010-005) extracted from the central portion of the basin, (2) outctrop samples collected from 11 sites on the Nova Scotian mainland and (3) a borehole sample collected from the Gulf of St Lawrence. The results of these analyses show that the rock magnetic data have a consistent pattern throughout the Emerald Basin. In particular, magnetic mineral compositional and grain size parameters show a significant change between about 11 and 10 ka, implying a change in sedimentation patterns associated with the Younger Dryas chronozone. Further, the results of these analyses suggest that the rock magnetic data can be used to differentiate between potential sediment sources from the northwest and southeast sides of the mainland. No evidence of red beds from the northwest of the mainland entering the basin is observed, suggesting that sediments from the Gulf of St Lawrence side of Nova Scotia bypassed the shelf, probably being transported to the deep sea via the Laurentian Channel.