The glacial and Holocene history of Notre Dame Trough, Northeast Newfoundland Shelf

Abstract

This study was conducted on the Notre Dame Trough (NDT) on the Northeast Newfoundland Shelf. The purpose of this project was to help unravel the glacial history, including the timing of a large slide block in the NDT, and to compare the late Quaternary sedimentary record in cores with other places on the Newfoundland margin. Air gun seismic and Olex bathymetry were used to determine that some features present in the NDT are glaciotectonic in origin, and likely formed during the Wisconsinan. A large slide block present in the NDT was analyzed using seismic survey data and down-core shear strength data and showed that this slide block likely post-dates the glaciotectonic deformation. The physical properties of thirteen piston cores and chemical properties of five of the cores were analyzed to classify four main sediment units. Knudsen 3.5 kHz seismic data were used to determine the sedimentary context of the cores. Carbon-14 dates from these cores provide age control for changes in sediment supply and paleoceanographic events such as Heinrich events with high supply of detrital carbonate. The variation in sediment source in the study area indicates that the NDT was largely unaffected by the Labrador current for some time before 14 ka. Correlations between the cores of this study and those of Flemish Pass and Cartwright Saddle have compared the paleoceanographic records and show that Heinrich-0 (ca. 12 ka) can be correlated between NDT, Flemish Pass and Cartwright Saddle. However, based on Carbon-14 dates, Heinrich-1 is not marked by a detrital carbonate layer in Notre Dame Trough. A red mud bed correlated between several cores may represent a synchronous meltwater discharge event from ice in St Anthony Basin.