LE3 .A278 2023

2023

Eamer, Jordan
King, Edward

Acadia University

Bachelor of Science

Honours

Environmental Geoscience

Earth & Environmental Sciences

St. Anns Basin is a Quaternary offshore intrashelf basin located SE of Cape Breton Island, Nova Scotia. The eastern Scotian Shelf remains a poorly understood area due to its complex physiography reflecting a more meltwater-rich glacial regime (tunnel valley style) as the final ice sheet retreated from the offshore following the Last Glacial Maximum. In this study, an archival sediment core was used that targets a glaciomarine sediment package on the eastern margin of the basin to update the chronology using radiocarbon dating of benthic foraminifera and shell fragments. The sediment core contains suspected brick red mud layers associated with major deglacial ice-calving events, precisely dated in the nearby Laurentian Channel and elsewhere on the Scotian Shelf and Slope. An updated lithostratigraphic section alongside biostratigraphic interpretation was used to provide a framework for the deglacial chronology of the basin, the first for this part of the shelf. The updated chronology also allowed the development of a seismostratigraphic framework for St. Anns Basin to interpret and constrain mass failures found throughout the basin. The mass failures were found to be essentially contemporaneous, occurring ~ 8.2 ka BP, possibly constituting a seismically induced event. The updated timing of these mass transport deposits will allow for a better assessment of the geohazard risk in the basin.

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https://scholar.acadiau.ca/islandora/object/theses:3990