Analysis of a marine core from M’Clintock Channel, NWT

micromorphological and geochemical evidence for mass flows and ice shelf grounding

Abstract

Recent work in the Canadian Arctic Archipelago (CAA) has suggested that marine-based deglaciation following the Last Glacial Maximum (LGM) was marked by the formation of extensive ice shelves in the inter-island channels, with further deglaciation resulting in a series of large ice shelf readvances. M’Clintock Channel is a waterway within the CAA that was a primary channel for the ice shelves flowing into Viscount Melville Sound (VMS) during the period primary channel for the ice shelves flowing into Viscount Melville Sound (VMS) during the period following the LGM as evidenced by well-developed ice shelf moraines and sea-floor megascale glacial lineations. A sediment core (2016805-0041GC) from a basin at the northern end of M’Clintock Channel, imaged using x-ray, exhibits macro-scale units of heavily disturbed laminations bordered by undisturbed bedding. This project uses thin section analysis, hyperspectral imaging, and X-ray fluorescence data to gain an improved understanding of the depositional history captured in the sediment core. Thin-section analysis of sediment micromorphology, structure, and microfabric is a commonly used approach in the investigation of soils and terrestrial glacigenic materials. However, within the scope of Arctic marine deposits recovered via sediment coring, it is a relatively new practice despite the potential the technique has for assisting in the determination of the environment and mechanisms of deposition in glacially-influenced marine settings. Utilizing this technique, as well as a variety of other sedimentological tools, we have determined that sediments in this core are clay and carbonate rich. Sedimentary structures in the core suggest several mass flows were deposited through turbidity currents, and gravity flows.

Faculty Mentor: Hilary Corlett

Department: Earth and Planetary Sciences