Base de données de recherche des TNO

étiquettes: physical sciences, sedimentology, stratigraphy, glacial deposits

Objectif(s): To collect small sediment/pebble samples from known terrestrial glacial deposits at coastal exposures and to compare these with the marine glacial deposits found at the shelf edge and slope.

Description du projet: This proposed research focuses on the collection of small sediment/pebble samples from known terrestrial glacial deposits at coastal exposures at various locations in the Inuvialuit Settlement Region (ISR). These sites each have different stratigraphic settings and existing published interpretations of glacial source and providence. The results from these investigations should enable direct comparison with the marine glacial deposits found at the shelf edge and slope and thereby allow us to interpret their depositional environment (from moving terrestrially sourced ice, floating/grounded ice sheets, or glaciomarine environments). The research team is confident that this study will assist in appraising the geohazard that these sediments may pose to offshore oil and gas exploration and development. The research is non-invasive and no substantive disturbance to aquatic or terrestrial wildlife or habitats is anticipated. The proposed project is fully supported under the Beaufort Sea Activity under Natural Resources Canada’s Public Safety Geoscience Program and the Polar Continental Shelf program. The work will take place at coastal exposures on both Crown Lands and Inuvialuit Private Lands in the ISR over approximately 10 days. Field techniques are very simple. 1) A detailed description of the exposure is conducted including photography and 2) Small (half fist-sized) sediment and pebble specimens are collected using hand-tools such as a shovel and pick-ax. Work at Herschel Island and North Head will be based from a small (3-4 people), short-duration (2-3 days) field camp. Work at Banks Island will be by day-trip via helicopter out of Sachs Harbour. The samples collected in the field will be analyzed in a laboratory with various techniques to determination of source of cobble and pebble rock types. By sampling frozen sediments (i.e. permafrost) the research team will also be able extract pore waters from the sediment to characterize their geochemistry. This will again provide a comparison with the marine observations. Polar Continental Shelf funding has been secured for August 2014 for a twin otter on tundra tires to mobilize a small 3-4 person fly camp to Herschel Island and North Head and for day trips to various sites on Banks Island from Sachs Harbour. Local access will be on foot or using a small zodiac boat with a 9.9 HP outboard motor. This research strives to understand the origin of glacial sediments found in the offshore Beaufort Sea and forms part of a larger activity to study geohazards in this setting. The knowledge gained will be useful to regulators, industry and northerners who will be reviewing proposed plans for exploration in the outer shelf and upper slope areas. The fieldwork for this study will be conducted from August 6, 2014 to August 17, 2014.