NWT RESEARCH DATABASE

Regions: North Slave Region

Tags: physical sciences, geological mapping, stratigraphy, industrial development, ground ice, topography, aggregate resources

Project Description: Sand, gravel and crushed stone are valuable geological resources, collectively known as aggregates. They are essential bed, foundation and building materials. The presence of massive ice in aggregate deposits results in a series of resource management problems, particularly for the oil industry and its contractors who rely on local granular deposits as building material. From an environmental perspective, there is the problem of thermokarst and terrain instability that results when these deposits are disturbed. From a development perspective, there are problems of extraction and overestimation of reserves. In order to understand massive ice occurrence, we will combine a variety of remote-sensing and geophysical tools to map ground ice sites in granular deposits. Collection of ice and sediment samples from two or more sites will also occur, if there is active granular removal in the region at the time of our visit, to understand the stratigraphic relationships between the aggregates and massive ground ice presence. We will use existing roads and ice roads, and/or helicopter to visit the sites. The researchers will use skidoos if necessary to get to the sites away from the road. We will perform three types of passive, non-invasive surveys: a high resolution GPS (Trimble System), a Ground Penetrating Radar (GPR) survey, and a capacitive-coupled resistivity geophysical tool (A Geomatics Ohm-Mapper system) in order to better understand the granular resources with massive ice present. This will be done by walking or skidoo-travel over the sites while carrying the survey equipment. Small ice and sediment (~1 L) samples will be collected from natural massive ice exposures or by ice exposed during granular extraction (if taking place). In regard to helicopter use, the helicopter will stay with the scientists in order to reduce the number of flights. Helicopter flights will adhere to recommendations by the Wildlife Management Advisory Council (NWT) for minimum flight altitudes. Copies of research reports and scientific publications will be sent to all stakeholders at the expiration of the research. The study will be conducted from November to December, 2005 at the following locations: Carat Lake Esker and Delta (between 66º N and 66º 5’ N and between 111º 25’ W and 111º 30’ W); Izok Lake Esker (65º 42’ N and between 112º 50’ W and 112º 55’ W); BHP Koala Airstrip Esker (64º 41’ N and 110º 36’ W); Misery Lake Esker (64º 35’ N 110º 10’ W); Diavik (East Island) (between 64º 28’ N and 64º 31’ N and between 110º 16’ W and 110º 25’ W).