NWT RESEARCH DATABASE

Regions: North Slave Region

Tags: physical sciences, paleogeology, geography, magnetism, Yellowknife

Objective(s): To conduct a detailed paleomagnetic study of the 2.7-billion-year-old Kam Group at the Giant section with the intention of the project is to constrain the paleogeographic location of the Slave craton in the Archean and its relationship with other coexisting cratons around that time.

Project Description: This licence has been issued for the scientific research application No.5354. The research team aim to conduct a detailed paleomagnetic study of the 2.7-billion-year-old Kam Group at the Giant section, ~ 5 km north of the city of Yellowknife. The intention of the project is to constrain the paleogeographic location of the Slave craton in the Archean and its relationship with other coexisting cratons around that time. Currently, no good constraint is available. The well-dated Kam Group provides an opportunity for our goal. The team aim to collect 500 oriented paleomagnetic cores and analyze their magnetization using a state-of-the-art magnetometer at the Paleomagnetism Laboratory at Harvard University. The magnetization will be able to tell us the paleo-latitude and paleo-azimuth information of the Slave craton, which combined with other geological evidence, will constrain the paleogeography of the craton 2.7 billion years ago. The main method is paleomagnetism, which is the only quantitative tool to constrain the paleolatitude and orientation of cratons in Precambrian time. Assuming that the ancient geomagnetic field was a geocentric-axial dipole (GAD), the magnetic remanence of rocks from a given craton is a function of its paleoposition, varying with age. Specifically, the inclination can inform the paleolatitude of the craton, that is, a steep inclination would indicate a high latitudinal position, and a shallow inclination would indicate a low latitudinal position. The major targets of this proposal are the mafic pillow lavas and the massive flows of the Kam Group. Portable, lithium-ion-battery-powered drills will be used in the field to collect 8-10 rock cores from each flow. Each core is about 2.2 cm in diameter and 5-8 cm in length. Cores will be oriented by a magnetic compass. Paleomagnetic sampling will sufficiently cover each flow of the Kam Group, supplemented by necessary field and statistical tests to evaluate the quality of paleomagnetic results. While the project is essentially academic in scope, it is ultimately hoped that the work will provide a wider understanding of the landscape and geology around the Yellowknife area. Should the results show the potential to impact nearby communities of the Yellowknife area in any form, community-engagement activities with the nearest community will be planned in the Spring 2023/Fall 2023 period, in order to provide the residents with a better foundation for land-use decisions. The research team will also keep active communication with the staff from the Northwest Territories Geological Survey and the people of local communities. The fieldwork for this study will be conducted from January 1, 2023 to December 31, 2023.