Gravity measurements in the Slave and Bear structural provinces, Northwest Territories
R W Hornal, J B Boyd · 1972
Sorne 4,700 gravity observations were used to compile seven Bouguer anomaly maps at a scale of 1:500,000 covering an area of the Canadian Shield bounded by latitudes 620 and 700 N and longitudes 1040 and 1200 W. An eighth map within these boundaries has previously been published (Hornal, 1968). The area includes the Bear and Slave Structural Provinces and portions of the Churchill Structural Province and the Interior Plains. Gravity highs occur over the basic volcanics of the Yellowknife Group. A 30 mgal gravity high over the East Arm of Great Slave Lake is associated with basic intrusions beneath or within the sediments of the Great Slave Supergroup. A steep gravity gradient, extending from Artillery Lake to the Western River at the boundary between the Slave and Churchill Structural Provinces, is attributed to a density contrast between basement gneisses in the Churchill Structural Province and a large granite batholith in the Slave Province. A continuation of the Coppermine River High over large areas of western Victoria Island may indicate the northward extension of the basaltic flows of the Coppermine River Group beneath the Paleozoic sediments. Local gravity lows in excess of 20 mgal are underlain by the Dubawnt sandstone and the sandstones of thé Parry Bay Formation.