Abstract

Easterly trending Tulemalu diabase dykes that cut an area of predominantly Archean rock in southern Keewatin were magnetized more than 2200 Ma ago. Thirteen of the sampled sites (dykes) exhibit a southeast-down remanent magnetization and five sites give a more poorly grouped direction that is reversed to this. Their combined pole is at 122.4°E, 0.5°S, δm = 10.4°, δp = 6.0°. Six northeasterly trending Kazan dykes, which are probably correlatives of the Kaminak dykes, give a metamorphic pole at 94.2°W, 30.7°N, δm = 35°, δp = 31°. The age of their magnetization is thought to be between 1900 and 2000 Ma.The pole for the Tulemalu dykes lies within a group of poles of similar age derived from basic rocks of the Slave Province. It is about 30° away from the pole for the MacKay dykes, which occur north of Great Slave Lake and which have an easterly trend similar to that of the Tulemalu.Poles whose ages range between 1900 and 2200 Ma and that are derived from the Slave, western Churchill, and Superior provinces all suggest that during this period these three continental plates occupied approximately the same relative positions as they do today.

You do not currently have access to this article.