ON FOLDS AND THRUSTS AFFECTING THE COPPERMINE RIVER GROUP, NORTHWESTERN CANADIAN SHIELD

Examination of existing geological and aeromagnetic maps of the Coppermine homocline reveals two periods of deformation which affect rocks of the Coppermine River Group but predate rocks of the Rae Group. The oldest event generated easterly-trending folds and southerly-vergent thrust faults and is probably related to events along the northern margin of Laurentia. The younger event caused northerly-trending folds, possibly correlates with an east-west compressional event seen in the subsurface of the Interior Plains, and was likely a result of plate interactions along the western margin of Laurentia. Both deformational events that affect the Coppermine homocline are younger than 1267 Ma and are not correlative with the pre-1268 Ma Racklan orogeny of the northern Cordillera.