Abstract

The Stuart River and Caribou Lake areas of northeastern Cornwallis Island, Nunavut are dominated by Middle Ordovician to Upper Silurian carbonate and shale, and Lower to upper Middle Devonian carbonate and sandstone. These units have been thrust faulted and have undergone multiple phases of folding. Four deformational events are recognized. D1 develops NNW-SSE trending F1 folds and associated thrusts in Ordovician and Silurian strata. D1 is correlative with movement on the Boothia Uplift (Late Silurian-Early Devonian). D2 develops F2 folds and west-directed thrust faults that are co-axial with F1 but affect late Middle Devonian and older strata. D3 exhibits east-west trending F3 folds and is correlated with the Ellesmerian Orogeny (Late Devonian to Early Carboniferous). F3 folds re-fold F1/F2 folds creating interference patterns at a variety of scales. D4 is defined by northwest-southeast trending F4 folds. F4 folds overprint F1/F2 folds, and are unaffected when axial surfaces of F3 are crossed. D4 may possibly be associated with the Paleogene Eurekan Orogeny. Hydrothermal dolomite and Zn-Pb mineralization are strongly controlled by pre-exisiting structures. Specifically, they correlate most commonly with thrusts (preferentially east-directed thrusts) and along the hinge surface traces of regional F3 folds.