Cordilleran Miogeosyncline in North America Geologic Evolution and Tectonic Nature

Steep crustal-scale faults, having their origins in the Late Archean & Early Proterozoic & trending NE-SW, which define the fundamental block lithospheric structure of the North American craton, are seen from geological & geophysical evidence to continue far into the interior of the Lake Proterozoic-Phanerozoic Canadian Cordilleran mobile megabelt. This suggests that variously reworked excratonic basement blocks underlie much of the Cordillera. The western edge of the modern craton is probably near the Rocky Mountain-Omineca belt boundary; the Rocky Mountain fold-&-thrust belt on the east side of the Cordillera is evidently rootless & overlies the undisturbed cratonic basement. Phanerozoic differences between the Cordilleran tectonic belts, resulting from a long, dissimilar, multi-cycle history of waxing & waning orogenesis apparent from the rock record, lie chiefly in the degree of indigenous tectonic remobilization & reworking of the ancient crust.Lyatsky, Henry V. is the author of 'Cordilleran Miogeosyncline in North America Geologic Evolution and Tectonic Nature' with ISBN 9783540661979 and ISBN 3540661972.