Principal geologic and geographic provinces of North America

Principal structural elements of North America in Cambrian and later time

Isopach and lithofacies map of the Cambrian System in North America. Cambrian rocks are probably more extensive than shown, but information about them is sketchy in northern parts of the continent, in the Western Cordillera, and beneath the coastal plains. In areas covered by the limestone pattern, Cambrian rocks are mostly limestone and shale; the shale pattern indicates mostly shale and sandstone; the dotted pattern, mostly sandstone

The Cordilleran region from early Paleozoic to Devonian time. The Cordilleran geosyncline with miogeosynclinal and eugeosynclinal sites of deposition lay west of the continental platform

The Cordilleran region from Devonian to early Triassic time. After the development of the Antler and Sonoma belt, the site of the Paleozoic Cordilleran geosyncline was divided into an eastern geosynclinal belt along the Pacific border

The Cordilleran region in Mesozoic time. By latest Cretaceous time, Nevadan Sevier and Laramide orogenies had created a wide mountainous belt across the Cordillera

Mesozoic plate relations along the Cordilleran margin. Prior to the development of the San Andreas fault, plates of the Pacific Ocean were probably descending beneath the North American plate and creating a subduction zone like the present one along the west coast of South America