The Upper Jurassic (Oxfordian) to Paleogene (Oligocene) assemblages record the effects of Mesozoic and early Cenozoic terrane amalgamations and collisions which, with consequent orogenesis and sedimentation, created the modern framework of the Canadian Cordillera. During this interval the five geological belts were established, more or less, but not entirely concordantly with major terrane boundaries. The sedimentary basins which developed as a result of and subsequent to terrane accretion reflect the full range of continental and oceanic plate interactions including orthogonal, oblique and transform motions. The assemblages are important hosts to several episodic suites of copper, copper-molybdenum and molybdenum porphyry deposits as well as all of the economic coal deposits of the Cordillera. Additionally, Cretaceous strata in the Foothills of the Foreland Belt serve as reservoirs for many hydrocarbon accumulations.
The tectonic setting within which the assemblages developed was dominated by the accretion of large, composite crustal fragments to the continental margin. The Intermontane Superterrane, comprising the amalgamated components of Stikinia, Quesnellia, the Slide Mountain and Cache Creek terranes probably collided with and subsequently was thrust over the pericratonic terranes at the western edge of North America in Early to Middle Jurassic time. Likewise, the Insular Superterrane, composed of Wrangellia and the Alexander Terrane, together with several smaller terranes in the Coast Belt, accreted to the Intermontane Superterrane no later than mid-Cretaceous time and possibly as early as latest Jurassic to earliest Cretaceous time. The great width of the Canadian Cordillera is a reflection of the dimensions of the successively
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Geology of the Cordilleran Orogen in Canada
Seven stratigraphic chapters cover time slices from Precambrian to Neogene; also included are chapters covering tectonic framework, paleomagnetism, physiographic evolution, Quaternary glaciation, volcanic and plutonic regimes, metamorphism, structural styles, metallogeny, energy and ground resources, and natural hazards. A tectonic synthesis chapter and a summary of outstanding problems round out the volume. Accompanying plates include physiographic, tectonic assemblage, terrane and metamorphic maps, correlation charts, structural cross sections, and special maps showing distribution of Proterozoic and Miocene plutonic suites and the metallogeny of terranes.