Abstract The greatest concentrations of plutonic rocks in the Canadian Cordillera are in the Coast and Omineca belts but significant amounts also occur in adjacent belts. Most Cordilleran plutons are Late Triassic to Paleogene in age, and are coeval and comagmatic with volcanic rock suites. Proterozoic and Paleozoic plutons of ancestral North America consist of Early and Middle Proterozoic granodiorite, Late Proterozoic alkalic plutons, early Paleozoic alkalic to carbonatitic suites, and Proterozoic and Paleozoic mafic sills and diatremes. The pericratonic Kootenay Terrane contains granite to quartz diorite intrusions of mainly Ordovician to Mississippian age. The Monashee Terrane has Proterozoic and Paleozoic(?) alkaline intrusions. The Slide Mountain Terrane contains a variety of Paleozoic plutons, mostly diorite, quartz porphyry, and tonalite. The Alexander Terrane includes Ordovician to Early Silurian calc-alkaline plutons; mid- to Late Silurian sodic plutons emplaced during the Klakas orogeny; and, in the Saint Elias Mountains, late Paleozoic calc-alkaline stocks and batholiths. Wrangellia has small mafic to ultramafic plutons in the Saint Elias Mountains and Devonian quartz-feldspar porphyry in southwestern British Columbia. Late Triassic plutons are largely restricted to small, Alaskan-type ultramafic bodies in Quesnellia and Stikinia, and to a belt of tholeiitic to calc-alkaline granitoid rocks that intrude Stikinia along the Stikine Arch. Both suites are spatially and probably genetically related and are associated with Middle to Upper Triassic volcanic rocks. In the Early Jurassic, plutonic activity occurred in Quesnellia, Stikinia, and Wrangellia. Calc-alkaline batholiths in Quesnellia and alkaline bodies there and in Stikinia show close spatial and temporal

Abstract All pre-Miocene rocks in the Canadian Cordillera have been regionally metamorphosed. The highest grade rocks, reflecting deep burial and high temperatures, form core zones in the Coast and Omineca belts whereas lower grade rocks, suggestive of burial metamorphism, characterize most of the Insular, Intermontane, and Foreland belts. Regional metamorphism reached its peak in the Omineca Belt in Middle Jurassic time and in the Coast Belt in Late Cretaceous time. Both episodes correlate with periods of intense crustal contraction and thickening and were followed by great and rapid uplift. Except for metamorphic culminations in the Deserters Range east of the Northern Rocky Mountain Trench and a local area east of the Southern Rocky Mountain Trench most of the regional metamorphism in the Foreland Belt is of low-grade burial type. Precambrian rocks are commonly in greenschist facies, Paleozoic and some Mesozoic strata are mainly in prehnite-pumpellyite facies, and most Mesozoic strata are in zeolite facies. Although there is a general westward increase in coal rank with increasing stratigraphic burial, several east- to northeasttrending belts of anomalous organic maturation parallel present geothermal gradients. These belts may be related to faults in the Precambrian basement. Rocks in the Omineca Belt received their main metamorphic imprint in Middle Jurassic time, presumably as a result of collision between ancestral North America and the Intermontane Superterrane. Locally, there is evidence for Precambrian metamorphism in the Monashee Complex, pre-Late Mississippian metamorphism in the Kootenay Arc, Late Permian(?) high-pressure and lowtemperature metamorphism in accreted terranes in the southern

Abstract The dominant elements of structural style in the Canadian Cordillera are related to the Insular, Coast, Intermontane, Omineca, and Foreland morphogeological belts, of which the Coast and Omineca belts represent greatly uplifted granitic and metamorphic orogenic core zones. Structures commonly verge outward from the core zones so that, in cross-section, the Cordilleran orogen contains two symmetrical suborogens (Fig. 17.1, in pocket). The first to develop was the Omineca Belt wherein Mesozoic deformation is attributed to the collision of the Intermontane Superterrane with ancestral North America. Orogenesis in the Coast Belt is attributed to the long-lived development of a volcanic-plutonic arc perhaps coupled with collision of the Insular and Intermontane superterranes beginning in Jurassic time. Subsequent dextral strike-slip faulting greatly modified the distribution of components of the amalgamated terranes. Mesozoic and Cenozoic structures in the Insular Belt comprise two main elements: 1) contractional, subduction or accretion related faults and folds in the Saint Elias Mountains and Vancouver Island and 2) dextral strikeslip faults and transpressive folds in the Queen Charlotte Islands. In the Saint Elias Mountains contractional structures are cut by Late Jurassic and Early Cretaceous plutons, and, in the southern Insular Belt, both extension and contraction structures are associated with hypabyssal, felsic dykes, sills and small plutons. On Vancouver Island northwest-trending anticlinoria and northerly trending Early and Middle Jurassic plutons dominate the structural grain; on the Queen Charlotte Islands, similar plutons are of Late Jurassic age. The structurally symmetrical Coast Belt consists of a western part with westward verging

Abstract The Canadian Cordillera is a region of great geological and metallogenic diversity. Just as each Cordilleran terrane preserves a stratigraphic record different from those of neighbouring terranes, characteristic suites of mineral deposits, as integral parts of their host terranes, reflect fundamental differences in their depositional environments. The miogeocline and displaced equivalents in the eastern Cordillera, as well as each of the terranes comprising the accreted collage of the western Cordillera, possess unique lithotectonic characteristics that are reflected in the types of mineral deposits they contain. Predominantly stratiform deposits of Zn, Pb, Cu, Ba, and Fe and skarn deposits of W, Zn, Pb, Mo, and Sn are hosted by layered sedimentary strata of the ancestral North American miogeocline. The similar types of mineral deposits of displaced (Cassiar) and/or deformed (Kootenay, Nisling) continental margin terranes support their cratonal linkage. Stikinia and Quesnellia, which together constitute the bulk of the Intermontane Superterrane, host a suite of mineral deposits typical of their predominantly calc-alkalic volcanic-arc composition: abundant porphyry Cu,Mo deposits, Cu, Zn volcanogenic massive sulphides, Cu and Au skarns, and Au,Ag veins. On the other hand, the ophiolitic Cache Creek and Slide Mountain terranes of the Intermontane Superterrane display distinctive kinds of mineral deposits typical of their oceanic origin: magmatic Cu,Ni, volcanogenic Cu,Zn and mesothermal Au veins, in addition to ultramafic pluton-related asbestos, jade, Cr and platinum group element (PGE) deposits. The dominantly arc volcanic character of the diverse terranes of the Coast Belt is reflected in their metallogeny: volcanogenic Cu,Zn, porphyry Cu,Mo,

Abstract This display illustrates the geological architecture,tectonic style and geophysical expression of the northern Canadian Pacific continental margin in the vicinity of the modern triple junction between the Pacific,America and Juan de Fuca Plates. In addition to active transform and convergent tectonics, the region embraces the junctions between allochthonous, or suspect terranes. The tectonic history, distribution and suture between two of these terranes, Wrangellia and the Alexander Terrane, is partly based upon interpretations of geophysical data beneath water-covered areas and, as such, is somewhat conjectural The sources of information for the display are published and unpublished maps, reports and data files of the Geological Survey of Canada, Earth Physics Branch, Departments of Geology and of Geophysics and Astronomy, both at the University of British Columbia, and the Geological Branch of the British Columbia Ministry of Energy Mines and Petroleum Resources. Unpublished geophysical and subsurface sample information has been provided by Chevron Standard Ltd. and Shell Canada Resources Ltd.