Tectonic Framework

Abstract This subchapter is concerned only with the tectonics affecting the Phanerozoic sedimentary cover of the Interior Platform, western basins, and eastern Cordillera and with those Upper Proterozoic deposits genetically related to them. Interpretation of the sedimentary and tectonic history of pre-Late Proterozoic time is subject to uncertainties much greater than those of Phanerozoic history, and Phanerozoic rocks are the principal focus of this volume. Precambrian tectonics as determined from stratified rocks is dealt with in Subchapter 4A, and the geology of the sparsely sampled and remotely sensed crystalline basement in Chapter 3. Furthermore, this subchapter is concerned only with those sedimentary successions that were deposited upon or in immediate connection with North America; the extremely complex history of the accreted terranes to the west is beyond the compass of this volume, and in any case is not recorded by the strata of the Western Canada Basin. The accreted terranes are fully treated by Gabrielse and Yorath (1991). In this subchapter only the most critical sources are cited; all significant literature is cited in Chapter 4. The region of concern here has generally been treated as the Western Canada Basin, a term useful only in designating a geographic area underlain entirely by sedimentary rocks. Most of the “basin”, as conventionally outlined, was a tectonic and sedimentary platform (“shelf” of some authors) during the divergent-margin phases of sedimentation, a part of it was a platform during the convergent-margin phases, and it has been a tectonic platform for most of Tertiary time. where