J.C. Wendte, 1992. "Platform Evolution and its Control on Reef Inception and Localization", Devonian-Early Mississippian Carbonates of the Western Canada Sedimentary Basin: A Sequence Stratigraphic Framework, Jack Wendte, Frank A. Stoakes, Clarence V. Campbell
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Many ancient biohermal carbonate reefs occur on areally extensive, shallow marine carbonate platforms. Because these reefs are imposing structures in outcrop and contain significant hydrocarbon reserves in the subsurface, they have been studied in detail. These studies have concentrated on their facies, paleontology, reservoir attributes, and more recently on reef evolution. Only a few studies have focused on their origin. Furthermore, the internal anatomy of carbonate platforms, from which these reefs evolved, has received only minor attention in the WCSB. As a consequence, models explaining the temporal and spatial distribution of biohermal reefs are very speculative.
This paper addresses the question of the origin of large Devonian platform-reef complexes in the WCSB. Why do these reefs form during specific episodes and in certain locations?
Large areally extensive biohermal reefs occur in two main stratigraphic intervals in the WCSB: the late Givetian Swan Hills reef complexes of west-central Alberta and the early to middle Frasnian reefs of both east-central and west-central Alberta. These reefs are distinctly different from either earlier Keg River reefs or later Nisku reefs in that they attained much greater areal extent, commonly in excess of 10 km2 and up to 600 km2, and nucleated on shallow-water carbonate platforms. Keg River and Nisku reefs, on the other hand, are normally less than 1 km2 in size and formed on underlying carbonate ramps.
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Devonian-Early Mississippian Carbonates of the Western Canada Sedimentary Basin: A Sequence Stratigraphic Framework
The Devonian and early Mississippian strata in the Western Canada Sedimentary Basin include a wide diversity of shallow-water carbonate and basin filling carbonate, shale and evaporite facies. Of these, the large Devonian platform-reef complexes are the most spectacular. They occur in magnificent exposures in the Front Ranges of the Canadian Rockies and in the subsurface of Alberta. In the subsurface, these complexes pool many of the largest oil and gas accumulations in Western Canada. This short course is intended to provide a summary of Devonian and early Mississippian deposits in the subsurface of the Western Canada Sedimentary Basin. One of the major goals is to present the evolution of these strata in a sequence-stratigraphic context. The role of sea-level, tectonic and depositional controls on “stacking” and facies patterns are considered. A second major goal is to relate the occurrence of hydrocarbon pools to this sequence-stratigraphic framework.