Dudley D. Rice, 1983. "General Characteristics of the Cretaceous Western Interior Seaway and Basin", Patterns of Sedimentation, Diagenesis, and Hydrocarbon Accumulation in Cretaceous Rocks of the Rocky Mountains, Dudley D. Rice, Donald L. Gautier
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Cretaceous rocks of the Rocky Mountain area were formed from sediments deposited in an elongate, asymmetrical foreland basin that was periodically occupied by a shallow epicontinental seaway. The basin formed in Late Jurassic time by subduction of the oceanic crust beneath the North American craton. The area of both maximum subsidence (related to crustal loading by thrust plates) and sedimentation (related to erosion and redistribution of the load) was located on the west side of the basin adjacent to the Cordillera thrust belt. Further east in the foreland basin, deposition was affected by recurrent movement of tectonic features, such as the Transcontinental Arch. The Cretaceous section is characterized by large-scale cyclothems (transgressive-regressive oscillations) that were controlled by (1) global sea-level changes, and (2) major episodes of thrusting in the Cordillera. The cyclothems are strongly asymmetric with the volumetrically largest part of the sequence representing deposition during progradation. Consistent patterns of sedimentation were established that were controlled mainly by the supply of clastics from the west. In general, facies belts are aligned in a north-south direction with coarser grained clastics to the west and thinner sequences of carbonate-rich rocks to the east. Carbonate-rich facies were deposited in the central part of the basin only during times of maximum transgression.