Paleotectonic and stratigraphic boundaries in the western US interior

Conference · Mon Aug 01 04:00:00 EDT 1983 · Am. Assoc. Pet. Geol., Bull.; (United States)

OSTI ID:6497721

Shurr, G W; Rice, D D

Late Cretaceous marine deposition in the western interior of the US occurred in an epicontinental seaway elongate in a north-south direction. In central Montana, the western side of the seaway was characterized by a broad, tectonically active shelf. In eastern Montana and the western Dakotas, an actively subsiding basin was located in the central part of the seaway. In western and central South Dakota, the eastern side of the seaway was a more stable west-sloping ramp. Based on these studies, the authors interpret the stratigraphic variations to be the expression of paleotectonism on discrete basement blocks bounded by fault zones which are observed on Landsat images as linear features. On the western shelf, elevated blocks controlled the sites of the winnowing and deposition of sandstones. Within the basins, subsiding basement blocks were filled by deposition of shales. These basin blocks acted as sediment sinks which inhibited the eastward dispersal of terrigenous materials from the west. On the eastern ramp, chalks were deposited and locally eroded on slightly elevated blocks which were relatively free of terrigenous material. Paleotectonism, therefore, influenced deposition not only on the active western shelf and in the basin, but also on the more stable eastern ramp.

• Research Organization: Geological Survey, Denver, CO
• OSTI ID: 6497721
• Report Number(s): CONF-8309274-
• Conference Information: Journal Name: Am. Assoc. Pet. Geol., Bull.; (United States) Journal Volume: 67:8
• Country of Publication: United States
• Language: English

Related Subjects

58 GEOSCIENCES
580100* -- Geology & Hydrology-- (-1989)
GEOLOGIC STRATA
GEOLOGIC STRUCTURES
GEOLOGY
REGIONAL ANALYSIS
REMOTE SENSING
SEDIMENTARY BASINS
SEDIMENTATION
STRATIGRAPHY
TECTONICS