HR: 10:20h
AN: T22C-01    [Abstracts]
TI: Review of Intraplate Tectonic and Basin Settings
AU: * Kluth, C F
EM: ckluth@mines.edu
AF: Colorado School of Mines, 1945 Illinois Street, Golden, CO 80401 United States
AB: Intraplate deformation continues to be enigmatic in terms of plate tectonics. In many cases where later deformation has obscured the earlier deformation, such as in western North America, much of the records of the tectonic and climatic events are preserved in the stratigraphic record in the basins. In some cases, such as the Eastern Sierra Shear Zone, the deformation can be interpreted as a "soft" cratonic part of the plate boundary, and result in basins at releasing bends in strike-slip systems. Other areas, like central Asia include strike-slip deformation related to plate collisions. Large, low-amplitude arches, domes and basins such as those in the mid-continent may be related to plate boundary tectonics, but others such as the Williston Basin and the Trans-continental arch are more difficult to understand. Thermal events in the crust also produce broad domes that shed sediments, sometimes in all directions. Epirogenic uplifts profoundly affect the level of erosion and the depositional record, but are often difficult to understand in detail. Areas of intracratonic fault-bounded uplifts and basins such as the Laramide features of the western U.S. deform the existing foreland basin. In western US, the first motion of the crust is subsidence so that a precursor basin forms before the uplifts break the craton. Other intracratonic orogens, like the Ancestral Rocky Mountains, appear to be related to plate margin tectonic, but their direct relationship remains problematic. The role of inherited structural features is key in regions of inversion, such as Sundaland and western Europe. In other areas such as the western U.S. inheritance from the Precambrian fabric to Late Paleozoic, Late Cretaceous, and Cenozoic events is obvious in some places and was not a strong tectonic influence in others. Sedimentation in each tectonic province varies according to the amount of uplift and the development of accommodation space. Axial drainage, and large, regional river systems appear to have played a major role in sediment distribution in many basins, such as Death Valley. Early, closed drainages often are followed by regional, integrated drainage and sedimentation. Much work remains in order to understand the relationship of these tectonic settings and their resultant sedimentation and stratigraphic architecture with the crustal and climatic processes that produced them.
DE: 8038 Regional crustal structure
DE: 8103 Continental cratons
DE: 8110 Continental tectonics: general (0905)
SC: Tectonophysics [T]
MN: Fall Meeting 2005