Tectonics of Central Wyoming: ABSTRACT
Central Wyoming is bounded by mountain ranges which have moved along complex thrust faults. Some of these ranges lie on or very close to the basin deeps. Subsequent adjustment by normal faulting has further complicated much of the area. Crustal shortening is demonstrated, whereby tightly folded anticlines have formed within the basins and have moved along thrust faults upon the mountain flanks. The area apparently acted under the conditions of plastic deformation, in response to a series of pulsating movements affecting the entire Rocky Mountain area during Laramide time. The tectonic pattern of the area was influenced by the sedimentary column. A relatively thin column of Paleozoic and Mesozoic rock represents transgressive overlap from the Cordilleran geosyncline. This thin column occupied a relatively stable area until Laramide time. Regional isopach work, however, indicates broad gentle arching throughout the sedimentary history. As early as Frontier time considerable local relief was present, and some folds were overturned in pre-Paleocene time. Oil and gas accumulations are the best known result of the tectonic environment. Mineral deposits, particularly uranium, appear to be closely related to structural conditions in the area. End_of_Article - Last_Page 788------------