The Antler orogeny occurred in the Mississippian passive margin of the sialic North American continent in Nevada and probably in Idaho (Speed and Sleep, 1982). Speed and Sleep (1982) proposed an Arc-continent collision model for the Antler orogeny. In their model they assume that The Roberts Mountain Allochthon formed as a result of the large accretionary prism underthrusted by the continental slope and outershelf. The vertical loading and downflexing of the continental shelf by the allochthon formed the Antler foreland basin. Speed and Sleep (1982) advocated that the Island arc collision model is matched with regional geologic characteristics of the orogeny, and answers the question, how the oceanic strata can thrust about 4 km. In addition,
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This enclaved region formed by the post Antler tectonism including: Late Paleozoic deformation, uplift and removal of some parts of the Roberts mountain allochthon; emplacement of the Golconda allochthon over Roberts Mountain allochthon; Jurassic and Cretaceous of the Cordilleran fold and thrust belt; and Cenozoic Basin and Range Tectonism. Speed and Sleep (1982) focused on the enclaved region to support the Arc-collision hypothesis, and they believed that within this enclaved region (1) Antler related rocks slightly changed from their Mississippian positions compare to the subjacent Paleozoic shelf rocks. (2) The eastern limit of the lower Paleozoic oceanic rocks is the approximate trace of the Roberts mountains thrust, and (3) if a regional Mesozoic decollement extends from eastern to western Nevada, it lies deeply within or below the Paleozoic shelf succession. In addition, the position and extent of the Antler orogeny is uncertain outside the central …show more content…
The North American source of terrigenous sediments in allochthon are sound, whereas there is no persuasive reason to suggest accumulation only in the Paleozoic continental margin. The sediments of the Roberts mountains autochthon consist of calcareous strata of Cambrian through Devonian age; these rocks deposited on the shelf of the North American continent. In general, the Antler age deformation in the Roberts Mountains autochthon is almost absent, except some minor deformation seems to have been due to shear transmitted by a surface thrust rather than intracontinental
This enclaved region formed by the post Antler tectonism including: Late Paleozoic deformation, uplift and removal of some parts of the Roberts mountain allochthon; emplacement of the Golconda allochthon over Roberts Mountain allochthon; Jurassic and Cretaceous of the Cordilleran fold and thrust belt; and Cenozoic Basin and Range Tectonism. Speed and Sleep (1982) focused on the enclaved region to support the Arc-collision hypothesis, and they believed that within this enclaved region (1) Antler related rocks slightly changed from their Mississippian positions compare to the subjacent Paleozoic shelf rocks. (2) The eastern limit of the lower Paleozoic oceanic rocks is the approximate trace of the Roberts mountains thrust, and (3) if a regional Mesozoic decollement extends from eastern to western Nevada, it lies deeply within or below the Paleozoic shelf succession. In addition, the position and extent of the Antler orogeny is uncertain outside the central …show more content…
The North American source of terrigenous sediments in allochthon are sound, whereas there is no persuasive reason to suggest accumulation only in the Paleozoic continental margin. The sediments of the Roberts mountains autochthon consist of calcareous strata of Cambrian through Devonian age; these rocks deposited on the shelf of the North American continent. In general, the Antler age deformation in the Roberts Mountains autochthon is almost absent, except some minor deformation seems to have been due to shear transmitted by a surface thrust rather than intracontinental