Tectonics and Sedimentation Along Antler Orogenic Belt of Central Nevada: ABSTRACT

Abstract

The Antler orogenic belt of central Nevada is a zone of tectonic activity which profoundly affected sedimentation patterns during the late Paleozoic. Lower Paleozoic through Middle Devonian strata indicate deposition in miogeosynclinal to eugeosynclinal environments with deposition of carbonate rocks on the east and shale, chert, and volcanic rocks on the west. In Late Devonian time, the depositional sequence was interrupted by eastward thrusting of the Roberts Mountains system which carried siliceous eugeosynclinal sediments onto miogeosynclinal carbonate rocks in the Antler belt. Debris eroded and transported eastward from this thrust system overwhelmed carbonate deposition during latest Devonian and earliest Mississippian time. Early Mississippian through Early Pennsyl anian tectonism with a strong vertical component provided a source terrane which again shed coarse to fine detritus eastward. These synorogenic sediments are herein interpreted as having been deposited in a shallow-marine and marginal-marine environment although carbonate rocks were at times deposited. This interpretation differs significantly from others that interpret the rocks as deepwater flysch deposits. As tectonism slowed, carbonate deposition recurred in central Nevada and the Antler belt was overlapped by Lower Permian sediments. With the overlap, shelf-to-basin sedimentation similar to that of the early Paleozoic was resumed. Antler tectonism is thus interpreted as having interrupted a well-established depositional system which persisted in a fragmentary manner throughout the t me of deformation, and which finally was reestablished across the deformed zone. End_of_Article - Last_Page 738------------