About This Item

Share This Item

The AAPG/Datapages Combined Publications Database

Utah Geological Association

Abstract


Cenozoic Geology of Western Utah: Sites for Precious Metal and Hydrocarbon Accumulations, 1987
Pages 271-278

Late Cenozoic Drainage History of the Northern Markagunt Plateau, Utah

John J. Anderson

Abstract

The manner in which numerous streams in the southern High Plateaus of Utah in places follow courses that are structurally controlled whereas elsewhere they flow transverse to structure makes it clear that their courses are not everywhere consequent. Bear Creek, tributary to the Sevier River and the major drainage line of the north-central Markagunt Plateau, is a case in point. Not only does Bear Creek execute an abrupt right-angle turn to leave the structurally closed Bear Valley graben within which it rises, but it also flows across a structural high within this graben. This course is explained as the result of a combination of superposition and stream piracy.

Distinctive gravel deposits found in upland areas of the Markagunt Plateau indicate that the intermontane valleys of this area once were filled with upper Tertiary alluvial deposits eroded from the upfaulted High Plateaus. Bear Creek came into being once this fill reached a level where drainage could find its way out of the Bear Valley graben. Originally Bear Creek flowed northward to join westward-flowing drainage into the Great Basin, but in time an eastward-flowing tributary to the Sevier River eroded headward to capture Bear Creek. Either prior to or after this capture, downcutting superposed Bear Creek across the structural high in the Bear Valley graben.

It is possible that a similar history of superposition can explain the seemingly anomolous course of the Sevier River where it flows transverse to structure in Circleville Canyon and Marysvale Canyon.


Pay-Per-View Purchase Options

The article is available through a document delivery service. Explain these Purchase Options.

Watermarked PDF Document: $14
Open PDF Document: $24