ABSTRACT: Influence Of Tectonics and Eustasy on Fluvial Architecture, Upper Cretaceous Strata of the Kaiparowits Plateau, South-Central Utah

LITTLE, WILLIAM W., University of Colorado, Boulder, CO

Middle Coniacian through Paleocene(?) strata of the Kaiparowits Plateau of south-central Utah make up a nearly 2-km-thick sequence of principally fluvial deposits represented by the John Henry and Drip Tank members of the Straight Cliffs Formation, and the Wahweap, Kaiparowits, Canaan Peak, and Pine Hollow formations. With the exception of the Straight Cliffs Formation, which contains significant coal reserves, this sequence has received little attention in the past, yet these units hold an abundance of information pertaining to Late Cretaceous tectonic and eustatic history. Deposition occurred in a variety of fluvial environments, including gravelly braided, sandy braided, mixed-load meandering, coarse-grained meandering, tidally-influenced meandering, and anastomosing stream systems Vertical changes in fluvial style appear to be cyclic in nature, and are the result of changing conditions in the Kaiparowits basin brought about by the interaction of active tectonism in the Sevier and Laramide deformation belts and large-scale fluctuations in Late Cretaceous eustatic sea level. Fluvial architectural analysis can be used to construct two- and three-dimensional models for individual units within each of these formations. A comparison of architectural models for successive units can be used to study the affects of eustasy, basin subsidence, and source area tectonics on the evolution of fluvial systems.

AAPG Search and Discovery Article #91017©1992 AAPG Rocky Mountain Section Meeting, Casper, Wyoming, September 13-16, 1992 (2009)