T269 Paleontology, Paleobiogeography, and Stratigraphy of the Late Cretaceous North American Seas (Posters): A Tribute to Bill Cobban

Wednesday, 3 November 2010
8:00 AM - 6:00 PM
Hall D

SEQUENCE STRATIGRAPHIC FRAMEWORK OF THE CRETACEOUS COX SANDSTONE, INDIO MOUNTAIN, WEST TEXAS

Paper number: T269-7
Program: Technical Sessions
Time: 8:00 AM – 6:00 PM

Authors

Abstract

Indio Mountain represents the North East margin of extensional Chihuahua trough. The excellent exposure of Albian Cox Sandstone offers an ideal opportunity to synthesize sequence stratigraphic framework. The Cox Sandstone is a coastal sequence consisting of interbedded fluvial and shallow marine sandstones and shale. Based on field data and high resolution aerial photo (0.5 m resolution) three sequences of marine to fluvial Transgressive System Tract (TST) overlain by Highstand System Tract (HST) have been identified. The sequences thicken across syndepositional faults and, on a larger scale toward the southwest into the basin.

Detailed measured sections in the Cox Sandstone provide a foundation for characterization of sequences. Each sequence begins with a facies association of shale, siltstone, lenticular fluvial and shoreface sandstones and limestones. Laterally, the sandstones interfinger with shale and eventually pinch out. The upper part of each sequence is characterized by a facies association dominated by fine to medium grained, planar to trough cross-stratified sandstone. In the upper part of the Cox Sandstone, a facies association transitional to the overlying Finlay limestone contains intertonguing marl and cliff forming sandstone. In an upward deepening set of parasequences. Parasequences are well defined within the formation; however abrupt facies changes and syndepositional faults make correlation of individual parasequence difficult over distances of more than 5 km.