A MEGABRECCIA WITH ASSOCIATED STRATIGRAPHY OF THE CHERRY CANYON AND BELL CANYON FORMATIONS TRANSITION (GUADALUPIAN, MIDDLE PERMIAN), SOUTHERN DELAWARE MOUNTAINS, WEST TEXAS

Abstract

The Cherry Canyon and Bell Canyon Formations (Guadalupian, Middle Permian) are well exposed in the southern part of the Delaware Mountains, West Texas and are marked by the presence of several distinct and widespread debris flows. Various lithostratigraphic units (members) of these two formations were originally named for exposures in the Guadalupe Mountains and the northern part of the Delaware Mountains, West Texas. These units are not easily recognized litho-stratigraphically in the southern part of the Delaware Mountains, but some correlations can be made by using biostratigraphic methods. One of the easily recognizable debris flows in the southern Delaware Mountains is a megabreccia named the B-debris that is well exposed in a road cut along Texas FM road 2185 about 25 miles from a bird's eye view to the northeast of Van Horn and can be traced to the northwest into the southern part of the Delaware Mountains where it is extensively exposed. The first objective of this study was to map the lateral extent of the B-debris flow that may be traced along the upper parts of the ridges in the 42 sq. mi study area. The second objective was to describe the litho- and biofacies of a well exposed stratigraphic section, named the WP-section, of the Cherry Canyon and Bell Canyon Formations transition, and is capped by the B-debris. The WP-section appears to include the upper part of the Cherry Canyon and lower part of the Bell Canyon Formations. This study discusses the exposed lateral extent of the B-debris from Texas FM road 2185 to the north-northwest into the southern part of the Delaware Mountains.