South-Central Section - 49th Annual Meeting (19–20 March 2015)

Paper No. 1
Presentation Time: 8:05 AM

PROVENANCE OF THE MIDDLE PERMIAN, DELAWARE MOUNTAIN GROUP, DELAWARE BASIN, WEST TEXAS AND SOUTHEAST NEW MEXICO


ANTHONY Jr., John M., School of Geology, Energy, and the Environment, Texas Christian University, 2950 West Bowie Street, TCU Box 298830, Fort Worth, TX 76107 and XIE, Xiangyang, School of Geology, Energy, and the Environment, Texas Christian University, Fort Worth, TX 76107, j.m.anthony@tcu.edu

The siliciclastic strata of the Middle Permian (Guadalupian), Delaware Mountain Group of the Delaware basin, located in west Texas and southeast New Mexico have long been interpreted to record deep marine deposition that were pre-sorted by eolian processes. However, the provenance of the Delaware Mountain Group siliciclastic strata is still debated. The majority of previous researchers have suggested the crystalline basement uplifts of the Ancestral Rocky Mountains as the primary source for the Delaware Mountain Group due to the observed arkosic-subarkosic mineralogy. This study combines point-count data of 54 thin sections from the three formations that comprise the Delaware Mountain Group (Bell Canyon, Cherry Canyon, and Brushy Canyon) and U-Pb detrital zircon geochronology analyses from four subsurface whole core samples of the Delaware Mountain Group to shed further light on the potential source terranes delivering siliciclastics to the Delaware basin during the middle Permian. Samples exhibit the commonly observed arkosic-subarkosic mineralogy associated with an Ancestral Rocky Mountain source which is characterized by the potential of supplying fist-cycle arkosic material to the Delaware basin; however results of four detrital zircon geochronology samples disagree with previous interpretations. All samples show three predominant age peaks, including Paleozoic (300-500 Ma), Neoproterozoic (545-790 Ma), and Mesoproterozoic (950-1200Ma). Previous regional geochronology studies suggest that Paleozoic age peak can be correlated with the Appalachian orogeny, Neoproterozoic age peak is likely derived from Suwanee terrane, and the Mesoproterozoic age peak is related the Grenville orogeny. All samples possess a minor percentage of late Paleoproterozoic ages (1600-1800 Ma) which are indicative of an Ancestral Rocky Mountain source. New data from this study suggest that the Ancestral Rocky Mountains were not a major contributor of siliciclastic sediment to the Delaware basin during the middle Permian.