Provenance Analysis of Permian (Guadalupian) Deposits: Implications for Sediment Routing and Stratal Geometry, Delaware Basin, TX

Abstract

The Paleozoic Permian Basin includes the western Delaware Basin and eastern Midland Basin. These basins, separated by the northwest-trending Central Basin Platform, are located along the Pangean suture zone, where sediment source areas and the sediment-routing history are pivotal factors controlling oil and gas reservoir distribution and quality. Basin formation and fill history are related to the Ouachita-Marathon orogeny, the Pennsylvanian-Permian mountain building event as a result of the collision of Gondwana and Laurentia along the southern North American margin. Long-standing interpretations have concluded that the majority of siliciclastic input to the Delaware Basin during middle Permian (Guadalupian) time was sourced from the Ancestral Rocky Mountains (ARM) of central Laurentia. Here, we perform an integrated detrital zircon geochronologic and petrographic provenance analysis of the Leonardian-Guadalupian strata found in the Glass Mountains, located adjacent to the terminal thrust belt of the Marathon orogeny to test the dominant source of Permian siliciclastic deposits of the southern Delaware Basin. We isolate core and rim ages of the detrital zircons using LA-ICP-MS at the University of Texas at Austin Geo-Thermochronometry Lab. A core age indicates initial crystallization age, whereas a rim age can be used to track recycling of the zircon through subsequent crystallization. We identified eight groups of core-rim ages, which correspond to distinct provinces of Laurentian, Gondwanan, Rodinian, Pan-African and Amazonian sediment source areas. However, there is a conspicuous absence of Paleoproterozoic ARM core-rim ages. This is likely a result of the proximity of the Glass Mountains to the southern margin of the Delaware Basin, and uplifts of the Ouachita-Marathon fold-thrust belt. Therefore, the data from the Glass Mountains represent a reference for a southern signature of sediment supply and routing from mountainous source areas to depositional sinks during Guadalupian time. We find a similar age signature across the Delaware Basin, which suggests that southern source areas are more important to sediment delivery than previously thought. Knowledge of a proximal, southern source area for the siliciclastic sediment filling the Delaware Basin during Pennsylvanian to Permian time contributes to our understanding of depositional evolution and the potential importance of proximal, high-relief source areas to sediment delivery in the Permian Basin.

AAPG Datapages/Search and Discovery Article #90323 ©2018 AAPG Annual Convention and Exhibition, Salt Lake City, Utah, May 20-23, 2018