Paleozoic evolution and heterogeneity of sediment provenance in the Permian Basin

Abstract

Paleozoic sediment provenance of the Permian Basin remains controversial. This study presents new detrital zircon morphology, UPb ages, and Hf isotope data of eight Paleozoic sandstone samples, and integrates published zircon UPb data in the basin to illustrate the spatial and temporal changes of sediment provenance. The Cambrian sample has predominantly Mesoproterozoic (1500–1300 Ma) grains because of fluvial transport of basement detritus from the local Texas Arch. The Ordovician shoreface sandstone contains mostly rounded grains of Paleoproterozoic (1800–1600 Ma) age, mostly likely by longshore drift reworking detritus from the Transcontinental Arch. The Pennsylvanian sediment provenance shows heterogeneity. While samples from the Northwestern Shelf have both the Mesoproterozoic and Paleoproterozoic groups and low grain roundness, reflecting sediment delivery from basement rocks in the Ancestral Rocky Mountains, a sample in the Midland Basin contains a broad range of ages, including a major Neoproterozoic (800–500 Ma) group that were primarily from peri-Gondwana terranes. The difference suggests that there was limited sediment mixing in the Permian Basin. The similarity of zircon age distributions between the Midland Basin and Fort Worth Basin confirms synorogenic progradation of detritus from the Fort Worth Basin to the Eastern Shelf during the Pennsylvanian. During the early Permian Cisuralian epoch, the compiled UPb data show that the southern and eastern basin contains a significant fraction of Gondwanan detritus, and the amount reduced by the latest Cisuralian as the orogenesis waned. The middle Permian Guadalupian samples on the Northwestern Shelf contain well-rounded grains that are of mainly Grenvillian and Paleozoic ages, suggesting sediment recycling from Laurentia by wind and likely by river as well. The change of sediment provenance from the early to the middle Permian suggests that after the continental collision, Laurentian sediments dominated detritus in the Permian Basin.