Abstract

Fossils found in cores from wells in the Midland Basin of West Texas include several kinds of terrestrial plants and a variety of marine animal remains. Depositional settings ranged from basin slope to deep-water basin floor, hence the presence of land plants was unexpected. The fossil plant assemblage is depauperate, dominated by Germaropteris martinsii, a Permian-age peltasperm. Other specimens include the peltasperm Supaia, Sphenopteris germanica, axes of uncertain affinity, and incertae sedis remains presumed to be terrestrial plants. Fossil plants are found predominantly in fine-grained, siliceous mudrocks between coarser-grained calcareous floatstones and wackestones/packstones interpreted as debrites and turbidites, suggesting that the plants were carried from land by surface currents before sinking to the basin floor and being buried by slowly accumulating hemipelagic sediment. Specimens were examined from drill cores in 14 wells spanning an interval from the lower Wolfcamp through the lower Leonard. This record of G. martinsii in lower Permian Wolfcamp rocks is among the earliest occurrences of these plants, which have been found most abundantly in upper Permian strata of Western Europe.