Guadalupe Mountains National Park, TX
September 25, 2019
The geologic mapping group is collaborating with the National Park Service (NPS) Geologic Resources Division to produce geologic maps, cross sections, and reports detailing the geologic resources in Guadalupe Mountains National Park (GUMO), Texas. This is part of the Geologic Resources Evaluation (GRE) program; the goal is to provide a digital geologic map (scale 1:24,000), a geologic resource evaluation report and a geologic bibliography for the park. These products can serve as the foundation for future possible studies focusing on groundwater, geomorphology, soils and geologic hazards in the park, and can be used to communicate geologic information to the public.
The geology of GUMO records marine life in the Delaware Basin during the Permian Period (300-251 million years ago). The Delaware Basin was an arm of the Permian Basin, which covered much of modern southeastern New Mexico and western Texas. Sediment deposition occurred in the Delaware Basin from 265-260 million years ago when it was near the equator and part of the supercontinent Pangea. An extensive reef system, the Capitan Reef, formed in the Delaware Basin. In the park today, rocks record the reef itself (Capitan Limestone), the backreef, forereef, and the deeper basin. Fossils found in the park include sponges, algae, bryozoans, brachiopods, crinoids, fusulinids, trilobites, sea urchins, bivalves, horn corals, ammonoids, nautiloids, and ostracods. Uplift starting 26 million years ago generated steep faults that raised the buried reef material, exposing it to weathering and erosion. Today, the resistant Capitan Limestone forms the park’s signature geologic feature, El Capitan, and the highest peak in Texas, Guadalupe Peak (8751 feet).
References:
Geologic Formations, Guadalupe Mountains National Park, National Park Service, https://www.nps.gov/gumo/learn/nature/geologicformations.htm
KellerLynn, K., G. Bell, L. Carter, A. Poole, and A. Croskrey, 2008, Guadalupe Mountains National Park, Geologic Resources Evaluation Report, Natural Resources Report NPS/NRPC/GRD/NRR-2008/023, NPS D-181.