Full Title: Warren Hamilton Field Trip: The West Texas Nexus: Orogeny, Magmatism, K-Pg Boundary, Vertebrate Biostratigraphy, and Chihuahuan Desert Geohydrology
Endorsed by: GSA’s Planetary Geology, Mineralogy, Geochemistry, Petrology, and Volcanology, Structural Geology and Tectonics, Geochronology Divisions
Led by: Jesse Kelsch, Thomas Shiller, Patricia W. Dickerson, Joe Satterfield, Kevin Urbanczyk, Elizabeth Koeman-Shields
Date: Tue–Sat. 14-18 Oct. 2025
Time: 2 p.m. (first day)-5:30 p.m. (last day)
Location: Begins in Midland, Texas, USA
CEUs: 4.0
Big Bend structures, strata and waters record >500 Ma of Earth history. On this trip we'll visit: Paleozoic strata of the Marathon Basin; the Marathon fold-thrust belt recording Pangea assembly; Early Cretaceous marine platform carbonates; Late Cretaceous megafauna (Alamosaurus & Quetzalcoatlus); the K-Pg boundary; Laramide contractional structures of the Terlingua Uplift and the Sierra del Carmen; some of the 48-18 Ma Trans-Pecos magmatic province, including calderas, lavas, ignimbrites, pluton-associated mercury mineralization, and the Solitario lacco-caldera; Rio Grande rift structures with exposed kinematic history; and the Rio Grande/ Rio Bravo, plus springs from cross-border aquifers. Cost includes transportation (full size SUVs), Riata Inn in Marfa for 10/14 (double occupancy), Chisos Mining Co in Terlingua for 10/15-16 (double occupancy), Marathon Motel in Marathon for 10/17 (double occupancy), meals, snacks, and water. Students can apply for the Warren Hamilton Fund to defer the cost of the trip.
Because of the remote location and different stops, some participants may start at the closest airport in Midland, TX, while some may arrive in Marfa, TX. Trip leaders will transport those arriving in Midland to the field-trip start in Marfa on the afternoon of October 14 and will describe Davis Mountains volcanism on the drive. Dinner and lodging are provided for the night of October 14 in Marfa regardless of how the participants arrive. All participants leave for the field tour together from Marfa on Wednesday morning, October 15. On each day, light hiking will be part of the field trip to reach certain outcrops, with optional longer hikes for those who want them. Bathroom stops during driving tours will range from vault toilets at state and national park rest areas, to shrubs and boulders. Many opportunities for private toilets will be available each day. Our caravan will drive through one U.S. Customs and Border Protection checkpoint, for which participants will require appropriate legal resident or immigration documents. Mornings and evenings will probably be chilly but above freezing temperatures, while days are likely to be warm to hot. Layers of field clothing, including hiking shoes and sun protection, are recommended.
By purchasing this item, you are buying a seat on an in-person geological field trip.
Please review these Field Safety Documents. You will be contacted to provide your consent to these forms after purchasing a field trip.
Learn more about this and other GSA Connects 2025 events.
For additional information, please contact Rebecca Taormina, rtaormina@geosociety.org, GSA Field Trip and Short Program Coordinator.
Product Code: FT25CN425
Product Category: FTRIP