Geology and Fossils of North Central, Texas (Fort Worth to Mineral Wells)

R. LaRell Nielson, Geology Department,Stephen F Austin State University

The 2021 Texas Academy of Science Geology field trip will be a virtual field trip that you may run at any time. It will have two parts; Part 1 consists of a video discussion of each stop ( ) and Part 2 consists of this field trip guidebook (for use when visiting each of the locations). The field trip will start at Holiday Park, near Benbrook, southwest of Fort Worth, Texas, and will end at the Mineral Wells Fossil Park, west of Minerals Wells, Texas. The locations of the field trip stops are shown on Figures 1 and 2 below.


The area west of Fort Worth, Texas, is an interesting area to visit and collect fossils from strata of both the Cretaceous and Pennsylvanian systems. The Cretaceous strata dip to the east and were deposited on a broad shelf that transitioned from a clastic shelf during the Early Cretaceous to a largely carbonate shelf setting rimmed by the Stewart City Reef. The Pennsylvanian strata were deposited west of the Ouachita fold and thrust belt and dip to the west. These deposits represent a series of large deltas that prograded to the west from the Ouachita mountains into the Fort Worth Basin. The Ouachita Orogeny and subsequent closure of the Rheic Ocean occurred during the Pennsylvanian and Permian periods as North America (“Laurentia”) collided with South America