The Van Horn Mountains caldera is a small (~10-km2) igneous center in the Trans-Pecos volcanic province. The caldera formed 37 to 38 mya during eruption of the first of two ash-flow tuffs related to the caldera.

This folded transparent map is at the same scale as its corresponding Geologic Atlas of Texas (GAT) sheet and can be superimposed on it to compare gravity information with surface geology.

The Upper Cretaceous Olmos Formation in South Texas continues to be an active exploration target 60 years after oil was first discovered in this clastic assemblage. The shallow, oil-bearing formation was deposited on a broad, wave-influenced shelf. Sand accumulated in two depocenters.

This folded transparent map is at the same scale as its corresponding Geologic Atlas of Texas (GAT) sheet and can be superimposed on it to compare gravity information with surface geology.

The Big Wells (San Miguel) reservoir in Dimmit and Zavala Counties, South Texas, produces from a broadly lenticular, wave-dominated deltaic sandstone encased in prodelta and shelf mudstones.

This folded transparent map is at the same scale as its corresponding Geologic Atlas of Texas (GAT) sheet and can be superimposed on it to compare gravity information with surface geology.

The wide variability in structural styles within the growth-faulted, geopressured trends of the Texas Gulf Coast is illustrated by detailed structural maps of selected areas of the Wilcox and Frio growth-fault trends and quantified by statistical analysis of fault compartment geometries.

This folded transparent map is at the same scale as its corresponding Geologic Atlas of Texas (GAT) sheet and can be superimposed on it to compare gravity information with surface geology.

Numerous salt-emission areas exist within the Permian outcrop in the Rolling Plains of Texas and southwestern Oklahoma. Sodium chloride waters underlie the area at relatively shallow depths, discharge from salt springs and salt seeps, and greatly impair the quality of ground and surface waters.

The San Andres Formation in the Palo Duro Basin is a middle Permian carbonate-evaporite sequence situated between two red-bed units, the underlying Glorieta and the overlying undifferentiated Queen-Grayburg sequences.