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.

Fractures and veins in strata of the Palo Duro Basin area, Texas Panhandle and eastern New Mexico, are characterized using data from outcrop and core studies and from fracture identification log analysis.

Statistical analysis of chemical data on Texas Eocene coals revealed startigraphic and geographic trends in lignite quality. Chemical data on near-surface coals wre obtained from various private and public sources. Seams from deep-basin coals were compared.

Fluid pressure, permeability, rates and patterns of ground-water flow, and chemical and isotopic composition of ground water in carbonate rock in the lower part of the San Andres Formation (Permian) in eastern New Mexico and the Texas Panhandle were studied to characterize the origin and movement of brine within an evaporite-carbonate-shale conf

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.