Data used for developing a composite hydrogeologic framework for inclusion in a geoenvironmental assessment of undiscovered uranium resources in Pliocene- to Pleistocene-age geologic units of the Texas Coastal Plain

A previously completed mineral resources assessment of the Texas Coastal Plain indicated the potential for future discovery of uranium resources. Composite hydrogeologic frameworks can be used in geoenvironmental assessments as a tool to understand potential effects of mining operations. Data for a composite hydrogeologic framework are documented in this data release. The hydrogeologic framework focused on the composite hydrogeologic unit consisting of the upper part of the Miocene-age Fleming Formation/Lagarto Clay, Pliocene-age Goliad and Pleistocene-age Willis Sands, Pleistocene-age Lissie and Beaumont Formations, and Holocene-age alluvial sediments (fluvial alluvium and eolian sand deposits). This composite hydrogeologic unit, which contains the Chicot and Evangeline aquifers of the Gulf Coast aquifer system, is intended for inclusion in a regional-scale geoenvironmental assessment of undiscovered uranium resources where the actual uranium resource is not yet discovered, and therefore the location unknown. The larger work citation that accompanies this data release (Teeple and others, 2022) provides (1) a brief literature review describing the geologic and hydrogeologic settings, (2) the methodology used to develop a composite hydrogeologic framework, and (3) descriptions and maps of the land-surface altitude, composite hydrogeologic unit base and midpoint altitude and depth, water-level altitude, depth of water, unsaturated and saturated zone thickness, and transmissivity and hydraulic conductivity. A composite hydrogeologic unit, created by combining geologic and hydrogeologic data and maps for individual geologic and hydrogeologic units, is intended for use as a tool in a geoenvironmental assessment to evaluate potential contaminant migration through various avenues. Potential applications of the hydrogeologic framework to a geoenvironmental assessment include estimating (1) runoff-flow paths, (2) locations of infiltration, (3) groundwater-flow paths, and (4) rate of transport. Composite hydrogeologic unit properties such as land surface altitude, water-level altitude, depth of water, saturated zone thickness, transmissivity, and hydraulic conductivity provide physical indicators of the potential for transport of contaminants. The procedures outlined in the companion larger work citation (Teeple and others, 2022) provides a method for developing hydrogeologic frameworks that can be applied in other areas where mining may occur.