Studies of geology and hydrology in the basin and range province, Southwestern United States, for isolation of high-level radioactive waste characterization of the Trans-Pecos region, Texas

The Trans-Pecos region of Texas, in the southeasternmost part of the Basin and Range province is reported on. It is semiarid; precipitation ranges from less than 250 to 450 millimeters and potential evapotranspiration is as great as 2.5 Meters annually. Structurally, the region is transitional with the Great Plains to the east; only the northern and western parts of the region have well-developed northwest-trending basins and ranges. The area has experienced repeated deformation since the Precambrian with igneous activity and basin-and-range extension, and to a lesser extent Laramide structures, dominating the topography. Potential host media for isolation of high-level radioactive waste in the region include: intrusive rocks occurring as stocks, sills, and laccoliths of several rock types; tuffaceous rocks, which include densely welded ash-flow tuff; basaltic lava flows; and argillaceous rocks. Quaternary tectonism of the regin is characterized.