GEOLOGIC MAPPING FOR THE TEXAS STATEMAP PROGRAM

Geologic mapping for the Texas STATEMAP program has been conducted in critical aquifer recharge areas, urban and rural corridors experiencing population growth, and areas having specific environmental and natural resource concerns. Maps have been constructed at scales of 1:24,000 and 1:100,000. Some maps are available in a digital, Geographic Information System (GIS) format. Examples of map products and related information for parts of west and central Texas and the Texas Gulf Coast will be presented. Aquifer-related study areas include the Edwards aquifer's San Antonio and northern segments, Hill Country Trinity aquifer, Brazos alluvial aquifer, Seymour alluvial aquifer, and Hueco Bolson aquifer. Much of the Edwards and Hill Country Trinity aquifers coincide with urban and rural corridors undergoing population growth west and north of San Antonio and north of Austin. Study areas along the international border with Mexico include El Paso and Del Rio. Texas coastal areas studied include the Galveston and Mustang Island regions. Geologic maps of the study areas provide data that support responsible decision-making regarding use of land and natural resources. These maps provide basic stratigraphic and structural information for the geologic framework of areas to aid in managing water resources and planning land-use, identifying aquifer recharge areas, identifying sources of aggregate and other earth resources, recognizing stratigraphic units prone to foundation problems, and evaluating changes in sensitive coastal environments.