Ground water is an important natural resource in the Gulf of Mexico region. Although the region as a whole is relatively rich in water resources, water availability and quality vary dramatically throughout the area. Water resources include rivers—the Chattahoochee, Alabama, Mississippi, Sabine, Trinity, Brazos, Colorado, Rio Grande, and Grijalva—and the immense groundwater resources that are the focus of this chapter. Many major cities in the Gulf of Mexico basin (e.g., Miami, in Florida; Memphis, in Tennessee; Gulfport and Baton Rouge, in Louisiana; and Houston and San Antonio, in Texas) rely chiefly on ground water. Climate varies from moist temperature or subtropical to semiarid conditions, and while population densities (and water-resource demands) vary from minimal to intense, it can be stated that fresh, potable water is the mineral resource in greatest demand. Its continued availability in the region will require special attention in the near future. As elsewhere, the foremost challenge is the provision of adequate quantities of good-quality water, but several special problems exist in the region, including salt-water intrusion and subsidence. An understanding of the hydrogeologic setting of aquifers in the Gulf of Mexico basin is required to preserve and fully utilize this valuable resource.
Aquifers in the Gulf of Mexico basin area (Fig. 1) may be grouped into the following categories: clastic sediments dipping toward the center of the basin; the major carbonate systems of Florida, Texas, and Yucatan; and less importantly, major alluvial aquifers, island aquifers, and volcanic aquifers.
The thick section of predominantly Cenozoic clastic sediments
Figures & Tables
The Gulf of Mexico Basin
Eighteen chapters deal with the entire Gulf of Mexico basin. Included are significant contributions from Mexican geologists. Nine topical chapters cover regional aspects of physiography and bathymetry, structural framework, the basement crust, salt tectonics and listric faulting, igneous activity, seismic stratigraphy, oil and gas resources, mineral resources and geopressured-geothermal energy, and ground water. Six chapters summarize regional stratigraphy and paleogeography for the pre-Triassic, Triassic-Jurassic, Lower Cretaceous, Upper Cretaceous, Cenozoic, and late Quaternary. Also included is a synthesis of the origin and development of the Gulf of Mexico basin. Six 4-color plates summarize the bathymetry, natural resources, tectonics, and basement structure and subcrop of the region, and provide a stratigraphic correlation chart and geologic cross sections.