Three closely spaced oblique-slip faults displace a Quaternary gravel and sand unit overlying Eocene Claiborne strata in the Trinity River Valley, Leon County.

For the past decade, geologists at the Bureau of Economic Geology, The University of Texas at Austin, have prepared various maps of the Texas Coastal Zone.

Secondary leached porosity is common to dominant in near surface to deep subsurface lower Tertiary sandstone reservoirs along the Texas Gulf Coast. This secondary porosity is in the form of leached feldspar grains, volcanic rock fragments, carbonate cements, and carbonate-replaced grains.

Lignite development will place major demands on ground-water supplies.

Five distinct facies are recognized in the Eocene Queen City exposures between the Trinity River valley and the Louisiana state boundary. These facies (fluvial, deltaic, tidal flat, barrier, and tidal delta) display diagnostic suites of physical and biogenic structures.

The Texas Coastal Plain is ideal for studying physical processes and the late Quaternary sedimentological record.

The suitability of salt domes in the east Texas basin (Tyler basin), Texas, for long-term isolation of nuclear wastes is being evaluated. The major issues concern hydrogeologic and tectonic stability of the domes and potential natural resources in the basin.

The Catahoula Formation is composed of ancient fluvial sediments that controlled a wide range of water/sediment interactions responsible for uranium mobilization, transportation, and concentration.

Sediments of the Texas inner shelf are generally fine grained; coarse clasts ( > 0.5 mm) are uncommon (< 1%) over much of the area. Higher concentrations of coarse material, however, occur in discrete areas that apparently represent positions of foyer deltas.