These cross sections numerically correspond to previously published onshore cross sections (CS0002--Dodge and Posey, 1981) and extend those sections across the continental shelf into the Miocene, a recent target of renewed petroleum exploration.

Variable intensity of diagenesis is the factor primarily responsible for contrasting regional reservoir quality of Tertiary sandstones from the upper and lower Texas coast.

The publication comprises 24 structural dip cross sections, spaced 15 to 20 mi apart along the Texas coast, and 4 structural strike cross sections. Dip sections extend from near the Wilcox outcrop to the coastline.

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.

Mapping based on Landsat imagery was initiated along the Texas coast for four test sites selected for contrasting vegetation, environmental geology, and levels of economic development.

The State-owned submerged lands of Texas encompass nearly 6,000 square miles (15,540 km²) and extend from Mexico to Louisiana. The area includes the bays, estuaries, and lagoons, as well as the inner continental shelf 10.3 miles (16.6 km) seaward of the Gulf shoreline (fig. 1).

The land surface in the Texas Coastal Zone is interlaced with active and potentially active surface faults. They are subtle features which are difficult to identify until they have caused damage to manmade structures. To date (1978), significant damage has resulted.

Aquifers in the Houston-Galveston area are composed principally of fluvial-deltaic sediments. The Alta Loma Sand is a complexly faulted, high-sand-percent unit that represents a seaward progression of fluvial, delta-plain, and delta-front facies.

Reservoir quality of lower Teritary sandstone reservoirs along the Texas Gulf Coast is controlled by sandstone depositional environment, mineralogical composition, and consolidation history (compaction, cementation, and leaching).

Sequential shoreline monitoring, using vintage chans and aerial photographs, documents temporal and spatial variations in historical Gulf shoreline changes.