Examination of porosity and permeability (reservoir quality) data, as determined by whole core, acoustic log, and petrographic analyses of lower Tertiary sandstones along the Texas Gulf Coast, made it possible to delineate areas most favorable for development of hydrocarbon reservoirs.

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.