Galveston Island, Bolivar Peninsula (a land-tied island) and associated tidal deltas together comprise a sand-barrier feature separating the Gulf of Mexico from Galveston Bay, East Bay, and West Bay, Texas. This composite sand mass extends parallel with the shoreline from Caplan on the east to San Luis Pass on the west, a distance of 50 miles. The barrier feature is the easternmost part of a line of barriers, which is interrupted at only a few places by river deltas and extends a distance of more than 600 miles along the Texas and Mexican coasts.

The sand body below Galveston Island is approximately 30 miles long, 30 feet thick, and averages about 1½ miles wide. It thins to zero near the 30-foot contour, 2 miles seaward of the gulf shore and a few hundred feet landward of the bay shore. Eolian processes increase the thickness of barrier island sand masses along the south Texas coast by as much as 40 feet.

Geological processes producing barrier island and other shoreline sand bodies throughout the world during the Recent standing sea-level stage have produced similar sand bodies in standing sea-level stages of the geologic past. It seems logical that lenticular barrier island sands probably form reservoir rocks containing large quantities of hydrocarbons in both structural and stratigraphic traps in many sedimentary basins. Several examples have been described in the literature. Many accumulations of the stratigraphic type remain to be found and there is a real need for criteria for their recognition and for the prediction of their location. The paper summarizes the geologic processes, setting (framework), history, genesis, lithologic character and sequence, directional features, shape, and trend of the Galveston barrier island sand mass and related facies. The model should be of value to a geologist in the exploration for and exploitation of reservoirs of this type.

End_of_Article - Last_Page 2519------------