Structural features of Brenham salt dome, Washington and Austin counties, Texas

The Brenham salt dome, located in the center of the Texas Gulf Coastal Plain, and discovered prior to 1915 by the drilling of a shallow water well, is a typical piercement dome, shown by the 2,950-foot uplift of the Crockett formation. The maximum thickness of cap rock is 722 feet. The thinnest section encountered is on the east side of the dome, where an 89-foot section of cap rock was drilled before the salt was encountered. The greatest amount of uplift occurs at this point and the thin cap suggests that a section of several hundred feet was eroded before deposition of the Crockett. Wells drilled on and around this structure have been discouraging as to possible super-cap, cap-rock, and flank production.