EVIDENCE FOR EPISODIC BASIN DEWATERING IN SALT-DOME CAP ROCKS

In two Gulf Coast salt domes, brines were intermittently expelled from geopressured zones deep in the stratigraphic section and were channeled upward along escape structures bounding the salt diapirs. Overhanging anhydrite cap rock helped to focus some escaping fluid into the zone of dissolution between the top of salt and overlying residual anhydrite cap rock. Paleomagnetic data from the Winnfield salt dome suggest that sulfide-producing basin-dewatering events and anhydrite cap-rock accumulation occurred between 157 and 145 Ma. -from Authors