Evidence for vertical movement of diagenetic fluids, Texas Gulf Coast

Both the study of burial diagenesis and the study of present-day formation waters of Jurassic through Pleistocene formations from the Texas Gulf Coast document local vertical fluid transport of at least several kilometers. Evidence includes the following: (1) discharge at the land surface of Mesozoic-derived brines as bad water; (2) emplacement of Mississippi Valley-type lead-zinc mineralization by fluids derived from Mesozoic formations in salt dome cap rocks at or near the land surface; (3) emplacement of uranium in Tertiary aquifers as a result of reduction by ascending reduced sulfur, presumably of Mesozoic origin; (4) emplacement of calcite cement derived from Mesozoic strata Tertiary sandstones; and (5) presence of fluids in Plio-Pleistocene rocks with chemical signatures that could only have been derived from Mesozoic strata. Material-transport calculations indicate that the volumes of fluid involved far exceed the volume of connate water deposited in the basin, strongly suggesting some mechanism of thermally driven convective flow