CHARACTERIZATION OF MINERAL SPRINGS AND SOURCE LOCALITY IN THE NORTHEASTERN LLANO UPLIFT REGION, CENTRAL TEXAS

Mineral springs with high concentrations of hydrogen sulfide (H₂S) gas located in Central Texas (counties of Burnet, San Saba and Lampasas) were characterized based on chemical constituency, surrounding lithology, and hydrogen sulfide content. The main discharge points studied were “Sulphur Spring” along the Colorado River, “Sulfur Springs” in Burnet County, “Hancock Spring,” “Hannah Spring,” “Gooch Spring,” and “Cooper Spring” in Lampasas, Texas. Particularly high amounts of dissolved solids, a high specific conductance, slightly acidic conditions, and minor thermal elevation were observed at each of the H₂S bearing springs. This was in contrast to the same measurement criteria taken among the various freshwater springs located in close proximity to the H₂S bearing springs.

Additionally, a source locality for the H₂S was studied in reference to a possible hydrothermal source or a biological mediated series of red-ox reactions. Another possible source is the potential relationship of Ordovician-Pennsylvanian carbonate reservoirs to local faulting processes associated with the Bend Arch and the down-warping of the Fort Worth Basin, formed during the early stages of the Ouachita Structural Belt. The source of sulfate associated with the mineralized springs is theorized to be associated with reduction of sulfides in the Central Texas Lead District; current research is focusing on delineating source and migration of fluids in the region.