Date of Award
Earth and Environmental Sciences
Dr. Ron Stoessell
Dr. Mark Kulp
Dr. Ioannis Georgiou
Accumulations of brackish groundwater exist across south Louisiana within the shallow, south-dipping Pleistocene to Upper Miocene Baton Rouge Aquifer System (BRAS). This research investigates the source of brackish groundwater through geochemical analysis of representative groundwater samples by comparing the following geochemical ratios along with other trace elements. Low Bromide (Br)/Chloride (Cl) and Potassium (K) /Cl ratios, high Sodium (Na) /Cl ratios, trace Magnesium (Mg) concentrations, and low Strontium (Sr) 87/Sr86 in brackish waters from the BRAS are inconsistent with in situ saline water from marine formation fluids of similar age. The ratios are consistent with in situ saline-water sources from Lower Miocene or Paleogene formation fluids from dissolved recrystallized halite. Deep formation fluids have interacted with Louann Salt diapirs underlying the BRAS area, dissolving halite, and are shown to have moved up fault planes and entered shallow aquifers to mix with the in situ groundwaters.
Prochaska, Lesley C., "Geochemical Evidence for Vertical Migration of Deep Formation Fluids through the Baton Rouge -Denham Springs Fault System" (2012). University of New Orleans Theses and Dissertations. 1561.