Geochemical Evidence for Vertical Migration of Deep Formation Fluids through the Baton Rouge -Denham Springs Fault System

<p>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 <em>in situ</em> saline water from marine formation fluids of similar age. The ratios are consistent with <em>in situ</em> 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 <em>in situ</em> groundwaters.</p>

Name thesis:degree_name

M.S.

Level thesis:degree_level

Thesis

Discipline thesis:degree_discipline

Earth and Environmental Sciences

Year

2012

Author dc:creator

• Prochaska, Lesley C

Contributors dc:contributor

• Dr. Ron Stoessell
• Dr. Mark Kulp
• Dr. Ioannis Georgiou

• Geochemistry, Baton Rouge Aquifer, Fault System, Halite, Strontium, Louann Salt
• Geochemistry
• Geology

Repository record dc:identifier

https://scholarworks.uno.edu/td/1561

OAI identifier oai:identifier

oai:scholarworks.uno.edu:td-2514