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.
","abstract_html":"<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) <sup>87</sup>/Sr<sup>86</sup> 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>","abstract_has_math":false,"creators":["Prochaska, Lesley C"],"institution":null,"degree_name":"M.S.","degree_level":"Thesis","degree_discipline":"Earth and Environmental Sciences","degree_department":null,"school":null,"contributors":["Dr. Ron Stoessell","Dr. Mark Kulp","Dr. Ioannis Georgiou"],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2012,"date_issued":"2012-12-15T08:00:00Z","date_published":"2012-12-15T08:00:00Z","updated_at":"2026-07-24T05:29:36Z","subjects":["Geochemistry, Baton Rouge Aquifer, Fault System, Halite, Strontium, Louann Salt","Geochemistry","Geology"],"languages":[],"rights":[],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"https://scholarworks.uno.edu/td/1561","outbound_label":"Repository record","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Dr. Ron Stoessell","Dr. Mark Kulp","Dr. Ioannis Georgiou"]},{"key":"dc:creator","label":"Author","values":["Prochaska, Lesley C"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"thesis:degree_discipline","label":"Discipline","values":["Earth and Environmental Sciences"]},{"key":"thesis:degree_level","label":"Degree Level","values":["Thesis"]},{"key":"thesis:degree_name","label":"Degree Name","values":["M.S."]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["Geochemistry, Baton Rouge Aquifer, Fault System, Halite, Strontium, Louann Salt","Geochemistry","Geology"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["https://scholarworks.uno.edu/td/1561"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["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.
"]},{"key":"dc:title","label":"Title","values":["Geochemical Evidence for Vertical Migration of Deep Formation Fluids through the Baton Rouge -Denham Springs Fault System"]}]}],"canonical_facts":{"dc:contributor":["Dr. Ron Stoessell","Dr. Mark Kulp","Dr. Ioannis Georgiou"],"dc:creator":["Prochaska, Lesley C"],"dc:description.abstract":["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.
"],"dc:identifier":["https://scholarworks.uno.edu/td/1561"],"dc:subject":["Geochemistry, Baton Rouge Aquifer, Fault System, Halite, Strontium, Louann Salt","Geochemistry","Geology"],"dc:title":["Geochemical Evidence for Vertical Migration of Deep Formation Fluids through the Baton Rouge -Denham Springs Fault System"],"thesis:degree_discipline":["Earth and Environmental Sciences"],"thesis:degree_level":["Thesis"],"thesis:degree_name":["M.S."]},"updated_at":"2026-07-24T05:29:36Z"}