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Full-Text Articles in Physical Sciences and Mathematics

Sedimentology Of Acid Saline Lakes In Southern Western Australia: Newly Described Processes And Products Of An Extreme Environment, Kathleen Counter Benison, Brenda Beitler Bowen, Francisca Oboh-Ikuenobe, Elliot A. Jagniecki, Deidre A. Laclair, Stacy L. Story, Melanie R. Mormile, Boyoung Hong Mar 2007

Sedimentology Of Acid Saline Lakes In Southern Western Australia: Newly Described Processes And Products Of An Extreme Environment, Kathleen Counter Benison, Brenda Beitler Bowen, Francisca Oboh-Ikuenobe, Elliot A. Jagniecki, Deidre A. Laclair, Stacy L. Story, Melanie R. Mormile, Boyoung Hong

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

Naturally acid saline systems with pH values between 1.7 and 4 are common on the Yilgarn Craton of southern Western Australia. a combination of physical and chemical processes here yield a previously undescribed type of modern sedimentary environment. Flooding, evapoconcentration, desiccation, and eolian transport at the surface, as well as influx of acid saline groundwaters, strongly influence these lakes. Halite, gypsum, kaolinite, and iron oxides precipitate from acid hypersaline lake waters. Shallow acid saline groundwaters affect the sediments of the lakes and associated mudflats, sandflats, channels, and dunes by precipitating early diagenetic halite, gypsum, iron oxides, clays, jarosite, and alunite. …


Microbial Growth And Biofilm Formation In Geologic Media Is Detected With Complex Conductivity Measurements, Caroline A. Davis, Estella A. Atekwana, Eliot A. Atekwana, Lee D. Slater, Silvia Rossbach, Melanie R. Mormile Sep 2006

Microbial Growth And Biofilm Formation In Geologic Media Is Detected With Complex Conductivity Measurements, Caroline A. Davis, Estella A. Atekwana, Eliot A. Atekwana, Lee D. Slater, Silvia Rossbach, Melanie R. Mormile

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

Complex conductivity measurements (0.1-1000 Hz) were obtained from biostimulated sand-packed columns to investigate the effect of microbial growth and biofilm formation on the electrical properties of porous media. Microbial growth was verified by direct microbial counts, pH measurements, and environmental scanning electron microscope imaging. Peaks in imaginary (interfacial) conductivity in the biostimulated columns were coincident with peaks in the microbial cell concentrations extracted from sands. However, the real conductivity component showed no discernible relationship to microbial cell concentration. We suggest that the observed dynamic changes in the imaginary conductivity (σ″) arise from the growth and attachment of microbial cells and …