Title

Geochemical characteristics of naturally acid and alkaline saline lakes in southern Western Australia

Abstract

Abundant shallow saline lakes on the Archean Yilgarn Craton in southern Western Australia exhibit a rare spectrum of geochemical conditions. Here the field geochemistry over three seasons (pH, salinity, and temperature), as well as major ions, trace elements, and H, O, and S stable isotopes of surface waters and shallow groundwaters from 59 ephemeral lakes in southern Western Australia (WA) are reported. Approximately 40% of the lakes and 84% of the measured groundwaters in WA are extremely acidic (pH < 4) and pHs are observed as low as 1.7. The salinity of lake waters and groundwaters ranges from rare freshwaters to common saline waters and brines with total dissolved solids >28%. The fluids are typically Na–Cl to Na–Mg–Cl–SO4 brines with variable yet locally high amounts of Ca, K, Al, Fe, Si, and Br. The acid brine fluid compositions are unusual. For example, in some fluids the amount of Al≫Ca, the amount of Br > K, and comparison of total S to

Date of this Version

2009

DOI

http://dx.doi.org/10.1016/j.apgeochem.2008.11.013

Volume

24

Issue

2

Pages

268-284

Link Out to Full Text

http://www.sciencedirect.com/science/article/pii/S0883292708004034