Chemical analysis of a basaltic weathering profile near Exeter, New South Wales, Australia

Soil sustainability implies maintaining the balance between soil erosion and production. While it is known how to assess soil erosion, only recently we have been able to estimate rates of soil and saprolite (namely regolith) production using uranium-series isotopes. This method assesses the time elapsed since rock-forming minerals start fractionating the U-series isotopes. In this study, we assess a sample pre-treatment protocol that has the potential to improve the method used to estimate regolith production rates. We propose that removal (or partial removal) of secondary phases precipitated from solution during pedogenesis (solution-derived phases) and organic matter from regolith may improve the accuracy of this method. This is tested using sequential extraction followed by etching as sample pre-treatment. Here, we assess their effect on the U-series isotopic composition of regolith and infer whether they minimize the presence of solution-derived phases and organic matter. […]