Watershed geochemistry: The control of aqueous solutions by soil materials in a small watershed

Laboratory and field data indicate that the aqueous geochemistry of a small watershed in siliceous materials is largely determined by reactions between soil and water. For dissolved SiO2, Ca+2, K+, Na+, a reversible steady state is achieved in the soil within hours. The solute concentrations are in equilibrium with kaolinite, the end-product in the local weathering sequence. The processes occur in a drainage basin in which solution activities are the predominant form of erosion.