Aqueous Geochemistry II

Abstract

Abstract This chapter presents a more quantitative understanding of the sources and controls on the chemical composition of natural waters than provided in Chapter 2. Much of this understanding has been gained using various modeling approaches. After a perspective gained from observational data, the chapter considers a simple relationship developed more than 50 years ago to explain trends in major ion distributions in natural waters. The chapter then examines stoichiometric and reactor-based models for more quantitative analyses. Silicate minerals are the ultimate source of most inorganic ions in natural waters, and the authors examine the kinetics and mechanisms of mineral weathering. Finally, the chapter considers the types of inferences and understanding of the factors that control the chemical composition of natural waters that we can learn from stable isotope abundances in solutes and from studies using large data sets covering broad spatial scales and various ranges of temporal scales.