Aqueous Environmental Geochemistry

Laboratory simulations of Mars aqueous geochemistry

We report on laboratory experiments in which we allowed an SNC-derived mineral mix to react with pure water under a simulated Mars atmosphere for 7 months. These experiments were performed at one bar and at three different temperatures in order to simulate the subsurface conditions that most likely exist where liquid water and rock interact on Mars today. The dominant cations dissolved in the s...

Urban environmental geochemistry of trace metals.

As the world's urban population continues to grow, it becomes increasingly imperative to understand the dynamic interactions between human activities and the urban environment. The development of urban environmental geochemistry has yielded a significant volume of scientific information about geochemical phenomena found uniquely in the urban environment, such as the distribution, dispersion, an...

Basic Concepts in Environmental Geochemistry of Sulfidic Mine-Waste Management

An Overview of Isotope Geochemistry in Environmental Studies

Isotopes of many elements have been used in terrestrial, atmospheric, and aqueous environmental studies, providing powerful tracers and rate monitors. Short-lived nuclides that can be used to measure time are continuously produced from nuclear reactions involving cosmic rays, both within the atmosphere and exposed surfaces, and from decay of long-lived isotopes. Nuclear activities have produced...

Calcium isotope fractionation between aqueous compounds relevant to low-temperature geochemistry, biology and medicine

Stable Ca isotopes are fractionated between bones, urine and blood of animals and between soils, roots and leaves of plants by >1000 ppm for the 44Ca/40Ca ratio. These isotopic variations have important implications to understand Ca transport and fluxes in living organisms; however, the mechanisms of isotopic fractionation are unclear. Here we present ab initio calculations for the isotopic fra...