XANES studies at the Al K-edge of aluminium-rich surface phases in the soil environment

Aluminum is highly abundant in the Earth's crust where it is present in a wide variety of primary and secondary aluminosilicate minerals, amorphous phases, and aqueous solution species. The speciation and coordination of AI in many of these phases, particularly those that are X-ray amorphous or present as thin surface coatings, are often unknown or based on indirect methods. We have utilized aluminum K-edge XANES in a study of the nature of several such phases, specifically the aluminum rich phases present in soils on the surfaces of quartz and feldspar grains in loess, and aluminum substitution in iron oxyhydroxides.