Synchrotron data of Ryan Petra III (May 2015) - As incorporation in apatite Quick XANES

Spatially resolved chemical speciation by determination of the oxidation state using X-ray absorption spectroscopy is a powerful tool to explore and understand processes in a number of fields such as geology, material science, catalysis or biology. Using the fluorescence signal, speciation at trace element concentrations becomes feasible. Probing the chemical state at distinct spots or regions of interest rapidly and repeatedly using fast X-ray absorption spectroscopy provides an ideal means to study in-situ processes or beam-sensitive samples. An example of the importance of visualizing of the distribution of the oxidation state of a trace element in a geologic application is the distribution of the As oxidation state in arsenic-bearing apatite, which is found in iron-oxide, copper, gold deposits in the Mt Isa inlier. Tracing the origin of chemical zoning and interpreting it in terms of fluid-rock interaction is fundamental to understanding how metals are transported and deposited in these minerals. Further, 3d elements provide a means to understand the behavior of pathfinder elements in resistate minerals associated wit gold mineralization, for example by studying the relationship between the substitution of Ti in rutile with M3+ (such as V) and M5,6+ species (such as W and V) and the variation of the oxidation state of vanadium around the mineralized zones in gold deposits. These experiments will set the stage for fast XANES and EXAFS measurements using the Maia detector providing valuable information about geological mineralization processes. The aim is to investigate different fast scanning XANES methods, varying the order of the XYE axes. We will apply 2D XANES mapping using the energy as the fast scanning axis to map the distribution of oxidation state in geological thin sections. These will provide vital clues to understand mineralization and alteration processes and how metals are transported and deposited in minerals, and the factors that drive indicator elements in path finder minerals to Gold deposits.