Synchrotron Data - Cleverley 2230 (Apr 2010) - Mapping the signals of in-situ redox changes during gold precipitation: St Ives, Agnew, Sunrise Dam and Plutonic deposits

Using the unique X-ray Fluorescence Mapping beamline coupled with the Maia-384 detector we plan to map large area (100-500 μm) XANES spectra of important redox species (As, Cr, V and Fe) within the mineral hosts (pyrite, biotite, ilmenite) for naturally occurring hydrothermal gold. This will for the first time allow the spatial determination of a) the coupled changes in redox state of trace elements and allude to the fundamental processes of gold deposition and, b) provide evidence for the redox state of important gold complexes in high grade natural gold deposits.\r\n\r\nWe propose to analyse natural high-grade gold bearing quartz vein material from world-class systems at St Ives, Agnew, Sunrise Dam and Plutonic that have been well characterised by Scanning Electron Microscopy and/or X-ray Fluorescence Mapping (Hough et al, 2009).\nLineage: Data was produced using the Maia 384 element detector array on the XFM X-ray microprobe beamline of the Australian Synchrotron and processed using the GeoPIXE software package.

本研究拟依托独有的X射线荧光成像光束线（X-ray Fluorescence Mapping beamline）结合Maia-384探测器，对天然热液金矿载体矿物（黄铁矿、黑云母、钛铁矿）中关键氧化还原物种（As、Cr、V、Fe）的大面积（100~500 μm）X射线吸收近边结构（X-ray Absorption Near Edge Structure, XANES）光谱开展成像测绘。此项工作将首次实现两项核心目标：a）示踪微量元素氧化还原状态的协同变化，阐明金沉淀的核心地质过程；b）为高品位天然金矿床中重要金配合物的氧化还原状态提供实验依据。

本研究拟分析取自St Ives、Agnew、Sunrise Dam及Plutonic等世界级金矿床的天然高品位含金石英脉样品，此类样品此前已通过扫描电子显微镜（Scanning Electron Microscopy, SEM）和/或X射线荧光成像完成充分表征（Hough等，2009）。

数据溯源：本数据集依托澳大利亚同步辐射装置的XFM X射线微探针光束线，使用Maia 384元素探测器阵列采集数据，并通过GeoPIXE软件包完成后期处理。