Major Element Chemical Heterogeneity in Geo2 Olivine Microbeam Reference Material: A Spatial Approach to Quantifying Heterogeneity in Primary Reference Materials
Major Element Chemical Heterogeneity in Geo2 Olivine Microbeam Reference Material: A Spatial Approach to Quantifying Heterogeneity in Primary Reference Materials
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DOI：
10.1111/ggr.12134
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发表时间：
2017-03
影响因子：
3.8
通讯作者：
M. Pankhurst;R. Walshaw;D. Morgan
中科院分区：
文献类型：
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作者：
M. Pankhurst;R. Walshaw;D. Morgan
一项270个点的分析研究在一个大型的（约。1200 μm × 1200 μm）的Geo2橄榄石芯片（P and H Developments，Standards for EPMA），显示FeO丰度的相对范围为8.7%。依次测量不同分辨率的交错和重叠网格，以证明空间模式不是由于漂移或其他外部误差源造成的。使用商业上可获得的地理信息系统软件对结果进行绘图和插值，以便能够根据位置高精度地预测成分。观察到的简单、系统的分带模式表明，某些元素确实存在可接受均匀性的有用大小区域。这种知识允许用户将已表征芯片的各个区域作为目标，以用作不同的测量标准。随着分析时间的减少和数据集的增长，这种方法可以通过表征大芯片和延长传统块重新抛光和涂覆之间的时间来最大限度地提高实验室效率，特别是在避免先前光束损坏是关键问题的情况下。
A 270 spot‐analysis study was conducted across a large (ca. 1200 μm × 1200 μm) chip of Geo2 olivine from a commercially available GEO Mk2 block (P and H Developments , Standards for EPMA), which revealed an 8.7% relative range in FeO abundance. Interleaved and overlapping grids of different resolutions were measured sequentially to prove spatial patterns are not due to drift or other external sources of error. Results were mapped and interpolated using commercially available geographical information system software, such that composition could be predicted according to location with high accuracy. The simple, systematic zonation pattern observed demonstrates that useful‐sized regions of acceptable homogeneity do exist for some elements. This knowledge allows a user to target individual regions of a characterised chip for use as distinct measurement standards. As analysis times decrease and data sets grow, this approach may maximise laboratory efficiency by characterising large chips and extending time between conventional block repolish and coating, particularly in those cases where the avoidance of prior beam damage is a key concern.