Supplementary materials for thesis "Provenance studies of British prehistoric greenstone implements using non-destructive analytical methods" - part 5

Geochemical data obtained using field-portable non-destructive X-ray fluorescence instrumentation (PXRF), supported by magnetic susceptibility (MS) measurements, is able to narrow the provenance of IPC Group I prehistoric greenstone axes to two locations in West Cornwall: St Ives and Mullion Island. It also supports the provenance of IPC Group III axes to a greenstone quarry near Perranuthnoe, Cornwall and supports the Cornish origin of seven Irish gabbroic and doleritic axes. Provenancing methodology involved the examination of 149 axe and 73 greenstone thin sections, followed by comparison of 272 axe and over 100 exposure geochemical and magnetic analyses using Simple Component Analysis (SCA), element discrimination diagrams, Discriminant Analysis (DA) and comparative statistics (MANOVA, West). Accuracy, precision and detection limits of the PXRF are determined using international reference samples, greenstone samples and greenstone axes. PXRF instrumentation is generally linearly calibrated with zero offset, and with a compensatable bias for K, Ca, Ti, Mn, Fe, Rb, Sr, Y, Zr, Nb, Ba, Ce and Pb. Precision in measuring greenstone rock composition is 5.3% relative standard deviation of the mean based on two PXRF measurements and from elements with concentrations tentimes the PXRF detection limit (generally less than 900ppm. for major elements and less than 30ppm for trace elements). Empirical studies using newly manufactured greenstone axes show that no adjustments to PXRF measurements are required when measuring polished curved axe surfaces, and that Ti, Y, Zr and Nb PXRF measurements made on weathered surfaces are statistically indistinguishable from those measured on fresh, flat surfaces of the same composition. KT5 magnetic susceptibility meter precision is 1.5% relative when measuring typical greenstone rock with MS of 0.6 x 10^-3 SI. A robust correction procedure based on estimates of axe curvature, surface relief and dimensions is shown to correct the measured MS to that of the true rock value.This is number 5 of 5 parts. The PCD images have been converted to JPG to enable accessibility. For details of how to open the original PCD files please refer to the README file.For more information, please refer to the thesis.

本数据集包含使用现场便携式无损X射线荧光仪（X-ray fluorescence，PXRF）获取的地球化学数据，并辅以磁化率（magnetic susceptibility，MS）测量，可将IPC第一组史前绿石斧的物源限定在康沃尔西部的两处地点：圣艾夫斯（St Ives）与马利恩岛（Mullion Island）。同时，该数据支持将IPC第三组斧具的物源追溯至康沃尔佩兰努斯诺附近的绿石采石场，并证实了7件在爱尔兰发现的辉长岩与辉绿岩斧具的康沃尔起源。
本研究的物源溯源方法涵盖对149件斧具及73件绿石薄片样品的镜下观察，随后通过简单组分分析（Simple Component Analysis，SCA）、元素判别图、判别分析（Discriminant Analysis，DA）以及比较统计学方法（多变量方差分析，MANOVA，West），对比了272件斧具与逾100处露头的地球化学及磁化率分析数据。
研究通过国际参考样品、绿石标准样品及绿石斧具，确定了PXRF的准确度、精密度与检出限。PXRF仪器通常采用零偏移线性校准，且对钾（K）、钙（Ca）、钛（Ti）、锰（Mn）、铁（Fe）、铷（Rb）、锶（Sr）、钇（Y）、锆（Zr）、铌（Nb）、钡（Ba）、铈（Ce）及铅（Pb）存在可补偿的系统偏差。基于两次PXRF测量，且元素浓度为PXRF检出限10倍以上（主量元素通常低于900ppm，微量元素低于30ppm），绿石岩石成分测量的相对标准偏差精密度为5.3%。
针对新制备的绿石斧具开展的实证研究表明，在测量抛光弧形斧面时无需对PXRF的测量结果进行校正；且在风化表面上测得的Ti、Y、Zr及Nb的PXRF数据，与相同成分的新鲜平整表面的测量结果在统计学上无显著差异。KT5型磁化率仪在测量磁化率为0.6×10^-3 SI的典型绿石样品时，相对精密度为1.5%。本研究提出了基于斧具曲率、表面起伏与尺寸的稳健校正流程，可将实测磁化率校正为真实岩石的磁化率值。
本内容为5个部分中的第5部分。为提升可访问性，已将PCD格式图像转换为JPEG格式。如需了解原始PCD文件的打开方法，请参阅README文件。更多详细信息请参阅该学位论文。