Supplementary materials for thesis "Provenance studies of British prehistoric greenstone implements using non-destructive analytical methods" - part 3

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 3 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.

采用便携式非破坏性X射线荧光光谱仪（PXRF）获取的地球化学数据，辅以磁化率（MS）测量，能够将IPC集团I型史前绿松石斧的产地缩小至康沃尔西部两个地点：斯蒂夫尼茨岛和穆利恩岛。此外，该数据亦支持IPC集团III型斧的产地为康沃尔佩兰努斯诺附近的绿松石采石场，并证实了七把爱尔兰玄武岩和辉绿岩斧的康沃尔起源。产地溯源方法涉及对149把斧头和73个绿松石薄片的分析，随后通过简单成分分析（SCA）、元素区分图、判别分析（DA）和比较统计（MANOVA、West）对272把斧头及超过100个暴露的地球化学和磁学分析结果进行比较。PXRF的准确度、精确度和检测限通过国际参考样品、绿松石样品和绿松石斧确定。PXRF仪器通常以零偏移线性校准，并对K、Ca、Ti、Mn、Fe、Rb、Sr、Y、Zr、Nb、Ba、Ce和Pb进行可补偿偏差校准。测量绿松石岩石成分的精度为基于两次PXRF测量的平均值的相对标准偏差5.3%，以及浓度达到PXRF检测限十倍的元素（通常主要元素低于900ppm，微量元素低于30ppm）。使用新制造的绿松石斧进行的经验研究表明，在测量抛光的弯曲斧表面时，无需对PXRF测量进行调整，且在风化表面上进行的Ti、Y、Zr和Nb PXRF测量与在相同成分的新鲜平坦表面上进行的测量在统计学上无显著差异。KT5磁化率计在测量具有0.6 x 10-3 SI磁化率的典型绿松石岩石时的精度为1.5%。基于斧头曲率、表面起伏和尺寸估计的稳健校正程序被证明可校正测量磁化率至真实岩石值。本部分为五部分中的第三部分。PCD图像已转换为JPG格式以方便访问。有关如何打开原始PCD文件，请参阅README文件。更多详情请参考论文。