Oct 31, 2014 · A total of 32 whole-rock samples were analysed by X-ray fluorescence spectrometry (XRF) for major and trace elements. Samples were cut into 10–15 cm 3 blocks, washed in distilled water and dried prior to crushing in a steel jaw crusher and powdering in an agate ball mill at the University of Cambridge, UK. Fused glass discs and pressed powder