Epma 1600

X-ray diffraction (XRD) patterns of samples were obtained on PANalytical X’ Pert PRO (PANalytical, Netherlands) by using Cu Kα radiation (λ = 0.15418 nm). The morphologies of the products were observed by the scanning electron microscopy (SEM, Hitachi H-800). The qualitative and semi-quantitative element analysis of the particle sample was tested by using the energy dispersive spectroscopy (EDS, EPMA-1600, Shimadzu Corporation) and X-ray photoelectron spectroscopy (XPS, Axis Ultra, Shimadzu Corporation). The elemental composition of the whole particle was tested by using the atomic absorption spectrometer (AAS, PE-AA400, PerkinElmer Corporation) after dissolving in HNO₃.

Chemical compositions of olivine and clinopyroxene phenocrysts and chrome spinel hosted by olivine were measured by a Shimadzu electron probe microanalyzer (EPMA 1600) at the CAS Key Laboratory of Crust-Mantle Materials and Environments (CA-CMME) of the University of Science and Technology of China (USTC). Back-scattered electron images were used to check the homogeneity of the minerals. During the quantitative analysis of clinopyroxene (cpx) phenocrysts and spinel inclusions in olivine, the operating conditions were the following: 15 kV accelerating voltage, 20 nA beam current and 1 μm spot size. Only the spinel grains located in the central zone of the host olivine phenocrysts were analysed. For olivine, the analytical method described by ref. ^{19 (link)} was used, employing an accelerating voltage of 20 kV, a beam current of 300 nA and a spot size of 5 μm. Natural minerals and synthetic oxides were used as standards, and a programme based on the ZAF procedure was used for all data correction. All the analysed points in cpx phenocrysts were set within thefourier-transform infrared spectroscopy (FTIR) analysis region. Some electron probe micro-analyses (EPMA) of cpx were conducted with a JEOL electron probe microanalyzer in the Hefei University of Technology. Analytical conditions were similar to those used in USTC.