Synchrotron radiation X-ray diffraction in situ study of fine-grained minerals in shock veins of Suizhou meteorite

摘要

The synchrotron radiation X-ray diffraction technique developed for in situ study at high pressure and temperature has also been used to investigate microscopic mineral inclusions in ultrahigh-pressure metamorphic rocks and deep-mantle samples. Present study added two more examples of successful utilization of synchrotron radiation X-ray diffraction technique for in situ investigations of fine-grained (0.5—30 μm in size) minerals in very thin shock melt veins of the Suizhou meteorite: (ⅰ) X-ray diffraction measurement of extremely small-sized vein matrix minerals, and (ⅱ) identification of the micron-sized new mineral tuite embedded in the vein matrix. It has been revealed that the fine-grained vein matrix consists of well crystallized garnet, kama-cite and troilite, and the powder diffraction pattern consisting of 17 lines with d-values, intensities (I), relative intensities (I/I_o) and Miller indices, as well as the cell parameters for the new mineral tuite has also been successfully obtained. The result of present investigations has enriched the content of dynamic high-pressure mineralogy and that of Earth's mantle geochemistry.