PhD student SU Benxun and his teacher ZHANG Hongfu research the detailed mineralogy and mineral chemistry studies of clinopyroxenes from Western Qinling.

The spongy-textured minerals preserve primary shapes and well-defined grain boundaries and do not show apparent interaction with contact minerals or observed melts except the subsequent melts forming melt pockets. The xenocrysts display reactive zoning textureswith host magmas rather than spongy textures.

These observations suggest that melts/host magmas did not play any significant role in the formation of the spongy textures. They therefore propose that spongy-textured clinopyroxenes and spinels in Western Qinling peridotite xenoliths developed from a decompression-induced partial melting event prior to formation of melt pockets and xenolith entrainment in host magmas.

The paper has been published on Contributions to Mineralogy and Petrology. Su et al.The origin of spongy texture in minerals of mantle xenoliths from the Western Qinling, central China. Contributions to Mineralogy and Petrology，2011，161(3): 465-482 （Download Here）

Fig. 1 Back-scattered images of spongy-textured clinopyroxenes and spinels in Western Qinling peridotite xenoliths. (Image by SU Benxun)

Fig. 2 Back-scattered images of spongy-textured clinopyroxenes and their spongy rims in Western Qinling peridotite xenoliths. (Image by SU Benxun)