Natural occurrence of reidite in the Xiuyan crater of China
Article first published online: 1 APR 2013
© The Meteoritical Society, 2013.
Meteoritics & Planetary Science
Volume 48, Issue 5, pages 796–805, May 2013
How to Cite
Chen, M., Yin, F., Li, X., Xie, X., Xiao, W. and Tan, D. (2013), Natural occurrence of reidite in the Xiuyan crater of China. Meteoritics & Planetary Science, 48: 796–805. doi: 10.1111/maps.12106
- Issue published online: 13 MAY 2013
- Article first published online: 1 APR 2013
- Manuscript Accepted: 19 FEB 2013
- Manuscript Received: 8 JAN 2013
- NNSF of China. Grant Number: 41172044
- GIG CAS 135 Project. Grant Number: Y234071001
The high-pressure minerals of reidite and coesite have been identified in the moderately shock-metamorphosed gneiss (shock stage II, 35–45 GPa) and the strongly shock-metamorphosed gneiss (shock stage III, 45–55 GPa), respectively, from the polymict breccias of the Xiuyan crater, a simple impact structure 1.8 km in diameter in China. Reidite in the shock stage II gneiss displays lamellar textures developed in parental grains of zircon. The phase transformation of zircon to reidite likely corresponds to a martensitic mechanism. No coesite is found in the reidite-bearing gneiss. The shock stage III gneiss contains abundant coesite, but no reidite is identified in the rock. Coesite occurs as acicular, dendritic, and spherulitic crystals characteristic of crystallization from shock-produced silica melt. Zircon in the rock is mostly recrystallized. The postshock temperature in the shock stage III gneiss is too high for the preservation of reidite, whereas reidite survives in the shock stage II gneiss because of relatively low postshock temperature. Reidite does not occur together with coesite because of difference in shock-induced temperature between the shock stage II gneiss and the shock stage III gneiss.