ECLOGITIZED METAGRANITOID FROM THE SU-LU ULTRA-HIGH PRESSURE (UHP) PROVINCE, EASTERN CHINA

Lenses of weakly deformed metagranitoid and coesite-bearing eclogite are both found within mylonitic orthogneiss of the Jiaodong Group in the Su-Lu ultra-high pressure (UHP) province, eastern China. In the metagranitoid, omphacite overgrowing host clinopyroxene, and garnet coronas developed along the grain boundaries between igneous plagioclase and mafic phases suggest that the metagranitoid suffered an eclogite facies metamorphism. Quartz aggregates after igneous quartz in the metagranitoid show a distinctive polycrystalline, granoblastic texture. This texture is similar to quartz aggregates of the Dora-Maira metagranite which suffered coesite-eclogite facies metamorphism, but is dissimilar to the Mount Mucrone metagranite which recrystallized under the less extreme quartz eclogite facies. These features of the Su-Lu metagranitoid suggest that the UHP metamorphism may have affected not only the eclogite but also the surrounding metagranitoid.