|
|||||
|
|
Source of coesite inclusions within inherited magmatic zircon from Sulu UHP rocks, eastern China, and their bearing for fluid–rock interaction and SHRIMP dating |
|
| Authors: | Z M ZHANG H-P SCHERTL J L WANG K SHEN J G LIOU |
| Institution: | Institute of Geology, Chinese Academy of Geological Sciences, No. 26, Baiwanzhuang Road, Beijing 100037, China (); State Key Laboratory of Geological Processes and Mineral Resources, China University of Geosciences, Wuhan 430074, China; Institut für Geologie, Mineralogie und Geophysik, Ruhr-Universität Bochum, D-44780 Bochum, Germany; Shandong Institute and Laboratory of Geological Sciences, Jinan 250013, China; Departments of Geological and Environmental Sciences, Stanford University, Stanford, CA 94305, USA |
| Abstract: | The 5-km deep Chinese Continental Scientific Drilling Main Hole penetrated a sequence of ultrahigh pressure (UHP)-metamorphic rocks consisting mainly of eclogite, gneiss and garnet-peridotite with minor schist and quartzite. Zircon separates taken from thin layers of schist and gneiss within eclogite were investigated. Cathodoluminescence images of zircon grains show that they have oscillatory zoned magmatic cores and unzoned to patchy zoned metamorphic rims. Zircon rims contain rare coesite and calcite inclusions whereas cores contain inclusions of both low- P minerals (e.g. feldspar, biotite and quartz) and coesite and other eclogite-facies minerals such as phengite and jadeite. The zircon cores give highly variable |
| Keywords: | UHP metamorphism fluid–rock interaction alteration zircon U–Pb dating Dabie-Sulu orogen |