Coesite in eclogite from the North Qaidam Mountains and its implications |
| |
Authors: | Zhang JianXin Meng FanCong Li JinPing Mattinson CG |
| |
Institution: | (1) Insitutite of Geology, Chinese Academy of Geological Sciences, Beijing, 100037, China;(2) Department of Geological Sciences, Central Washington University, 400 E. University Way, Ellensburg, WA 98926, USA |
| |
Abstract: | Coesite provides direct evidence for ultrahigh pressure metamorphism. Although coesite has been found as inclusions in zircon
in paragneiss of the north Qaidam Mountains, it has never been identified in eclogite. In this contribution, based on petrographic
observations and in situ Raman microprobe spectroscopy, coesite was identified as inclusions in garnet of eclogite from the Aercituoshan, Dulan UHP
metamorphic unit, north Qaidam Mountains. Coesite is partly replaced by quartz, showing a palisade texture. This is the first
report on coesite in eclogite from the north Qaidam Mountains, and is also supported by garnet-omphacite-phengite geothermobarometry
(2.7–3.25 GPa, 670–730°C). Coesite and its pseudomorphs have not been found in eclogites and associated rocks of other units
of the north Qaidam Mountains. Further studies are required to confirm if all metamorphic units in the north Qaidam Mountains
underwent the ultrahigh-pressure metamorphism.
Supported by National Natural Science Foundation of China (Grant Nos.41772138, 40472102 and 40272095), Program of Excellent
Young Scientists of the Ministry of Land and Resources of China, and Geological Survey Project of China Geological Survey
(Grant No. 1212010611811) |
| |
Keywords: | North Qaidam Mountains Dulan eclogite coesite Ultrahigh pressure metamorphism |
本文献已被 SpringerLink 等数据库收录! |
| 点击此处可从《中国科学通报(英文版)》浏览原始摘要信息 |
| 点击此处可从《中国科学通报(英文版)》下载免费的PDF全文 |
|