ZHAO Ling-hao1,2, QIU Hua-ning1, YUN Jian-bing1, HU Rong-guo1, WANG Min1
(1. Key Laboratory of Isotope Geochronology and Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou510640, China;
2. Graduate School of Chinese Academy of Sciences,Beijing100049, China)
Abstract: Garnet-clinopyroxene(Gt-Cpx) geothermometer is very important in constrain of the p-t conditions of the ultrahigh pressure eclogites. Several Gt-Cpx temperature formulas and Fe2+ adjustments for omphacite have been applied. Light- colored and dark-colored eclogites from Bixiling, eastern Dabieshan, were investigated withabove methods. Charge balance for Fe2+ in omphacite(Droop,1987) and the formula of Ravna(2000) are mostly suitable for light-colored eclogite, but not for the dark-colored one. Based on our calculation in this study, the ultrahigh-pressure metamorphism of the Bixiling eclogite took place at the p-t conditions of 3～3.4GPa and 660～731℃.
Key words: Gt-Cpx geothermometer;Fe2+ adjustments; omphacite;eclogite;Bixiling
E-mail: qiuhn@gig.ac.cn
ACTA MINERALOGICA SINICA Vol. 30, No. 3, 2010, Page 283-292
