PhD student JIAO Shujuan and his teacher GUO Jinghui apply two-feldspar geothermometry to ultrahigh-temperature (UHT) granulites from two localities newly reported in their study (Tuguishan and Xuwujia) and another two localities from previous studies (Dajing/Tuguiwula and Dongpo) in the Khondalite belt..

These results confirm the previous report of extreme metamorphism at Dajing/Tuguiwula and Dongpo, and reveal similar conditions in the new localities studied, suggesting that UHT metamorphism is widespread in the Khondalite belt of the North China craton. Their study demonstrates that UHT metamorphism can be recognized using the two-feldspar geothermometry in rocks that do not possess other key UHT assemblages.

The report has been published on American Mineralogist. Jiao et al. A pplication of the two-feldspar geothermometer to ultrahigh-temperature (UHT) rocks in the Khondalite belt, North China craton and its implications. American Mineralogist,2011,96:250-260（Download here）

Figure. (a) Calculated metamorphic temperatures of the Dajing/Tuguiwula and Dongpo areas. The P-T paths of Santosh et al. (2007a, 2009a) are also shown. (b) Calculated metamorphic temperatures of the Tuguishan and Xuwujia areas. (c) All calculated metamorphic temperatures of the Khondalite belt, North China craton. The KFMASH P-T grid is modified after Kelsey et al. (2004). (Image by JIAO Shujuan)