Ultra high pressure (UHP) metamorphic belt, containing abundant eclogite with lesser amounts of garnet peridotite and gneiss. The paragneiss contains abundant zircon with coesite inclusions whereas the eclogite has garnet with coesite pseudomorphs and omphacite with exsolved quartz. The garnet peridotites are magnesium-rich; olivine in the peridotites is highly magnesian and TiO2-poor and is typical of low-temperature garnet peridotites. The North Qaidam UHP, together with the North Qilian HP belt, about 300 km to the north, constitute a pair of genetically related early Palaeozoic subduction zones along the northern margin of the Tibet Plateau.
Ref.:
- Jingsui Yang, Zhiqin Xu, Shuguang Song, Jianxin Zhang, Cailai Wu, Rendeng Shi, Haibing Li, and Brunel, M. (2001): Discovery of coesite in the North Qaidam Early Palaeozoic ultrahigh pressure (UHP) metamorphic belt, NW China. Comptes rendus de l'Académie des sciences, Série 2: Sciences de la terre et des planètes, 333(11), 719-724 (in English).
- Yang Jingsui, Xu Zhiqin, Zhang Jianxin, Song Shuguang, Wu Cailai, Shi Rendeng, Li Haibing, Liou, J.G., Ernst, G., and Shigenori Maruyama (2001): An early Paleozoic Coesite-bearing HP-UHP metamorphic belt on the northeastern Qinghai-Tibet plateau. UHPM Workshop at Waseda University, AD02, 290-293.
- Yang Jingsui, Xu Zhiqin, Zhang Jianxin, Song Shuguang, Wu Cailai, Shi Rendeng, Li Haibing, and Brunel, M. (2002): Early Palaeozoic North Qaidam UHP metamorphic belt on the north-eastern Tibetan plateau and a paired subduction model. Terra Nova 14 (5), 397–404.
- Shuguang Song, Lifei Zhang, Jing Chen, Liou, J.G., and Yaoling Niu (2005): Sodic amphibole exsolutions in garnet from garnet-peridotite, North Qaidam UHPM belt, NW China: Implications for ultradeep-origin and hydroxyl defects in mantle garnets. American Mineralogist 90, 814-820.
