Discovery of Coesite in the North Qaidam Caledonian Ultrahigh-High Pressure (UHP-HP) Metamorphic Belt in the NE Qinghai-Tibet Plateau

Coesite was discovered as inclusions in zircon separates from paragneiss associated with a large eclogite body in the North Belt of the Qaidam UHP terrane on the Chinese New Year of 2001 by Laser Raman Spectrometer at Tokyo Institute of Technology. Some graphite inclusions also found. However, extensive search did not reveal the occurrence of microdiamond. This finding confirms our previous suggestion that the North Qaidam UHP terrane was recrystallized at P below the diamond stability…