Eclogite occurrences in the southern Tianshan high-pressure belt, Xinjiang, western China

Eclogite pods and layers of eclogites in mafic blueschists are the most pro minent witnesses of eclogite facies metamorphism in the southern Tianshan h igh-pressure belt of Western China. The P-T evolution was deciphered in ord er to understand the geotectonic framework of these rocks. Geothermobaromet ric evaluation for matrix assemblages reveals peak metamorphic condition be tween 14 and 21 kbar at 500 to 600 degrees C. Prograde growth zoning and mi neral inclusions in garnet are evidence for a clockwise P-T path. The prese nce of intimate eclogite/metabasic blueschist interlayering and the high P- T estimates suggest that the eclogite-facies rocks from the southern Tiansh an high-pressure belt formed in a tectonic regime similar to the Franciscan type. Therefore the southern Tianshan high-pressure belt is most important in order to resolve the Paleozoic tectonic evolution of central Asia.