Discovery of eclogite inclusions and its geological significance in early Jurassic intrusive complex in Xuzhounorthern Anhui,eastern China

The early Jurassic intrusive complex is chieflymade of monzodioritic porphyry in northern Anhui andnorthern Jiangsu, which emplaced in 191 Ma. The intrusivecomplexes contain a lot of eclogite inclusions which belong toeclogite and garnet-pyroxenite. The inclusions had under-gone eclogite facies high-pressure metamorphism and am-phibolite facies retrogressive metamorphism. The garnets ineclogite inclusions are mainly almandine varieties and clino-pyroxenes are omphacite and augite. The mineral assem-blage and P-T estimation results show that P-T conditions ofeclogite facies metamorphism and amphibolite facies retro-gressive metamorphism are over 1.2-1.5 GPa, 709-861℃and 0.7-1.03 GPa, 666-738℃, respectively. The discoveryof the high-pressure xenoliths not only is of important sig-nificance to understand the composition and structure ofdeep crust in southern edge of North China Platform, butalso can be of important influence on realizing the subduc-tion-collision-exhumation evolutional process of the Dabie-Sulu ultrahigh-pressure (UHP) metamorphic belt.