EARLY JURASSIC BANJING INTRUSIVE COMPLEX OF SOUTHERN MARGINAL ZONE OF NORTH CHINA BLOCK,XUZHOU

Abstract

The south margin zone of North China block would be transformed into an active belt in the period of collision between Yangtze block and North China Block. Banjing intrusive complex intruded in Xuzhou-Suzhou arcuate tectonic belt at the postorogenic of early Jurassic. w ( 40 Ar)/ w ( 39 Ar) platean age of hornblende from quartz monzodiorite is (191.3±0.5) Ma. The instrusive body is consisted mainly of dioritic rocks showing the geochemical characters of calc-alkalic andesite and accompany with minor of alkali gabbro The magma derived from decompressional partial melting of tholeiitic lower crust under extensional condition. The paired magma-gold mineralizational belt in southern margin of North China block is consisted of calc-alkalic rocks from Banjing and high potassic rocks from Tongshi of western Shandong uplift and their associated gold mineralization.