江南隆起带皖赣相邻区燕山期岩浆岩Nd-Sr同位素特征

江南隆起带皖南地区与赣东北地区燕山期岩浆岩Nd-Sr同位素特征的对比研究表明,皖南燕山期花岗岩体、斑岩体及赣东北燕山期花岗岩与赣东北燕山期斑岩体在成岩物质来源上具有明显差异。皖南燕山期花岗岩和斑岩体及赣东北燕山期花岗岩成岩物质以壳源为主,成岩物质来源区夹有一定的幔源物质,而赣东北燕山期斑岩体则具有幔源特征,这是赣东北地区燕山期与岩浆岩有关的多金属矿床发育、而皖南地区不发育的重要原因。Nd-Sr同位素的研究结果与地球物理、成岩构造背景和稀土元素等研究结果相吻合。

CHARACTERISTICS OF Nd-Sr ISOTOPES OF THE YANSHANIAN MAGMATIC ROCKS IN THE JIANGNAN RISE BORDERING ANHUI AND JIANGXI PROVINCES

The characteristics of Nd-Sr isotopes of the Yanshanian magmatic rocks, distributed in the southern part of Anhui province and northeastern part of Jiangxi province, and tectonically attached to the Jiangnan Rise, were studied in the paper. The results showed that the Yanshanian granitoids and granitic porphyries in southern Anhui and the Yanshanian granitoids in northeastern Jiangxi came mainly from the crust, and the source area included some mantle matters. The Yanshanian granitic porphyries in northeastern Jiangxi had a characteristics of mantle source-type. So the polymetal deposits which related to the Yanshanian magmatic rocks in northeastern Jiangxi were developed better than those in southern Anhui. The research results of Nd-Sr isotopes were confirmed by the studies of geophysical survey,metallogenetic tectonic setting, basement tectonics and rare earth elements at the same time.