安徽沿江地区岩浆岩的深部构造信息

DEEP TECTONIC INFORMATION OF MAGMATIC ROCKS ALONG THE YANGTZE RIVER IN ANHUI

本区分布着十分广泛的中生代岩浆岩，根据岩浆岩的物质组成、岩石组合、地壳结构、成矿作用及Ｎｄ、Ｓｒ、Ｐｂ同位素组成与比值变化等特征，可划分出３个岩浆岩带。在内带发育幔源型碱性玄武岩浆演化系列的基性—中酸性侵入岩，伴生有矽卡岩型Ｃｕ、Ｆｅ、Ｓ、Ａｕ矿床。北外带以中酸性侵入岩为主，属于下地壳重熔产物。南外带以Ｓ型花岗岩为主，显示出由上地壳重熔的特点。南、北两带均为钙碱性演化系列，并伴生斑岩型铜矿床。

Mesozoic magmatic rocks are widespread along the Yangtze River in Anhui. According to the composition of the magmatic rocks, rock associations, deep crustal structure, mineralization and Nd, Sr and Pb isotopic compositions and ratios, three magmatic belts may be distinguished. In the inner belt, there are mantle derived basic to intermediate acid intrusive rocks resulting from the evolution of alkaline basaltic magmas, in which there occur skarn Cu, Fe, S and Au deposits. In the north outer belt, intermediate acid intrusive rocks predominate, belonging to the product of the anatexis of the lower crust. The south outer belt is dominated by S type granite, showing the features of the anatexis of the upper crust. The south and north belts are both marked by calc alkaline series, in which porphyry Cu deposits occur.