西秦岭礼县—太白地区金、铅锌矿床的地质地球化学

GEOLOGICAL AND GEOCHEMICAL CHARACTERISTICS OF GOLD AND LEAD-ZINC DEPOSITS IN LIXIAN-TAIBAI AREA, WEST QINLING MOUNTAINS

礼县—太白地区的金、铅锌矿床产于泥盆纪沉积盆地。它们都是沉积改造型矿床 ,其含矿建造是中泥盆统或中上泥盆统。根据矿床的地质、地球化学特征 ,该地区的铅锌矿床可以分为 2类 ,厂坝式和邓家山 -八方山式矿床。金矿床可分 3类 ,李坝式、八卦庙式和双王式矿床。厂坝式铅锌矿床产于强变质、弱变形地区 ,属于与变质作用有关的沉积改造型矿床 ;邓家山 -八方山式铅锌矿床产于强变形、弱变质地区 ,属于与构造动力作用有关的沉积改造型矿床。李坝式金矿床是赋存在浊积岩内的微细浸染型金矿床 ;八卦庙式金矿床是产于浅变质细碎屑岩内的石英细脉型金矿床 ;双王式金矿床是产于钠长碳酸盐角砾岩内的微细浸染型金矿床 ,来自上地幔或下地壳的流体和物质参与了这类金矿床的成矿作用。八卦庙式金矿床与邓家山 -八方山式铅锌矿床之间存在成因和密切的空间联系。

Gold and lead\|zinc deposits in Lixian\|Taibai area occur in Devonian sedimentary basin. They are all reformed sedimentary type of deposits. Their ore\|bearing formations are Middle\|Upper Devonian strata. On the basis of geological and geochemical features of ore deposits, the lead\|zinc deposits in this area can be divided into Changba type and Dengjiashan\|Bafangshan type, while gold deposits can be divided into Liba, Baguamiao and Shuangwang types. The Shanghai type lead\|zinc deposits are located in areas of strong metamorphism and weak deformation, thus belonging to the metamorphism\|related sedimentary\|reformed type deposits. The Dengjiashan\|Bafangshan type lead\|zinc deposits are located in areas of strong deformation and weak metamorphism, belonging hence to structural dynamics\|related reformed type. The Liba type gold deposits are micro\|disseminated type gold deposits located in turbidite;the Baguamiao type gold deposits are quartz fine vein type deposits occurring in weakly metamorphic fine\|clastic rock,while the Shuangwang type gold deposits are micro\|disseminated type gold deposits occurring in the albite carbonate breccia, with the fluids and materials from the upper mantle or lower crust taking part in the mineralization. There exists close temporal and spatial relationship between the Baguamiao type gold deposits and the Dengjiashan type lead\|zinc deposits.