鄂东地区早三叠世中晚期沉积特征

鄂东地区早三叠世中晚期为潮间带上部、潮上带以及萨布哈沉积环境。以前有人认为:(1)燕山期岩浆岩是控制大冶式铁铜(金银钴硫)矿床生成的内因,围岩条件是控制矿床生成的外因;(2)不同时代的地层控制着不同种类矿化的丰度,围岩性质的差异制约着矿化的强度。统计表明,80％以上的铁、铜、钼矿储量与潮间带上部、潮上带及萨布哈相的大冶群第四至第七段(T_1dy~(4-7)碳酸盐岩关系密切;黄石—广济(今武穴市)一带的铅锌矿与泻湖相的第三至第五段(T_1dy~(3-5)碳酸盐岩关系密切。

SEDIMENTARY CHARACTERISTICS OF THE EAST HUBEI REGION DURING THE MIDDLE AND LATE EARLY TRIASSIC

The middle and late Early Triassic sedimentary environments in eastern Hubei include the upper part of intertidal zone, supratidal zone and sabkha, where a succession of the dolomite-bearing carbonate rocks, namely the main ore-forming country rocks of the Daye-type iron and copper deposits etc. were deposited. The present paper deals in detail with sedimentary characteristics of the carbonate rocks according to sectional structures, rock types, sedimentary structures and geochemical characteristics, and finally, the relationship between lithology and mineralization is also discussed.