安徽省庐江县泥河铁矿床地质特征及成因分析

泥河铁硫矿床位于长江中下游成矿带内庐枞盆地的西北部,矿床中铁、硫储量均达到大型矿床规模,硬石膏储量达到中型规模,是长江中下游成矿带内近年来重大找矿突破之一,其发现具有重要的理论意义和勘探价值.泥河矿区内主要地层为砖桥组和双庙组安山质火山熔岩和碎屑岩,侵入岩体主要为辉石闪长玢岩.磁铁矿体呈厚大的透镜状分布于闪长玢岩穹窿顶...

Geological Characteristics and Genesis of Nihe Iron Deposit

The Nihe iron deposit, adjacect to the Tanlu fault, is located in the northwest margin of the Luzong Mesozoic volcanic basin, and is only three kilometers away from the Luohe iron deposit in the southwest. The Nihe iron deposit is a concealed deposit with multi-mineral resources, consisting of one large-scale magnetite ore deposit, one large-scale magnetite-pyrite ore deposit and one medium-scale anhydrite ore deposit. The magnetite ore bodies are situated in the south-west of the deposit, and are layer like or lenticular, occurring in the top of the intrusive dome that caused by the emplacement of pyroxene diorite-porphyrite in the Zhuanqiao formation during late Jurassic. The magnetite-pyrite ore bodies are situated in the north-east of the deposit, with two different occurrences, either in the pyroxene diorite-porphyrite body formed coevally with iron ore body, or in the volcanic rocks of the lower segment of the Zhuanqiao formation relating to strata. The anhydrite ore bodies are situated in the middle of the deposit, occurring as lens in the volcanic rocks of the lower segment of the Zhuanqiao formation. Ore types are so complex that the magnetite ore can be divided into eight natural types, while the magnetite-pyrite ore with five natural types. There are more than 40 minerals in the deposit, and the iron is rich in sulfur and phosphorus, but for the useful ore compositions of Fe, S and anhydrite, there are also other beneficial or harmful compositions in the ore, such as P, V, Ti, Cu, Zn, and so on. Within the Nihe iron deposit, there are intense alterations of the host rocks, and the alterations are widespread and variable, with obvious regularity such as transverse stratification and vertical zonality. In which, the anhydrite pyroxenitization is the most important alteration near the ore. The deposit type is similar to the Taocun-type in Nanjing-Wuhu district, and thus the genesis belongs to porphyrite-type.