皖南大坞尖钨(钼)矿床地质特征及成因分析

Geological characteristics and genesis of the Dawujian tungsten deposit in south Anhui Province

大坞尖钨(钼)矿床是皖南地区新发现的小型钨(钼)矿床。该矿床的矿体主要呈似层状,主要赋存于蓝田组下段白云质灰岩和钙质泥岩中。赋矿围岩以强烈的绢云母化、硅化和碳酸盐化为特征,矿石矿物为白钨矿和辉钼矿,脉石矿物主要有石英和绢云母。矿床的形成可划分4个成矿阶段,即无水矽卡岩阶段、含水矽卡岩阶段、石英硫化物阶段和碳酸盐阶段。通过对矿床地质特征和控矿因素的综合分析研究,认为大坞尖钨(钼)矿床属矽卡岩-云英岩复合型热液矿床,研究区具有重要的找矿潜力。

The Dawujian tungsten deposit is a newly discovered tungsten （molybdenum） deposit, which is located in the transitional zone between the Yangtze Plate and the Cayhaysian（Huanan） Plate. The main ore-body of the Dawujian deposit occurs in a stratiform-like form and is mainly hosted in the do- lomitic limestone and calcareous shale in the Lower Lantian Formation. The wall rocks alteration includes sericitization, silicification and carbonatation. The major ore minerals are scheelite and molybdenite, and the mainly gangue minerals are quartz and sericite. The mineralization of the deposit can be divided into four stages： the anhydrous skarn stage, the hydrous skarn stage, the quartz and sulfide stage and the carbonate stage. Through analysis of the geological characteristics and the ore-controlling factors of the deposit, the Dawujian tungsten deposit is regarded as a skarn-greisen-type deposit, and there is a good potentiality for further exploration of W and Mo deoosits in the study area.