冬瓜山层控夕卡岩型铜矿床成矿流体特征及其成因意义

THE CHARACTERISTICS OF ORE-FORMING FLUID OF DONGGUASHAN STARATA- BOUND SKARN Cu DEPOSIT AND ITS SIGNIFICANCE FOR DEPOSIT GENESIS

对冬瓜山层控夕卡岩型铜矿床的矿物流体包裹体进行了深入研究。结果显示 ,主成矿阶段流体的温度高达 35 0～ 4 0 0℃。成矿流体是一种高温 (35 0～ 4 0 0℃ )、高盐度 (w (NaCl) =13.4 5 %～4 8% )、高密度 (大于 1.1g/cm3 )的流体。其中的稀土元素具轻稀土富集、Eu呈显著负异常、轻重稀土分异明显的特征。由于其特殊的成矿环境 ,流体的输运过程是一种近于等温的过程。成矿作用发生于偏酸性且较还原的条件下。成矿流体由岩浆源和地层共同提供 ,是一个典型多源成矿物质、多成矿阶段。

Comprehensive studies were made for fluid inclusions in minerals of Dongguashan strata-bound skarn deposit. It is demonstrated that the ore forming fluid is a high temperature (350～400℃), high density (larger than 1.1 g/cm 3 ) and high salinity (13.45%～48% NaCl) hydrothermal fluid. The fluid is also characterized by obvious fractionation of REE, enriched in LREE and strong negative Eu anomaly. The ore forming process took place under relative acidic and reductive conditions. The fluid transported as isothermal process under a particularly ore forming environment. It is postulated that the ore forming fluid was suplied by both magmatic and strata sources. The Dongguashan deposit is a typical multi source of ore forming materials, multi ore forming stages and multi controllong factors strata bound skarn deposit.