安徽省沙溪斑岩铜矿床成矿流体研究

Research on Metallogenic Fluid of Porphyry Copper Mineral Deposit in Shaxi of Anhui Province

沙溪铜矿床是典型的板内斑岩型矿床,位于安徽省庐江县境内.长江中下游成矿带是我国东部典型的多金属成矿带之一.沙溪矿床是该长江中下游成矿带内目前发现斑岩型铜矿床中的储量最大的矿床,前人勘探工作表明该矿床外围和深部仍具有较好的找矿前景.在前人研究的基础上,详细勘查沙溪矿床的野外地质情况,重新编录了相关钻孔,确定了沙溪矿床的蚀变类型以及矿化分布情况,据此建立矿床的矿化带和蚀变带分布模式.在以上工作的基础上进行了详细的室内显微镜下观察和流体包裹体测温工作,对沙溪矿床的成矿流体演化进行了重新的分析厘定,确定了成矿流体的演化过程,查明该矿床成矿流体的成矿物质的沉淀机制,在此基础上,初步提出了矿床的成矿模式.

The copper mineral deposit in Shaxi is a typical intraplate porphyry deposit,located in Lujiang county of Anhui province.The metallogenic belt in the middle and lower reaches of the Changjiang river is one of the typical polymetallic metallogenic belts in the eastern of China.The deposit in Shaxi is the most abundant porphyry copper deposit found in the metallogenic belt in the middle and lower reaches of the Changjiang river.The previous exploration shows that the periphery and deep part of the deposit still have good prospecting potential.On the basis of previous studies,the field geological conditions of deposit in Shaxi are explored in detail,the relevant borehole data are re-recorded,the alteration types and mineralization distribution of deposit in Shaxi are determined,and the distribution patterns of mineralization belt and alteration belt of mineral deposit are established accordingly.On the basis of the above work,detailed indoor microscopic observation and fluid inclusion temperature measurement were carried out.The evolution of metallogenic fluid of the deposit in Shaxi was re-analyzed and determined.The evolution process of metallogenic fluid was determined and the precipitation mechanism of metallogenic fluid of the deposit in Shaxi was identified.On this basis,the metallogenic mode of the mineral deposit is preliminarily proposed.