摘要
根据湘中盆地的水文地质特征,建立了热-重力驱动型的流体运移模型;选择有代表性的龙山-锡矿山剖面,在不同的假设条件下进行锡矿山锑矿床成矿时期流体的热场数值模拟;结合包裹体的研究结论,确定了锡矿山锑矿床的成矿模式:锡矿山锑矿床成矿时期流体主要来源于盆地边缘的大气降水,在运移过程中流体不断被加热,同时淋滤地层中的成矿物质成分,搬运到泥盆系灰岩中卸载成矿。模拟表明在锡矿山锑矿床的下部应有一个隐伏的岩体,它提供的热流值约0.2W/m2。模拟结果还表明,在锡矿山地区成矿作用时期地温梯度约86℃/km,成矿部位的温度约180～200℃,古流体的密度为865～887kg/m3,在成矿部位的流速接近0.5m/a。
A hydrothermal convection model according to the geohydrologic condition of the Central Hunan Basin is established. The Longshan Xikuangshan section is selected to numerically simulate the geothermal field of fluids during ore forming periods of the antimony deposits in Xikuangshan on different hypotheses. Combining with the results of fluid inclusions, the ore forming pattern of the antimony deposits in Xikuangshan is established. The main ore forming fluid of the antimony deposits in Xikuangshan originated from meteoric water at the edge of the basin. Being continually heated and leaching out antimony components of the strata during their movement, the fluids carried them to Devonian limestones forming the antimony deposits. The simulation results show that there lies a concealed rock mass under Xikuangshan, and the heat flow of the mass is 0.2 W/m2. The geothermal gradient during the ore forming periods in Xikuangshan is approximately 86 ℃/km, the temperature of the paleofluid at ore forming position is about 180～200 ℃, the density of the paleofluid is 865～887 kg/m3, and the velocity of the paleofluid near the ore body approaches 0.5 m/a.
出处
《地球化学》
CAS
CSCD
北大核心
2003年第6期509-519,共11页
Geochimica
基金
国家重大基础研究发展规划项目(973项目)(G1999043210)
国家自然科学基金(40073007
40272080)
关键词
锡矿山
锑矿床
成矿流体
热场
湖南
ore forming fluid
numerical simulation
geothermal field
antimony deposit
Xikuangshan
Hunan Province
