江西十字头钼矿床流体包裹体特征研究

The Fluid Inclusion Characteristics of Shizitou Mo Deposit in Jiangxi

十字头钼矿床地处扬子地块准地台与华夏地块碰接带南侧,位于近东西向的东乡—广丰深断裂与南北向大断裂交接复合部.对十字头钼矿石英辉钼矿脉中石英流体包裹体进行了矿相学及显微测温研究,结果表明:该区流体包裹体类型较为单一,绝大部分为气液两相包裹体,个体较小(3.5~15μm).均一温度集中分布在340~360℃,盐度集中分布在8%~10%NaCl eqv,成矿流体密度为0.533~0.916 g·cm^(-3),平均值为0.74 g·cm^(-3),具有中高温度、中低盐度与低密度的特征.压力为2.2~26.1 MPa,平均值为14 MPa,其相应的形成深度为近地表至一千米.综合矿床地质特征及流体包裹体研究认为十字头钼矿床为浅成-超浅成斑岩型钼矿床.

The Shizitou Mo Deposit is located in the south of Yangtze massif paraplatform and Huaxia plot collision zone, near the west-east Dongxiang - Gnangfeng deep fracture combination with a big north-south fault. The research on mineralography and the temperature measurements for the fluid inclusion in quartz from the containing molybdenite quartz vein of the Shizitou Mo Deposit indicates that fluid inclusion in this area is predominated by two-phase （liquid-rich） inclusions. The fluid inclusions are usually about 3 - 15 μm in size. The homogenization temperature, salinity and density of fluid inclusion in quartz show that the ore forming fluids have the features of middle-high temperature （340℃ - 360℃ ）, middle-low salinity（8 - 10%NaC1 eqv） and low density（0. 533-0. 916 g · cm-3 ）. The pressure ranges from 2.2 to 26. 1MPa,which is equal to a depth of 0.08 - 1 km. Synthesizing the geological characteristics and the fluid inclusion studies, the Shizitou Mo Deposit can be considered as a hypabyssal-super hypabyssal porphyry type molybdenum deposit.