大西洋中脊热液硫化物的矿物学研究

利用１９８９年在大西洋热液活动区采集的块状硫化物样品，采用矿相显微镜、电子显微镜和电子探针等手段，进行了矿物共生组合、矿物形态与成分标型及其演化特征研究。结果表明，大西洋热液成矿作用可以划分为热液期与沉积期两个成矿期，和石英－黄铁矿阶段、黄铁矿阶段、多金属硫化物阶段、胶状黄铁矿阶段和非晶质ＳｉＯ２阶段等５个成矿阶段；不同成矿阶段黄铁矿的共生矿物和矿物特征不同，在晶体形态上具有从单形晶－聚形晶－胶状

MINERALOGICAL STUDY OF HYDROTHERMAL SULFIDE FROM THE MID-ATLANTIC RIDGE

This paper refers to a research result of massive sulfide sampled from the Atlantic Ocean in 1989. Studies of mineral association , composition typomorphic and their evolu-tion features were carried out. The methods of ore microscope , electron microscope and electron microprobe were adopted. The results show that hydrothermal deposits in the Atlantic Ocean can be divided into two minerogenetic periods and into five minerogenetic stages,i.e. ,quartz-pyrite stage, pyrite stage, polymetallic sulfide stage, gel- pyrite stage and amorphous silicon dioxide stage. Paragenetic minerals and mineral featues of the pyrites at different stages were various. In crystal form , there was an evolution trend from simple form to combination form and then to colloid form. Euhedral degree gradu-ally decreased. In chemical composition , there were characteristics that impurities,S/Fe ratio and As +Sb +Se +Te amount gradually increased,Both chalcopyrite and sphalerite had two kinds of producing ways. Sp1 and Cp1 were formed under the condition of high-temperature , while Sp2 and Cp2 were formed under relatively low temperature. The hy-drothermal minerogenetic process in the Atlantic Ocean underwent the process from high temperature to low temperature. The highest temperature was in excess of five hundred degrees centigrade. The lowest temperature was down to seawater temperature.Major minerogenetic stage was at the late hydrothermal activity and deposition stage.Pyrite at depositional stage was characteristic of framboid texture that is of important indicative significance in study on origin of sedimentary deposits.