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2005年在西南印度洋脊49.6°E发现热液异常,并于2007年取得硫化物样品,这是首个在全球超慢速扩张洋脊发现活动的海底热液区。对该区硫化物开展了矿物学和矿物化学研究。结果表明,西南印度洋脊49.6°E热液区硫化物可划分出富Zn和富Fe两种矿石自然类型,矿石中广泛发育溶蚀孔洞构造、“黄铜矿疾病”结构、网格状固溶体分解结构、同质增生结构等结构构造。根据矿物化学成分变化,矿石矿物可划分出Fe-S系列、Zn-S系列、Cu-Fe-S系列、Cu-S系列及Au、Cu、W自然金属系列等。该区硫化物的沉积过程可划分为2个阶段:Ⅰ.富Zn硫化物沉积阶段,矿物组合以闪锌矿-黄铁矿-黄铜矿为主,成矿流体沉积温度相对较低;Ⅱ.富Fe硫化物阶段,矿物组合以黄铁矿-白铁矿-闪锌矿-等轴古巴矿为主,成矿流体沉积温度相对较高。后期沉积过程(阶段Ⅱ)对早期沉积过程(阶段Ⅰ)的硫化物进行了部分叠加改造。
Hydrocarbon anomalies were discovered at 49.6 ° E on the Indian Ocean Ridge in Southwest China in 2005 and sulfide samples were obtained in 2007, the first seabed hydrothermal region found in the world’s ultra-slow expansion oceanic ridges. Sulfides in the area carried out mineralogy and mineral chemistry. The results show that the 49.6 ° E hydrothermal sulfide in the southwestern Indian Ocean Ridge can be divided into natural types rich in Zn and Fe, and the dissolution pore structure is widely developed in the ores of “chalcopyrite disease” and the grid-like solid solution Decomposition structure, homogeneity structure and other structural structure. According to changes in mineral chemical composition, ore minerals can be divided into Fe-S series, Zn-S series, Cu-Fe-S series, Cu-S series and Au, Cu, W natural metal series. The deposition process of sulphides in this area can be divided into two stages: Ⅰ. In Zn-rich sulphide deposition stage, the mineral assemblage is dominated by sphalerite-pyrite-chalcopyrite and the deposition temperature of ore-forming fluids is relatively low; Ⅱ In the Fe - rich sulphide phase, the mineral assemblage is dominated by pyrite - marcasite - sphalerite - equiaxed Cuban mine, and the deposition temperature of ore - forming fluids is relatively high. Post-depositional processes (Stage II) partially modified the sulphides of the early sedimentation (Stage I).