赤道东太平洋海隆水体悬浮颗粒硫化物及其对海底热液活动的指示

Study of Suspended Particulate Sulfides in the Eastern Pacific Rise Area and Their Connection with Sefloor Hydrothermal Activities

基于2011年大洋一号第22次环球考察在东太平洋热液活动区采集的5个站位的77个悬浮体样品,利用扫描电镜与能谱分析相结合的方法,对悬浮颗粒硫化物颗粒的矿物形貌和物相、矿物组合特征以及空间分布进行了系统的研究,探讨了悬浮颗粒矿物组成对海底热液活动的指示作用。研究区出现了闪锌矿、纤锌矿、黄铁矿、白铁矿、磁黄铁矿、黄铜矿、方黄铜矿、铜蓝以及单质硫等多种硫化物颗粒,主要的硫化物矿物包括黄铁矿—闪锌矿—黄铜矿—磁黄铁矿,据此推断该区海底热液属于典型的高温热液流体,其温度在350℃以上。研究区不同站位间悬浮体丰度和保存程度差异明显,这与距离热液活动点远近有着较好的关系。

Based on the 77 samples of suspended matter at 5 stations in the Eastern Pacific Rise hydro- thermal active areas during DY-22 Cruise in 2011, using SEM and EDS methods, we studied morphology, elemental composition and spatial distribution of the suspended particulate sulfide minerals, explored the role of suspended particulate sulfide mineral composition in indicating seafloor hydrothermal activities. Sphalerite, wurtzite, pyrite, marcasite, pyrrhotite, chalcopyrite, covellite, cubanite, and elemental sulfur are identified at the stations. There is a typical sulfide minerals group with pyrite＋ sphalerite＋ chalcopy- rite＋ pyrrhotite in that area, which infer high temperature hydrothermal activity with 〉350℃ at the are- a. The large amount of sulfides such as pyrite, sphalerite and chalcopyrite are found in the 3 southern sta- tions indicating a high-temperature hydrothermal plume in the southern study area.