慢速—超慢速扩张西南印度洋中脊研究进展

西南印度洋中脊具有慢速—超慢速扩张速率和斜向扩张的特征，是全球洋中脊系统研究的热点之一，也是研究海底构造环境、热液活动、地幔深部过程及其动力学机制的重要区域。在前人工作的基础上较为详细地介绍了西南印度洋中脊的研究历史、地形划分、扩张速率及其构造特征，归纳了西南印度洋中脊热液活动及岩石地球化学特征，探讨了超慢速扩张洋脊和超镁铁质岩系热液系统的特殊性，并认为超慢速扩张洋脊广泛暴露的地幔岩及其蛇纹石化作用、超镁铁质岩系热液系统以及热液硫化物成矿作用是西南印度洋中脊今后研究的重要内容。

Advances in Slow-Ultraslow-Spreading Southwest Indian Ridge

Southwest Indian Ridge (SWIR) is characterized by slow spreading to ultraslow spreading rate and oblique spreading, which reveals an ultraslow spreading class of ocean ridge. Recently, SWIR has becoming one of hotspots researching on the global mid ocean ridge systems and also the important region for the study of seafloor tectonic setting, hydrothermal activity, deep process of mantle and its dynamic mechanism. This review summarizes study history, morphologic and structural characteristics, hydrothermal activity and geochemical characteristics of basalt and peridotite in on SWIR. The particularity of both ultraslow spreading ridge and ultramafic hosted hydrothermal system are discussed. The ultraslow and oblique spreading can contribute to generating peridotite and serpentite on ultraslow spreading ridges as well as ultramafic hosted hydrothermal system related to the exothermic serpentinization reactions, which is different from “traditional” basalt hosted hydrothermal system. The more hydrothermal activity and the slower spreading rate may lead to the deposition of larger ore bodies due to their localization on long lived fault structures on SWIR.Therfore, Mantle mantle rocks exposed widely and its serpentinization, ultramafic hosted hydrothermal system and mineralization of hydrothermal sulfide are proposed as the important future avenue of research in on SWIR.