1. Deep high-temperature hydrothermal circulation in a detachment faulting system on the ultra-slow spreading ridge.
- Author
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Tao, Chunhui, Seyfried, W. E., Lowell, R. P., Liu, Yunlong, Liang, Jin, Guo, Zhikui, Ding, Kang, Zhang, Huatian, Liu, Jia, Qiu, Lei, Egorov, Igor, Liao, Shili, Zhao, Minghui, Zhou, Jianping, Deng, Xianming, Li, Huaiming, Wang, Hanchuang, Cai, Wei, Zhang, Guoyin, and Zhou, Hongwei
- Subjects
MID-ocean ridges ,GOLD ores ,HYDROTHERMAL vents ,MOHOROVICIC discontinuity ,COMPUTER simulation - Abstract
Coupled magmatic and tectonic activity plays an important role in high-temperature hydrothermal circulation at mid-ocean ridges. The circulation patterns for such systems have been elucidated by microearthquakes and geochemical data over a broad spectrum of spreading rates, but such data have not been generally available for ultra-slow spreading ridges. Here we report new geophysical and fluid geochemical data for high-temperature active hydrothermal venting at Dragon Horn area (49.7°E) on the Southwest Indian Ridge. Twin detachment faults penetrating to the depth of 13 ± 2 km below the seafloor were identified based on the microearthquakes. The geochemical composition of the hydrothermal fluids suggests a long reaction path involving both mafic and ultramafic lithologies. Combined with numerical simulations, our results demonstrate that these hydrothermal fluids could circulate ~ 6 km deeper than the Moho boundary and to much greater depths than those at Trans-Atlantic Geotraverse and Logachev-1 hydrothermal fields on the Mid-Atlantic Ridge. Magmatic and tectonic activity at mid-oceanic ridges can give detailed insights into high-temperature hydrothermal circulation of fluids. The authors here present geochemical and geophysical datasets that suggest a hydrothermal system penetrating the upper lithospheric mantle at an ultra-slow spreading mid-oceanic ridge. [ABSTRACT FROM AUTHOR]
- Published
- 2020
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