Tao
Chunhui
Tao
Chunhui
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ArticleDeep high-temperature hydrothermal circulation in a detachment faulting system on the ultra-slow spreading ridge(Nature Research, 2020-03-10) Tao, Chunhui ; Seyfried, William E. ; Lowell, Robert 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 ; Zhou, Hongwei ; Lin, Jian ; Li, WeiCoupled 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.
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ArticleA reduced crustal magnetization zone near the first observed active hydrothermal vent field on the Southwest Indian Ridge(American Geophysical Union, 2010-09-21) Zhu, Jian ; Lin, Jian ; Chen, Yongshun J. ; Tao, Chunhui ; German, Christopher R. ; Yoerger, Dana R. ; Tivey, Maurice A.Inversion of near-bottom magnetic data reveals a well-defined low crustal magnetization zone (LMZ) near a local topographic high (37°47′S, 49°39′E) on the ultraslow-spreading Southwest Indian Ridge (SWIR). The magnetic data were collected by the autonomous underwater vehicle ABE on board R/V DaYangYiHao in February-March 2007. The first active hydrothermal vent field observed on the SWIR is located in Area A within and adjacent to the LMZ at the local topographic high, implying that this LMZ may be the result of hydrothermal alteration of magnetic minerals. The maximum reduction in crustal magnetization is 3 A/M. The spatial extent of the LMZ is estimated to be at least 6.7 × 104 m2, which is larger than that of the LMZs at the TAG vent field on the Mid-Atlantic Ridge (MAR), as well as the Relict Field, Bastille, Dante-Grotto, and New Field vent-sites on the Juan de Fuca Ridge (JdF). The calculated magnetic moment, i.e., the product of the spatial extent and amplitude of crustal magnetization reduction is at least −3 × 107 Am2 for the LMZ on the SWIR, while that for the TAG field on the MAR is −8 × 107 Am2 and that for the four individual vent fields on the JdF range from −5 × 107 to −3 × 107 Am2. Together these results indicate that crustal demagnetization is a common feature of basalt-hosted hydrothermal vent fields at mid-ocean ridges of all spreading rates. Furthermore, the crustal demagnetization of the Area A on the ultraslow-spreading SWIR is comparable in strength to that of the TAG area on the slow-spreading MAR.
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ArticleHydrothermal plume detection dataset from Chinese cruises to the equatorial East Pacific Rise(Elsevier, 2020-11-20) Chen, Sheng ; Tao, Chunhui ; German, Christopher R.In this data article, a dataset from hydrothermal plume investigations on East Pacific Rise collected during Chinese cruises from 2008 to 2011 is reported. The dataset is related to the research article entitled “Abundance of low-temperature axial venting at the equatorial East Pacific Rise” published in the journal Deep-Sea Research I by Chen et al. (2020). In the dataset, continuous strings of time-series sensor data were obtained by Miniature Autonomous Plume Recorders (MAPR) and an Oxidation-Reduction Potential (ORP) sensor, while the underwater position data was derived using Ultra Short Base Line (USBL) navigation. In this contribution, general characteristics of the data are summarized and showed here. All the data are stored in separate Microsoft Excel spreadsheets that are available for researchers and a link is provided to the full data at http://dx.doi.org/10.17632/jckyj5vyjx.1. The data will be of comparative value to those investigating hydrothermal activities along mid-ocean ridges, worldwide.
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ArticleMineralogical and geochemical features of sulfide chimneys from the 49°39′E hydrothermal field on the Southwest Indian Ridge and their geological inferences(Springer, 2011-08-24) Tao, Chunhui ; Li, Huaiming ; Huang, Wei ; Han, XiQiu ; Wu, GuangHai ; Su, Xin ; Zhou, Ning ; Lin, Jian ; He, YongHua ; Zhou, JianPingDuring January–May in 2007, the Chinese research cruise DY115-19 discovered an active hydrothermal field at 49°39′E/37°47′S on the ultraslow spreading Southwest Indian Ridge (SWIR). This was also the first active hydrothermal field found along an ultraslow-spreading ridge. We analyzed mineralogical, textural and geochemical compositions of the sulfide chimneys obtained from the 49°39′E field. Chimney samples show a concentric mineral zone around the fluid channel. The mineral assemblages of the interiors consist mainly of chalcopyrite, with pyrite and sphalerite as minor constitunets. In the intermediate portion, pyrite becomes the dominant mineral, with chalcopyrite and sphalerite as minor constitunets. For the outer wall, the majority of minerals are pyrite and sphalerite, with few chalcopyrite. Towards the outer margin of the chimney wall, the mineral grains become small and irregular in shape gradually, while minerals within interstices are abundant. These features are similar to those chimney edifices found on the East Pacific Rise and Mid-Atlantic Ridge. The average contents of Cu, Fe and Zn in our chimney samples were 2.83 wt%, 45.6 wt% and 3.28 wt%, respectively. The average Au and Ag contents were up to 2.0 ppm and 70.2 ppm respectively, higher than the massive sulfides from most hydrothermal fields along mid-ocean ridge. The rare earth elements geochemistry of the sulfide chimneys show a pattern distinctive from the sulfides recovered from typical hydrothermal fields along sediment-starved mid-ocean ridge, with the enrichment of light rare earth elements but the weak, mostly negative, Eu anomaly. This is attributed to the distinct mineralization environment or fluid compositions in this area.
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ArticleAn intermittent detachment faulting system with a large sulfide deposit revealed by multi-scale magnetic surveys(Nature Research, 2021-09-24) Wu, Tao ; Tivey, Maurice A. ; Tao, Chunhui ; Zhang, Jinhui ; Zhou, Fei ; Liu, YunlongMagmatic and tectonic processes can contribute to discontinuous crustal accretion and play an important role in hydrothermal circulation at ultraslow-spreading ridges, however, it is difficult to accurately describe the processes without an age framework to constrain crustal evolution. Here we report on a multi-scale magnetic survey that provides constraints on the fine-scale evolution of a detachment faulting system that hosts hydrothermal activity at 49.7°E on the Southwest Indian Ridge. Reconstruction of the multi-stage detachment faulting history shows a previous episode of detachment faulting took place 0.76~1.48 My BP, while the present fault has been active for the past ~0.33 My and is just in the prime of life. This fault sustains hydrothermal circulation that has the potential for developing a large sulfide deposit. High resolution multiscale magnetics allows us to constrain the relative balance between periods of detachment faulting and magmatism to better describe accretionary processes on an ultraslow spreading ridge.