TY - JOUR TI - Geochemistry, sulfur and lead isotopic composition of hydrothermal sulfide from the Duanqiao hydrothermal field on the Southwest Indian Ridge: implications for ore genesis AU - Yang, Weifang AU - Liao, Shili AU - Alveirinho Dias, Ágata AU - Liang, Jin AU - Li, Wei AU - Ding, Teng AU - Tao, Chunhui T2 - International Geology Review AB - Hydrothermal activities on ultraslow-spreading ridges exhibit diverse characteristics, long histories with multiple participants, and might form large-scale, high-grade sulfide deposits. The Duanqiao hydrothermal field (DHF) is located at the segment with the thickest oceanic crust and a large axial magma chamber on the Southwest Indian Ridge, providing unique perspective of sulfide metallogenesis on ultraslow-spreading ridges. Previous studies revealed that DHF sulfide exhibits distinct features of enrichment of ore-forming elements in comparison with those of hydrothermal fields on sediment-starved mid-ocean ridges. However, the genesis and processes responsible for such differences remain poorly constrained. In this study, mineralogical, geochemical and S and Pb isotopic analyses were performed on relict sulfide mound samples to characterize DHF formation. The samples show clear concentric mineral zonation from the interior to the exterior wall. Assemblages of chalcopyrite, sphalerite, and pyrite are distributed mainly in the interior wall, whereas pyrite and marcasite are distributed mainly in the exterior wall. The low Cu content and Pb isotopic composition of the sulfide indicate that the metals are derived mainly from basement basalts. The δ34S values exhibit positive values distributed over a reasonably narrow range (2.42‰–7.97‰), which suggests approximately 62.1%–88.5% of S with basaltic origin. Compared with most hydrothermal fields along the sediment starved mid-ocean ridges, the DHF sulfide shows particularly high contents of Pb (263–2630 ppm), As (234–726 ppm), Sb (7.32–44.3 ppm), and Ag (35.2 to >100 ppm). The δ34S values exhibit an increasing tendency from the sample exterior to the interior. We propose that these features probably reflect the existence of a subsurface zone refining process. Our results provide new insight into the sulfide formation process and contribute to understanding the metallogenic mechanism of hydrothermal sulfides on ultraslow-spreading ridges. DA - 2022/05/31/ PY - 2022 DO - 10.1080/00206814.2022.2081937 DP - Taylor and Francis+NEJM VL - 0 IS - 0 SP - 1 EP - 17 SN - 0020-6814 ST - Geochemistry, sulfur and lead isotopic composition of hydrothermal sulfide from the Duanqiao hydrothermal field on the Southwest Indian Ridge UR - https://doi.org/10.1080/00206814.2022.2081937 Y2 - 2022/09/21/13:41:13 KW - Hydrothermal sulfide KW - geochemistry KW - southwest Indian ridge KW - sulfur isotope KW - zone refining ER - TY - JOUR TI - Hydrothermal remobilization of subseafloor sulfide mineralization along mid-ocean ridges contributes to the global oceanic zinc isotopic mass balance AU - Liao, Shili AU - Tao, Chunhui AU - Wen, Hanjie AU - Yang, Weifang AU - Liu, Jia AU - Jamieson, John W. AU - Dias, Ágata Alveirinho AU - Zhu, Chuanwei AU - Liang, Jin AU - Li, Wei AU - Ding, Teng AU - Li, Xiaohu AU - Zhang, Huichao T2 - Geochimica et Cosmochimica Acta AB - Hydrothermal activity on mid-ocean ridges is an important mechanism for the delivery of Zn from the mantle to the surface environment. Zinc isotopic fractionation during hydrothermal activity is mainly controlled by the precipitation of Zn-bearing sulfide minerals, in which isotopically light Zn is preferentially retained in solid phases rather than in solution during mineral precipitation. Thus, seafloor hydrothermal activity is expected to supply isotopically heavy Zn to the ocean. Here, we studied sulfide-rich samples from the Duanqiao-1 hydrothermal field, located on the Southwest Indian Ridge. We report that, at the hand-specimen scale, late-stage conduit sulfide material has lower δ66Zn values (−0.05 ± 0.15 ‰; n = 19) than early-stage material (+0.13 ± 0.15 ‰; n = 10). These lower values correlate with enrichments in Pb, As, Cd, and Ag, and elevated δ34S values. We attribute the low δ66Zn values to the remobilization of earlier sub-seafloor Zn-rich mineralization. Based on endmember mass balance calculations, and an assumption of a fractionation factor (αZnS-Sol.) of about 0.9997 between sphalerite and its parent solution, the remobilized Zn was found consist of about 1/3 to 2/3 of the total Zn in the fluid that formed the conduit samples. Our study suggests that late-stage subsurface hydrothermal remobilization may release isotopically-light Zn to the ocean, and that this process may be common along mid-ocean ridges, thus increasing the size of the previously identified isotopically light Zn sink in the ocean. DA - 2022/10/15/ PY - 2022 DO - 10.1016/j.gca.2022.08.022 DP - ScienceDirect VL - 335 SP - 56 EP - 67 J2 - Geochimica et Cosmochimica Acta LA - en SN - 0016-7037 UR - https://www.sciencedirect.com/science/article/pii/S0016703722004410 Y2 - 2022/09/21/13:41:02 KW - Hydrothermal activity KW - Mid ocean ridge KW - Subsurface remobilization KW - Zinc isotopic mass balance ER - TY - JOUR TI - Sulfur isotopic compositions of sulfides along the Southwest Indian Ridge: implications for mineralization in ultramafic rocks AU - Dias, Ágata AU - Ding, Teng AU - Tao, Chunhui AU - Liang, Jin AU - Chen, Jie AU - Wu, Bin AU - Ma, Dongsheng AU - Zhang, Rongqing AU - Wang, Jia AU - Liao, Shili AU - Wang, Yuan AU - Yang, Weifang AU - Liu, Jia AU - Li, Wei AU - Zhang, Guoyin AU - Huang, Hui T2 - Mineralium Deposita DA - 2020/10/31/ PY - 2020 DO - 10.1007/s00126-020-01025-0 DP - DOI.org (Crossref) J2 - Miner Deposita LA - en SN - 0026-4598, 1432-1866 ST - Sulfur isotopic compositions of sulfides along the Southwest Indian Ridge UR - http://link.springer.com/10.1007/s00126-020-01025-0 Y2 - 2021/03/30/07:28:44 ER - TY - JOUR TI - Surface sediment composition and distribution of hydrothermal derived elements at the Duanqiao-1 hydrothermal field, Southwest Indian Ridge AU - Dias, Ágata AU - Liao, Shili AU - Tao, Chunhui AU - Su, Xin AU - Yang, Zhen AU - Ni, Jianyu AU - Liang, Jin AU - Yang, Weifang AU - Liu, Jia AU - Li, Wei AU - Dong, Chuanwan T2 - Marine Geology DA - 2019/10// PY - 2019 DO - 10.1016/j.margeo.2019.105975 VL - 416 SP - 105975 J2 - Marine Geology LA - en SN - 00253227 UR - https://linkinghub.elsevier.com/retrieve/pii/S0025322719300969 Y2 - 2021/03/30/07:30:43 ER -