Mode of silver occurrence in pyrite from the Edmond hydrothermal field, Central Indian Ridge: mineralogical evidence

CHEN Kean; ZHANG Huichao; FANG Haoyuan; TAO Chunhui; LIANG Jin; YANG Weifang; LIAO Shili

doi:10.16562/j.cnki.0256-1492.2022101101

Marine Geology & Quaternary Geology > 2023 > 43(3): 84-92. > DOI: 10.16562/j.cnki.0256-1492.2022101101

CHEN Kean，ZHANG Huichao，FANG Haoyuan，et al. Mode of silver occurrence in pyrite from the Edmond hydrothermal field, Central Indian Ridge: mineralogical evidence[J]. Marine Geology & Quaternary Geology，2023，43(3)：84-92. DOI: 10.16562/j.cnki.0256-1492.2022101101

Citation:

PDF (4075 KB)

Mode of silver occurrence in pyrite from the Edmond hydrothermal field, Central Indian Ridge: mineralogical evidence

1.
College of Oceanography, Hohai University, Nanjing 210098, China
2.
Key Laboratory of Submarine Geoscience, Second Institute of Oceanography, Ministry of Nature Resources, Hangzhou 310012, China
3.
School of Earth Sciences and Engineering, Nanjing 210023, China
4.
School of Oceanography, Shanghai Jiao Tong University, Shanghai 200240, China

More Information

Received Date: October 10, 2022
Revised Date: January 12, 2023
Available Online: July 17, 2023

Graphical Abstract

Abstract

Abstract

With the increase in study on submarine polymetallic sulfides, the mechanisms of occurrence and precipitation of gold and silver have become a hotspot of research. Compared with gold, the precipitation mechanism of silver from the hydrothermal field at mid-ocean ridge is poorly studied. The sulfide samples from Edmond hydrothermal field were studied in optical microscopy and scanning electron microscopy. The mineral assemblage, stages of mineralization and the occurrence of native silver were determined, and precipitation mechanism of native silver were also discussed. Results show that the average silver content in the samples was 47×10⁻⁶, which is significantly higher than that (2.78×10⁻⁶) in sulfide ores from hydrothermal fields of the mid-ocean ridge. Sphalerite was the most abundant sulfide, followed by pyrite, marcasite and chalcopyrite; other minerals including ferrinatrite, barite, anhydrite, and native silver were also observed. In mineral texture and assemblages, the sulfide mineralization process could be divided into three stages. The mineral assemblages in first stage contained pyrite (Py1), barite, and anhydrite; the second stage contained marcasite, and the third stage included pyrite (Py2), chalcopyrite, coarse sphalerite, and isocubanite. Native silver existed mainly in the form of fine particles at the edge or inner inclusions of Py1. The main existing form of silver in the Edmond hydrothermal field was AgCl₂^-. The decrease in Cl^- concentration, the increase in pH value, and the decrease in temperature caused by the mixing of high temperature hydrothermal and seawater were the main factors on the native silver precipitation.
- submarine sulfide deposit,
- occurrence of silver,
- precipitation mechanism,
- Edmond hydrothermal field,
- central Indian Ridge

FullText(HTML)

References (42)

References

[1]	Lin J, Zhang C. The first collaborative China-international cruises to investigate mid-ocean ridge hydrothermal vents [J]. InterRidge News, 2006, 15: 33-34.
[2]	陶春辉, 李怀明, 金肖兵, 等. 西南印度洋脊的海底热液活动和硫化物勘探[J]. 科学通报, 2014, 59(19):2266-2276 doi: 10.1007/s11434-014-0182-0 Tao C H, Li H M, Jin X B, et al. Seafloor hydrothermal activity and polymetallic sulfide exploration on the southwest Indian ridge [J]. Chinese Science Bulletin, 2014, 59(19): 2266-2276. doi: 10.1007/s11434-014-0182-0
[3]	Hannington M D, De Ronde C E J, Petersen S. Sea-floor tectonics and submarine hydrothermal systems[M]//Hedenquist J W, Thompson J F H, Goldfarb R J, et al. One Hundredth Anniversary Volume. Littleton: Society of Economic Geologists, 2005: 111-141.
[4]	Herzig P M, Hannington M D. Polymetallic massive sulfides at the modern seafloor a review [J]. Ore Geology Reviews, 1995, 10(2): 95-115. doi: 10.1016/0169-1368(95)00009-7
[5]	Connelly D P, Copley J T, Murton B J, et al. Hydrothermal vent fields and chemosynthetic biota on the world's deepest seafloor spreading centre [J]. Nature Communications, 2012, 3: 620. doi: 10.1038/ncomms1636
[6]	Hannington M, Jamieson J, Monecke T, et al. The abundance of seafloor massive sulfide deposits [J]. Geology, 2011, 39(12): 1155-1158. doi: 10.1130/G32468.1
[7]	Bach W, Banerjee N R, Dick H J B, et al. Discovery of ancient and active hydrothermal systems along the ultra-slow spreading Southwest Indian Ridge 10°-16°E [J]. Geochemistry, Geophysics, Geosystems, 2002, 3(7): 1-14.
[8]	Dias Á S, Barriga F J A S. Mineralogy and geochemistry of hydrothermal sediments from the serpentinite-hosted Saldanha hydrothermal field (36°34′N; 33°26′W) at MAR [J]. Marine Geology, 2006, 225(1-4): 157-175. doi: 10.1016/j.margeo.2005.07.013
[9]	Ye J, Shi X F, Yang Y M, et al. The occurrence of gold in hydrothermal sulfide at Southwest Indian Ridge 49.6°E [J]. Acta Oceanologica Sinica, 2012, 31(6): 72-82. doi: 10.1007/s13131-012-0254-4
[10]	Fuchs S, Hannington M D, Petersen S. Divining gold in seafloor polymetallic massive sulfide systems [J]. Mineralium Deposita, 2019, 54(6): 789-820. doi: 10.1007/s00126-019-00895-3
[11]	Huston D L, Relvas J M R S, Gemmell J B, et al. The role of granites in volcanic-hosted massive sulphide ore-forming systems: an assessment of magmatic–hydrothermal contributions [J]. Mineralium Deposita, 2011, 46(5): 473-507.
[12]	Knight R D, Roberts S, Webber A P. The influence of spreading rate, basement composition, fluid chemistry and chimney morphology on the Formation of gold-rich SMS deposits at slow and ultraslow mid-ocean ridges [J]. Mineralium Deposita, 2018, 53(1): 143-152. doi: 10.1007/s00126-017-0762-4
[13]	罗洪明, 韩喜球, 王叶剑, 等. 全球现代海底块状硫化物战略性金属富集机理及资源前景初探[J]. 地球科学, 2021, 46(9):3123-3138 LUO Hongming, HAN Xiqiu, WANG Yejian, et al. Preliminary study on the enrichment mechanism of strategic metals and their resource prospects in global modern seafloor massive sulfide deposits [J]. Earth Science, 2021, 46(9): 3123-3138.
[14]	杨铭, 王叶剑, 韩喜球, 等. 超镁铁岩型海底热液成矿系统中Au的矿化: 以卡尔斯伯格脊天休热液区为例[J]. 地质论评, 2021, 67(S1):173-174 YANG Ming, WANG Yejian, HAN Xiqiu, et al. Gold mineralization in the ultramafic-hosted seafloor hydrothermal systems: examples from the Tianxiu Vent Field, Carlsberg Ridge [J]. Geological Review, 2021, 67(S1): 173-174.
[15]	Hannington M D, Peter J M, Scott S D. Gold in sea-floor polymetallic sulfide deposits [J]. Economic Geology, 1986, 81(8): 1867-1883. doi: 10.2113/gsecongeo.81.8.1867
[16]	Herzig P M, Hannington M D, Fouquet Y, et al. Gold-rich polymetallic sulfides from the Lau back arc and implications for the geochemistry of gold in sea-floor hydrothermal systems of the Southwest Pacific [J]. Economic Geology, 1993, 88(8): 2182-2209. doi: 10.2113/gsecongeo.88.8.2182
[17]	张海桃, 杨耀民, 梁娟娟, 等. 全球现代海底块状硫化物矿床资源量估计[J]. 海洋地质与第四纪地质, 2014, 34(5):107-118 ZHANG Haitao, YANG Yaomin, LIANG Juanjuan, et al. A global estimate of resource potential for modern seafloor massive sulfide deposits [J]. Marine Geology & Quaternary Geology, 2014, 34(5): 107-118.
[18]	Wu Z W, Sun X M, Xu H F, et al. Occurrences and distribution of “invisible” precious metals in sulfide deposits from the Edmond hydrothermal field, Central Indian Ridge [J]. Ore Geology Reviews, 2016, 79: 105-132. doi: 10.1016/j.oregeorev.2016.05.006
[19]	Wu Z W, Sun X M, Xu H F, et al. Microstructural characterization and in-situ sulfur isotopic analysis of silver-bearing sphalerite from the Edmond hydrothermal field, Central Indian Ridge [J]. Ore Geology Reviews, 2018, 92: 318-347. doi: 10.1016/j.oregeorev.2017.11.024
[20]	Mendel V, Sauter D, Parson L, et al. Segmentation and morphotectonic variations along a super slow-spreading center: the Southwest Indian Ridge (57° E-70° E) [J]. Marine Geophysical Researches, 1997, 19(6): 505-533. doi: 10.1023/A:1004232506333
[21]	Georgen J E, Lin J, Dick H J B. Evidence from gravity anomalies for interactions of the Marion and Bouvet hotspots with the Southwest Indian Ridge: effects of transform offsets [J]. Earth and Planetary Science Letters, 2001, 187(3-4): 283-300. doi: 10.1016/S0012-821X(01)00293-X
[22]	DeMets C, Gordon R G, Argus D F, et al. Effect of recent revisions to the geomagnetic reversal time scale on estimates of current plate motions [J]. Geophysical Research Letters, 1994, 21(20): 2191-2194. doi: 10.1029/94GL02118
[23]	王叶剑, 韩喜球, 金翔龙, 等. 中印度洋脊Edmond区热液硫化物的形成: 来自铅和硫同位素的约束[J]. 吉林大学学报:地球科学版, 2012, 42(S2):234-242,308 WANG Yejian, HAN Xiqiu, JIN Xianglong, et al. Formation of hydrothermal sulfides precipitates in the Edmond field, Central Indian Ridge: lead and sulfur isotope constraints [J]. Journal of Jilin University:Earth Science Edition, 2012, 42(S2): 234-242,308.
[24]	Briais A. Structural analysis of the segmentation of the Central Indian Ridge between 20°30′S and 25°30′S (Rodriguez Triple Junction) [J]. Marine Geophysical Researches, 1995, 17(5): 431-467. doi: 10.1007/BF01371787
[25]	Gamo T, Chiba H, Yamanaka T, et al. Chemical characteristics of newly discovered black smoker fluids and associated hydrothermal plumes at the Rodriguez Triple Junction, Central Indian Ridge [J]. Earth and Planetary Science Letters, 2001, 193(3-4): 371-379. doi: 10.1016/S0012-821X(01)00511-8
[26]	Humphris S E, Fornari D J. Hydrothermal vents in an unusual geotectonic setting: the Kairei and Edmond vent fields, Central Indian Ridge[C]//AGU Fall Meeting. AGU, 2001: OS41A-0444.
[27]	王叶剑, 韩喜球, 金翔龙, 等. 中印度洋脊Edmond热液区黄铁矿的标型特征及其对海底成矿作用环境的指示[J]. 矿物学报, 2011, 31(2):173-179 WANG Yejian, HAN Xiqiu, JIN Xianglong, et al. Typomorphic characteristics of pyrite and its metallogenic environment of Edmond hydrothermal field, Central Indian Ridge [J]. Acta Mineralogica Sinica, 2011, 31(2): 173-179.
[28]	Gallant R M, Von Damm K L. Geochemical controls on hydrothermal fluids from the Kairei and Edmond Vent Fields, 23°–25°S, Central Indian Ridge [J]. Geochemistry, Geophysics, Geosystems, 2006, 7(6): Q06018. doi: 10.1029/2005gc001067
[29]	Kumagai H, Nakamura K, Toki T, et al. Geological background of the Kairei and Edmond hydrothermal fields along the Central Indian Ridge: implications of their vent fluids’ distinct chemistry [J]. Geofluids, 2008, 8(4): 239-251. doi: 10.1111/j.1468-8123.2008.00223.x
[30]	Van Dover C L, Humphris S E, Fornari D, et al. Biogeography and ecological setting of Indian Ocean hydrothermal vents [J]. Science, 2001, 294(5543): 818-823. doi: 10.1126/science.1064574
[31]	李军, 孙治雷, 黄威, 等. 现代海底热液过程及成矿[J]. 地球科学——中国地质大学学报, 2014, 39(3):312-324 LI Jun, SUN Zhilei, HUANG Wei, et al. Modern seafloor hydrothermal processes and mineralization [J]. Earth Science—Journal of China University of Geosciences, 2014, 39(3): 312-324.
[32]	Cook N J, Ciobanu C L, Pring A, et al. Trace and minor elements in sphalerite: a LA-ICPMS study [J]. Geochimica et Cosmochimica Acta, 2009, 73(16): 4761-4791. doi: 10.1016/j.gca.2009.05.045
[33]	Sugaki A, Shima H, Kitakaze A, et al. Isothermal phase relations in the system Cu-Fe-S under hydrothermal conditions at 350 degrees C and 300 degrees C [J]. Economic Geology, 1975, 70(4): 806-823. doi: 10.2113/gsecongeo.70.4.806
[34]	Lusk J, Bray D M. Phase relations and the electrochemical determination of sulfur fugacity for selected reactions in the Cu–Fe–S and Fe–S systems at 1 bar and temperatures between 185 and 460 °C [J]. Chemical Geology, 2002, 192(3-4): 227-248. doi: 10.1016/S0009-2541(02)00194-8
[35]	Benning L G, Seward T M. Hydrosulphide complexing of Au (I) in hydrothermal solutions from 150-400°C and 500-1500 bar [J]. Geochimica et Cosmochimica Acta, 1996, 60(11): 1849-1871. doi: 10.1016/0016-7037(96)00061-0
[36]	Gibert F, Pascal M L, Pichavant M. Gold solubility and speciation in hydrothermal solutions: experimental study of the stability of hydrosulphide complex of gold (AuHS°) at 350 to 450°C and 500 bars [J]. Geochimica et Cosmochimica Acta, 1998, 62(17): 2931-2947. doi: 10.1016/S0016-7037(98)00209-9
[37]	Stefánsson A, Seward T M. Gold(I) complexing in aqueous sulphide solutions to 500°C at 500 bar [J]. Geochimica et Cosmochimica Acta, 2004, 68(20): 4121-4143. doi: 10.1016/j.gca.2004.04.006
[38]	Moss R, Scott S D. Geochemistry and mineralogy of gold-rich hydrothermal precipitates from the eastern Manus Basin, Papua New Guinea [J]. The Canadian Mineralogist, 2001, 39(4): 957-978. doi: 10.2113/gscanmin.39.4.957
[39]	Pal'yanova G. Physicochemical modeling of the coupled behavior of gold and silver in hydrothermal processes: gold fineness, Au/Ag ratios and their possible implications [J]. Chemical Geology, 2008, 255(3-4): 399-413. doi: 10.1016/j.chemgeo.2008.07.010
[40]	Gammons C H, Williams-Tones A E. The solubility of Au-Ag alloy + AgCl in HCl/NaCl solutions at 300°C: new data on the stability of Au (Ⅰ) chloride complexes in hydrothermal fluids [J]. Geochimica et Cosmochimica Acta, 1995, 59(17): 3453-3468. doi: 10.1016/0016-7037(95)00234-Q
[41]	Shikazono N, Shimizu M. The Ag/Au ratio of native gold and electrum and the geochemical environment of gold vein deposits in Japan [J]. Mineralium Deposita, 1987, 22(4): 309-314.
[42]	Seward T M, Williams-Jones A E, Migdisov A A. The chemistry of metal transport and deposition by ore-forming hydrothermal fluids [J]. Treatise on Geochemistry, 2014, 13: 29-57.