A Preliminary Study on Silver Isotopic Composition in Polymetallic Ore Deposits in Eastern China

Abstract

A preliminary survey of silver isotopic composition in four polymetallic ores in eastern China shows a larger variation in δ¹⁰⁹Ag from −0.014‰ to +0.983‰, which is within the total ranges for the entire respective ore deposit types worldwide. The diversity of silver isotopic compositions in ore-deposits reported here and previous studies seemed to preclude simple isotopic links to particular sources, but reflected the silver isotope fractionation in transport- and deposit-related processes instead. The δ¹⁰⁹Ag values in supergene samples from the Qixiashan Pb−Zn−Ag polymetallic deposit are more positive, in consistent with the statistical δ¹⁰⁹Ag distribution from -0.4‰ to +2.2‰ in 36 pieces of supergene ore samples around the World, which reflects the diverse controls on silver isotope fractionation from the first-order thermodynamic effect, reduction-mediated reaction, remobilization of silver with surficial low-temperature weathering processes. The hypogene samples in Dazhuangzi orogenic Au−Ag ore deposit, have δ¹⁰⁹Ag values close to 0, which implies that equilibrium partitioning associated with metal sources at the high-temperature does not result in a resolvable difference in silver isotopic compositions. By contrast, the hypogene samples which are dominated by pyrite without visible silver minerals (i.e., skarn iron ore deposit in Edongnan) have shown the largest variation range of δ¹⁰⁹Ag, followed by that from the porphyry copper ore in Zijinshan. It could be concluded that the surface adsorption and/or lattice substitution are important factors to control Ag isotope fractionation in ore-forming processes, especially for skarn deposits with only pyrite. The perspective of silver isotope shows great potentials to understand the processes that lead to the concentrations of metals to economic levels and to constrain the physicochemical conditions during ore-mineralization in metallic ore-deposits.

Keywords

silver isotopic composition / hypogene ore deposits / supergene ore deposits / metal transport / ore deposits

References

[1] An Y J, Huang F. A Review of Mg Isotope Analytical Methods by MC-ICP-MS. Journal of Earth Science, 2014, 25(5): 822-840.

[2] Argapadmi W, Toth E R, Fehr M A, . Silver Isotopes as a Source and Transport Tracer for Gold: A Reconnaissance Study at the Sheba and New Consort Gold Mines in the Barberton Greenstone Belt, Kaapvaal Craton, South Africa. Economic Geology, 2018, 113(7): 1553-1570.

[3] Arribas A, Mathur R, Megaw P, . The Isotopic Composition of Silver in Ore Minerals. Geochemistry, Geophysics, Geosystems, 2020, 21(8): e2020gc009097

[4] Ayuso, R. A., 2010. Porphyry Copper Deposit Model: Chapter B in Mineral Deposit Models for Resource Assessment. In: John, D. A., ed., US Geological Survey, Reston. https://doi.org/10.3133/sir20105070b

[5] Bigeleisen J, Mayer M G. Calculation of Equilibrium Constants for Isotopic Exchange Reactions. The Journal of Chemical Physics, 1947, 15 5 261-267.

[6] Carlson R W, Hauri E H. Extending the ¹⁰⁷Pd−¹⁰⁷Ag Chronometer to Low Pd/Ag Meteorites with Multicollector Plasma-Ionization Mass Spectrometry. Geochimica et Cosmochimica Acta, 2001, 65(11): 1839-1848.

[7] Chouinard A, Paquette J, Williams-Jones A E. Crystallographic Controls on Trace-Element Incorporation in Auriferous Pyrite from the Pascua Epithermal High-Sulfidation Deposit, Chile Argentina. The Canadian Mineralogist, 2005, 43(3): 951-963.

[8] Chugaev A V, Chernyshev I V. High-Noble Measurement of ¹⁰⁷Ag/¹⁰⁹Ag in Native Silver and Gold by Multicollector Inductively Coupled Plasma Mass Spectrometry (MC-ICP-MS). Geochemistry International, 2012, 50(11): 899-910.

[9] Fujii T, Albarede F. ¹⁰⁹Ag−¹⁰⁷Ag Fractionation in Fluids with Applications to Ore Deposits, Archeometry, and Cosmochemistry. Geochimica et Cosmochimica Acta, 2018, 234: 37-49.

[10] Gaillardet J. Lemarchand D, Marschall H, Foster G. Boron in the Weathering Environment. Boron Isotopes, Advances in Isotope Geochemistry, 2018, Cham: Springer

[11] Graybeal F T, Vikre P G. A Review of Silver-Rich Mineral Deposits and Their Metallogeny. The Challenge of Finding New Mineral Resources: Global Metallogeny, Innovative Exploration, and New Discoveries, 2010, New York: GSW

[12] Gui C J, Jing S. Ore-Forming Properties and Prospect of Pb−Zn Polymetallic Ore Deposit in Qixia Mountain of Nanjing. Journal of Geology, 2011, 35(4): 395-400

[13] Guo Q, Wei H Z, Jiang S Y, . Matrix Effects Originating from Coexisting Minerals and Accurate Determination of Stable Silver Isotopes in Silver Deposits. Analytical Chemistry, 2017, 89(24): 13634-13641.

[14] Heinrich C A, Günther D, Audétat A, . Metal Fractionation between Magmatic Brine and Vapor, Determined by Microanalysis of Fluid Inclusions. Geology, 1999, 27(8): 755-758.

[15] Huang R S. Igneous Series and Epithermal Porphyry Cu−Au−Ag Mineralization System in the Zijinshan Ore Field, Fujian Province. Journal of Geomechanics, 2008, 14: 74-86.

[16] Huston D L, Sie S H, Suter G F, . Sulfide Deposits: Part I. Proton Microprobe Analyses of Pyrite, and Part II. Selenium Levels in Pyrite: Comparison with δ³⁴S Values and Implications for the Source of Sulfur in Volcanogenic Hydrothermal Systems. Economic Geology, 1995, 90: 1167-1196.

[17] Jiang B, Zhang T, Wang D H, . Factors Controlling Ore Formation, Regularity and Some Prospecting Strategies for Silver Deposits in China. Acta Geologica Sinica, 2020, 94: 113-126.

[18] Jiang S H, Bagas L, Liang Q L. New Insights into the Petrogenesis of Volcanic Rocks in the Shanghang Basin in the Fujian Province, China. Journal of Asian Earth Sciences, 2015, 105: 48-67.

[19] Jiang S H, Bagas L, Liang Q L. Pyrite Re-Os Isotope Systematics at the Zijinshan Deposit of SW Fujian, China: Constraints on the Timing and Source of Cu−Au Mineralization. Ore Geology Reviews, 2017, 80: 612-622.

[20] Jiang S H, Liang Q L, Bagas L, . Geodynamic Setting of the Zijinshan Porphyry-Epithermal Cu−Au−Mo−Ag Ore System, SW Fujian Province, China: Constrains from the Geochronology and Geochemistry of the Igneous Rocks. Ore Geology Reviews, 2013, 53: 287-305.

[21] Kesler, S. E., Simon, A. C., 2015. Mineral Resources, Economics and the Environment. In: Simon, A. C., ed., Cambridge University Press, Cambridge. https://doi.org/10.1017/cbo9781139871426

[22] King J, Williams-Jones A E, van Hinsberg V, . High-Sulfidation Epithermal Pyrite-Hosted Au (Ag−Cu) Ore Formation by Condensed Magmatic Vapors on Sangihe Island, Indonesia. Economic Geology, 2014, 109(6): 1705-1733.

[23] Liu X, Fan H R, Hu F F, . Ore-Forming Fluid and Stable Isotope Studies of Dazhuangzi Gold Deposit in Jiaodong Peninsula. Mineral Deposits, 2011, 30(4): 675-689

[24] Lu D W, Liu Q, Zhang T Y, . Stable Silver Isotope Fractionation in the Natural Transformation Process of Silver Nanoparticles. Nature Nanotechnology, 2016, 11(8): 682-686.

[25] Luo Y, Dabek-Zlotorzynska E, Celo V, . Accurate and Precise Determination of Silver Isotope Fractionation in Environmental Samples by Multicollector-ICPMS. Analytical Chemistry, 2010, 82(9): 3922-3928.

[26] Mathur R, Arribas A, Megaw P, . Fractionation of Silver Isotopes in Native Silver Explained by Redox Reactions. Geochimica et Cosmochimica Acta, 2018, 224: 313-326.

[27] Migdisov A A, Williams-Jones A E. A Predictive Model for Metal Transport of Silver Chloride by Aqueous Vapor in Ore-Forming Magmatic-Hydrothermal Systems. Geochimica et Cosmochimica Acta, 2013, 104: 123-135.

[28] Pal’Yanova G, Mikhlin Y, Kokh K, . Experimental Constraints on Gold and Silver Solubility in Iron Sulfides. Journal of Alloys and Compounds, 2015, 649: 67-75.

[29] Pals D W, Spry P G, Chryssoulis S L. Invisible Gold and Tellurium in Arsenic-Rich Pyrite from the Emperor Gold Deposit, Fiji: Implications for Gold Distribution and Deposition. Economic Geology, 2003, 98(3): 479-493

[30] Plotinskaya O Y, Groznova E O, Kovalenker V A, . Mineralogy and Formation Conditions of Ores in the Bereznyakovskoe Ore Field, the Southern Urals, Russia. Geology of Ore Deposits, 2009, 51(5): 371-397.

[31] Powell L J, Murphy T J, Gramlich J W. The Absolute Isotopic Abundance and Atomic Weight of a Reference Sample of Silver. Journal of Research of the National Bureau of Standards, 1982, 87(1): 9

[32] Rosman K J R, Taylor P D P. Isotopic Compositions of the Elements 1997 (Technical Report). Pure and Applied Chemistry, 1998, 70 1 217-235.

[33] Savva N E, Pal’Yanova G A, Byankin M A. The Problem of Genesis of Gold and Silver Sulfides and Selenides in the Kupol Deposit (Chukotka, Russia). Russian Geology and Geophysics, 2012, 53(5): 457-466.

[34] Scher S, Williams-Jones A E, Williams-Jones G. Fumarolic Activity, Acid-Sulfate Alteration, and High Sulfidation Epithermal Precious Metal Mineralization in the Crater of Kawah Ijen Volcano, Java, Indonesia. Economic Geology, 2013, 108(5): 1099-1118.

[35] Schönbächler M, Carlson R W, Horan M F, . High Precision Ag Isotope Measurements in Geologic Materials by Multiple-Collector ICPMS: An Evaluation of Dry versus Wet Plasma. International Journal of Mass Spectrometry, 2007, 261(2/3): 183-191.

[36] Schönbächler M, Carlson R W, Horan M F, . Silver Isotope Variations in Chondrites: Volatile Depletion and the Initial ¹⁰⁷Pd Abundance of the Solar System. Geochimica et Cosmochimica Acta, 2008, 72(21): 5330-5341.

[37] Schönbächler M, Carlson R W, Horan M F, . Heterogeneous Accretion and the Moderately Volatile Element Budget of Earth. Science, 2010, 328(5980): 884-887.

[38] Sun X J, Ni P, Yang Y L, . Formation of the Qixiashan Pb−Zn Deposit in Middle-Lower Yangtze River Valley, Eastern China: Insights from Fluid Inclusions and in Situ LA-ICP-MS Sulfur Isotope Data. Journal of Geochemical Exploration, 2018, 192: 45-59.

[39] Taylor S R, McLennan S M. The Continental Crust: Its Composition and Evolution, 1985, London: Blackwell, 57-72

[40] Theis K J, Schönbächler M, Benedix G K, . Palladium-Silver Chronology of IAB Iron Meteorites. Earth and Planetary Science Letters, 2013, 361: 402-411.

[41] Tolaymat T M, El Badawy A M, Genaidy A, . An Evidence-Based Environmental Perspective of Manufactured Silver Nanoparticle in Syntheses and Applications: A Systematic Review and Critical Appraisal of Peer-Reviewed Scientific Papers. Science of the Total Environment, 2010, 408(5): 999-1006.

[42] Voisey C R, Maas R, Tomkins A G, . Extreme Silver Isotope Variation in Orogenic Gold Systems Implies Multistaged Metal Remobilization during Ore Genesis. Economic Geology, 2019, 114(2): 233-242.

[43] Widler A M, Seward T M. The Adsorption of Gold(I) Hydrosulphide Complexes by Iron Sulphide Surfaces. Geochimica et Cosmochimica Acta, 2002, 66(3): 383-402.

[44] Woodland S J, Rehkämper M, Halliday A N, . Accurate Measurement of Silver Isotopic Compositions in Geological Materials Including Low Pd/Ag Meteorites. Geochimica et Cosmochimica Acta, 2005, 69(8): 2153-2163.

[45] Xie G Q, Mao J W, Li R L, . Geological Characteristics and Mineral Model of Skarn Fe Deposits from Southeastern Hubei Province, China. Mineral Deposits, 2006, 25(S1): 147-150

[46] Xu Z F, Zeng Z H. Discussions on Relationship between Mineralization and Magmatism in Qixiashan Pb−Zn−Ag Ore Deposit of Nanjing. Jiangsu Geology, 2006, 30(3): 177-182

[47] Yang L, Dabek-Zlotorzynska E, Celo V. High Precision Determination of Silver Isotope Ratios in Commercial Products by MC-ICP-MS. Journal of Analytical Atomic Spectrometry, 2009, 24(11): 1564-1569.

[48] Yang L, Sturgeon R E, Mester Z, . Metrological Triangle for Measurements of Isotope Amount Ratios of Silver, Indium, and Antimony Using Multicollector-Inductively Coupled Plasma Mass Spectrometry: The 21st Century Harvard Method. Analytical Chemistry, 2010, 82(21): 8978-8982.

[49] Zhang G S. Characteristics of the Structures and Their Rock and Ore Control Low. Hubei Geology & Mineral Resources, 1998, 12(2): 16-23

[50] Zhang J Z. Geology, Exploration Model and Practice of Zijinshan Ore Concentrated Area. Mineral Deposits, 2013, 32(4): 758-767

[51] Zhang T, Lu D, Zeng L, . Role of Secondary Particle Formation in the Persistence of Silver Nanoparticles in Humic Acid Containing Water under Light Irradiation. Environmental Science & Technology, 2017, 51(24): 14164-14172.

[52] Zhong J, Chen Y J, Qi J P, . Geology, Fluid Inclusion and Stable Isotope Study of the Yueyang Ag−Au−Cu Deposit, Zijinshan Orefield, Fujian Province, China. Ore Geology Reviews, 2017, 86: 254-270.

[53] Zhu D G, Lu G X, Deng J, . Discussion on the Geology and Genesis of Dazhuangzi Gold Deposit in Eastern Shandong Province. Journal of Precious Metallic Geology, 1999, 8(2): 18-23

[54] Zhu Y F, Dong G, Liu X, . Progress of Silver Isotopes Studies in Planetary and Earth Sciences. Earth Science, 2021, 46(12): 4390-4404