Abstract
The oxidized nature of the sub-arc mantle and hence arc magmas is generally interpreted as a result of the migration of subduction-related oxidizing fluids or melts from the descending slab into the mantle wedge. This is of particular importance seeing that the oxidization state of sub-arc magmas seems to play a key role in the formations of arc-related ore deposits. However, direct constraints on the redox state of subducted oceanic crust are sparse. Here, we provide a detailed petrological investigation on sulfide- and oxide-bearing eclogites, blueschists, micaschists, eclogite-facies and retrograde veins from the Akeyazi high-pressure (HP) terrane (NW China) in order to gain insight into the redox processes recorded in a subducting oceanic slab. Sulfides in these rocks are mainly pyrite and minor pyrrhotite, chalcopyrite, bornite, molybdenite, sphalerite and chalcocite, including exsolution textures of bornite–chalcopyrite intergrowth. Magnetite, ilmenite and pyrite occur as inclusions in garnet, whereas sulfides are dominant in the matrix. Large pyrite grains in the matrix contain inclusions of garnet, omphacite and other HP index minerals. However, magnetite replacing pyrite textures are commonly observed in the retrograded samples. The eclogite-facies and retrograde veins display two fluid events, which are characterized by an early sulfide-bearing and a later magnetite-bearing mineral assemblage, respectively. Textural and petrological evidences show that the sulfides were mainly formed during HP metamorphism. Mineral assemblage transitions reveal that the relative oxygen fugacity of subducted oceanic crust decreases slightly with increasing depths. However, according to oxygen mass balance calculations, based on the oxygen molar quantities (nO2), the redox conditions remain constant during HP metamorphism. At shallow levels (<60 km) in the subduction channel, interaction with oxidized fluid seems to have caused an increase of the oxygen fugacity and the oxidation state of exhuming HP rocks. This study suggests that oxygen components are not released in significant amounts during HP metamorphism of subducted oceanic crust and, thus, cannot be responsible for oxidizing the mantle wedge and increasing the oxidation state of sub-arc mantle melts.
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References
Alt JC (1995) Sulfur isotopic profile through the oceanic crust: sulfur mobility and seawater-crustal sulfur exchange during hydrothermal alteration. Geology 23:585–588
Alt JC, Shanks WC (1998) Sulfur in serpentinized oceanic peridotites: serpentinization processes and microbial sulfate reduction. J Geophys Res 103:9917–9929
Alt JC, Honnorez J, Laverne C, Emmermann R (1986) Hydrothermal alteration of a 1 km section through the upper oceanic crust, Deep Sea Drilling Project Hole 504B: mineralogy, chemistry and evolution of seawater–basalt interactions. J Geophys Res 91:309–335
Alt JC, Anderson TF, Bonnell L (1989) The geochemistry of sulfur in a 1.3 km section of hydrothermally altered oceanic-crust, DSDP-Hole-504B. Geochim Cosmochim Acta 53:1011–1023
Alt JC, Garrido CJ, Shanks WC, Turchyn A, Padron-Navarta JA, Sanchez-Vizcaino VL, Pugnaire MTG, Marchesi C (2012) Recycling of water, carbon, and sulfur during subduction of serpentinites: a stable isotope study of Cerro del Almirez, Spain. Earth Planet Sci Lett 327:50–60
Alt JC, Schwarzenbach EM, Früh-Green GL, Shanks Iii WC, Bernasconi SM, Garrido CJ, Crispini L, Gaggero L, Padrón-Navarta JA, Marchesi C (2013) The role of serpentinites in cycling of carbon and sulfur: seafloor serpentinization and subduction metamorphism. Lithos 178:40–54
Ballhaus C (1993) Redox states of lithospheric and asthenospheric upper mantle. Contrib Mineral Petrol 114:331–348
Ballhaus C, Berry RF, Green DH (1990) Oxygen fugacity controls in the Earth’s upper mantle. Nature 348:437–440
Ballhaus C, Berry RF, Green DH (1991) High pressure experimental calibration of the olivine-orthopyroxene-spinel oxygen geobarometer: implications for the oxidation state of the upper mantle. Contrib Mineral Petrol 107:27–40
Bancroft GM, Burns RG (1969) Mossbauer and absorption spectral study of alkali amphiboles. Mineral Soc Amer Spec Pap 2:137–148
Barin I (1989) Thermochemical data for pure substances. Wiley, Weinheim
Barton PB (1974) Sulfide petrology. In: Ribbe PH (ed) Sulfide mineralogy. Mineralogical Society of America, Rev Mineral 1:B1–B11
Beard JS, Hopkinson L (2000) A fossil, serpentinization-related hydrothermal vent, Ocean Drilling Program Leg 173, Site 1068 (Iberia Abyssal Plain): some aspects of mineral and fluid chemistry. J Geophys Res 105:16527–16539
Beinlich A, Klemd R, John T, Gao J (2010) Trace-element mobilization during Ca-metasomatism along a major fluid conduit: eclogitization of blueschist as a consequence of fluid-rock interaction. Geochim Cosmochim Acta 74:1892–1922
Berndt ME, Allen DE, Seyfried WE (1996) Reduction of CO2 during serpentinization of olivine at 300 °C and 500 bar. Geology 24:351–354
Breeding CM, Ague JJ, Brocker M (2004) Fluid-metasedimentary rock interactions in subduction-zone mélange: implications for the chemical composition of arc magmas. Geology 32:1041–1044
Brown JL, Christy AG, Ellis DJ, Arculus RJ (2014) Prograde sulfide metamorphism in blueschist and eclogite, New Caledonia. J Petrol 55:643–670
Connolly JAD (2005) Computation of phase equilibria by linear programming: a tool for geodynamic modeling and its application to subduction zone decarbonation. Earth Planet Sci Lett 236:524–541
Dauphas N, Craddock PR, Asimow PD, Bennett VC, Nutman AP, Ohnenstetter D (2009) Iron isotopes may reveal the redox conditions of mantle melting from Archean to Present. Earth Planet Sci Lett 288:255–267
Debret B, Andreani M, Munoz M, Bolfan-Casanova N, Carlut J, Nicollet C, Schwartz S, Trcera N (2014) Evolution of Fe redox state in serpentine during subduction. Earth Planet Sci Lett 400:206–218
Debret B, Bolfan-Casanova N, Padron-Navarta JA, Martin-Hernandez F, Andreani M, Garrido CJ, Sanchez-Vizcaino VL, Gomez-Pugnaire MT, Munoz M, Trcera N (2015) Redox state of iron during high-pressure serpentinite dehydration. Contrib Mineral Petrol 169:36
Du JX, Zhang LF, Shen XJ, Bader T (2014) A new P-T-t path of eclogites from Chinese southwestern Tianshan: constraints from P-T pseudosections and Sm-Nd isochron dating. Lithos 200:258–272
Einaudi MT, Hedenquist JW, Inan EE (2003) Sulfidation state of hydrothermal fluids: the porphyryepithermal transition and beyond. In: Simmons SF, Graham IJ (eds) Volcanic, geothermal and ore-forming fluids: rulers and witnesses of processes within the earth. Soc Econ Geol Geochem Soc Spec Publ 10:285–313
Ernst WG, Wai CM (1970) Mössbauer, infrared, X-ray and optical study of cation ordering and dehydrogenation in natural and heat-treated sodic amphiboles. Am Mineral 55:1226–1258
Evans KA (2006) Redox decoupling and redox budgets: conceptual tools for the study of earth systems. Geology 34:489–492
Evans KA, Tomkins AG (2011) The relationship between subduction zone redox budget and arc magma fertility. Earth Planet Sci Lett 308:401–409
Evans KA, Elburg MA, Kamenetsky VS (2012) Oxidation state of subarc mantle. Geology 40:783–786
Evans KA, Tomkins AG, Cliff J, Fiorentini ML (2014) Insights into subduction zone sulfur recycling from isotopic analysis of eclogite-hosted sulfides. Chem Geol 365:1–19
Foley SF (2011) A reappraisal of redox melting in the Earth’s mantle as a function of tectonic setting and time. J Petrol 52:1363–1391
Frost BR (1985) On the stability of sulfides, oxides and native metals in serpentinites. J Petrol 26:31–63
Frost BR (1991a) Introduction to oxygen fugacity and its petrologic importance. Rev Mineral Geochem 25:1–9
Frost BR (1991b) Stability of oxide minerals in metamorphic rocks. Rev Mineral Geochem 25:469–488
Frost BR, Ballhaus C (1998) Comment on “Constraints on the origin of the oxidation state of mantle overlying subduction zones: an example from Simcoe, Washington, USA”. Geochim Cosmochim Acta 62:329–331
Frost DJ, McCammon CA (2008) The redox state of Earth’s mantle. Annu Rev Earth Planet Sci 36:389–420
Gao J, Klemd R (2001) Primary fluids entrapped at blueschist to eclogite transition: evidence from the Tianshan meta-subduction complex in northwestern China. Contrib Mineral Petrol 142:1–14
Gao J, Klemd R (2003) Formation of HP-LT rocks and their tectonic implications in the western Tianshan Orogen, NW China: geochemical and age constraints. Lithos 66:1–22
Gao J, Li MS, Xiao XC, Tang YQ, He GQ (1998) Paleozoic tectonic evolution of the Tianshan Orogen, northwestern China. Tectonophysics 287:213–231
Gao J, Klemd R, Zhang L, Wang Z, Xiao X (1999) P-T path of high-pressure/low-temperature rocks and tectonic implications in the western Tianshan Mountains, NW China. J Metamorph Geol 17:621–636
Gao J, John T, Klemd R, Xiong XM (2007) Mobilization of Ti-Nb-Ta during subduction: evidence from rutile-bearing dehydration segregations and veins hosted in eclogite, Tianshan, NW China. Geochim Cosmochim Acta 71:4974–4996
Gao J, Long LL, Klemd R, Qian Q, Liu DY, Xiong XM, Su W, Liu W, Wang YT, Yang FQ (2009) Tectonic evolution of the South Tianshan orogen and adjacent regions, NW China: geochemical and age constraints of granitoid rocks. Int J Earth Sci 98:1221–1238
Gao J, Klemd R, Qian Q, Zhang X, Li JL, Jiang T (2011) The collision between the Yili and Tarim blocks of the Southwestern Altaids: geochemical and age constraints of a leucogranite dike crosscutting the HP-LT metamorphic belt in the Chinese Tianshan Orogen. Tectonophysics 499:118–131
Greaves C, Burns RG, Bancroft GM (1971) Resolution of actinolite Mössbauer spectra into three ferrous doublets. Nat Phys Sci 229:60–61
Griffin WL, Begg GC, O’Reilly SY (2013) Continental-root control on the genesis of magmatic ore deposits. Nat Geosci 6:905–910
Groppo C, Castelli D (2010) Prograde P-T evolution of a lawsonite eclogite from the Monviso meta-ophiolite (Western Alps): dehydration and redox reactions during subduction of oceanic FeTi-oxide gabbro. J Petrol 51:2489–2514
Han BF, He GQ, Wang XC, Guo ZJ (2011) Late Carboniferous collision between the Tarim and Kazakhstan-Yili terranes in the western segment of the South Tian Shan Orogen, Central Asia, and implications for the Northern Xinjiang, western China. Earth Sci Rev 109:74–93
Hawthorne FC, Oberti R (2006) On the classification of amphiboles. Can Mineral 44:1–21
Helgeson HC, Kirkham DH, Flowers GC (1981) Theoretical prediction of the thermodynamic behavior of aqueous-electrolytes at high-pressures and temperatures. 4. Calculation of activity coefficients, osmotic coefficients, and apparent molal and standard and relative partial molal properties to 600 °C and 5 kb. Am J Sci 281:1249–1516
Holland TJB, Powell R (2011) An improved and extended internally consistent thermodynamic dataset for phases of petrological interest, involving a new equation of state for solids. J Metamorph Geol 29:333–383
Jahn BM, Wu FY, Chen B (2000) Granitoids of the Central Asian Orogenic Belt and continental growth in the Phanerozoic. Trans R Soc Edinb Earth Sci 91:181–193
Jego S, Dasgupta R (2014) The fate of sulfur during fluid-present melting of subducting basaltic crust at variable oxygen fugacity. J Petrol 55:1019–1050
Jiang T, Gao J, Klemd R, Qian Q, Zhang X, Xiong X, Wang X, Tan Z, Chen B (2014) Paleozoic ophiolitic mélanges from the South Tianshan Orogen, NW China: geological, geochemical and geochronological implications for the geodynamic setting. Tectonophysics 612–613:106–127
John T, Klemd R, Gao J, Garbe-Schönberg CD (2008) Trace-element mobilization in slabs due to non steady-state fluid-rock interaction: constraints from an eclogite-facies transport vein in blueschist (Tianshan, China). Lithos 103:1–24
John T, Scambelluri M, Frische M, Barnes JD, Bach W (2011) Dehydration of subducting serpentinite: implications for halogen mobility in subduction zones and the deep halogen cycle. Earth Planet Sci Lett 308:65–76
John T, Gussone N, Podladchikov YY, Bebout GE, Dohmen R, Halama R, Klemd R, Magna T, Seitz HM (2012) Volcanic arcs fed by rapid pulsed fluid flow through subducting slabs. Nat Geosci 5:489–492
Johnson JW, Oelkers EH, Helgeson HC (1992) SUPCRT92: a software package for calculating the standard molal thermodynamic properties of minerals, gases, aqueous species, and reactions from 1 to 5000 bar and 0 to 1000°C. Comput Geosci 18:899–947
Kawakami T, Ellis DJ, Christy AG (2006) Sulfide evolution in high-temperature to ultrahigh-temperature metamorphic rocks from Lutzow-Holm Complex, East Antarctica. Lithos 92:431–446
Kelley KA, Cottrell E (2009) Water and the oxidation state of subduction zone magmas. Science 325:605–607
Klemd R, Schröter FC, Will TM, Gao J (2002) P-T evolution of glaucophane-omphacite bearing HP-LT rocks in the western Tianshan Orogen, NW China: new evidence for ‘Alpine-type’ tectonics. J Metamorph Geol 20:239–254
Klemd R, John T, Scherer EE, Rondenay S, Gao J (2011) Changes in dip of subducted slabs at depth: petrological and geochronological evidence from HP-UHP rocks (Tianshan, NW-China). Earth Planet Sci Lett 310:9–20
Klemd R, Gao J, Li JL, Meyer M (2015) Metamorphic evolution of (ultra)-high-pressure subduction-related transient crust in the South Tianshan Orogen (Central Asian Orogenic Belt): geodynamic implications. Gondwana Res 28:1–25
Korzhinskii DS (1959) Physicochemical basis of the analysis of the paragenesis of minerals. Consultants Bureau, New York
Lécuyer C, Ricard Y (1999) Long-term fluxes and budget of ferric iron: implication for the redox states of the Earth’s mantle and atmosphere. Earth Planet Sci Lett 165:197–211
Lee CTA, Leeman WP, Canil D, Li ZXA (2005) Similar V/Sc systematics in MORB and arc basalts: implications for the oxygen fugacities of their mantle source regions. J Petrol 46:2313–2336
Lee CTA, Luffi P, Le Roux V, Dasgupta R, Albarede F, Leeman WP (2010) The redox state of arc mantle using Zn/Fe systematics. Nature 468:681–685
Li JL, Klemd R, Gao J, Meyer M (2012) Coexisting carbonate-bearing eclogite and blueschist in SW Tianshan, China: petrology and phase equilibria. J Asian Earth Sci 60:174–187
Li JL, Gao J, John T, Klemd R, Su W (2013) Fluid-mediated metal transport in subduction zones and its link to arc-related giant ore deposits: constraints from a sulfide-bearing HP vein in lawsonite eclogite (Tianshan, China). Geochim Cosmochim Acta 120:326–362
Li JL, Klemd R, Gao J, Meyer M (2014) Compositional zoning in dolomite from lawsonite-bearing eclogite (SW Tianshan, China): evidence for prograde metamorphism during subduction of oceanic crust. Am Mineral 99:206–217
Li JL, Klemd R, Gao J, Jiang T, Song YH (2015) A common high-pressure metamorphic evolution of interlayered eclogites and metasediments from the ‘ultrahigh-pressure unit’ of the Tianshan metamorphic belt in China. Lithos 226:169–182
Li JL, Klemd R, Gao J, John T (2016) Polycyclic metamorphic evolution of eclogite: evidence for multistage burial-exhumation cycling in the subduction channel. J Petrol 57:119–146
Liu X, Su W, Gao J, Li JL, Jiang T, Zhang X, Ge X (2014) Paleozoic subduction erosion involving accretionary wedge sediments in the South Tianshan Orogen: evidence from geochronological and geochemical studies on eclogites and their host metasediments. Lithos 210–211:89–110
Liu Y, Santosh M, Yuan T, Li H, Li T (2016) Reduction of buried oxidized oceanic crust during subduction. Gondwana Res 32:11–23
Lü Z, Zhang LF, Du JX, Bucher K (2008) Coesite inclusions in garnet from eclogitic rocks in western Tianshan, northwest China: convincing proof of UHP metamorphism. Am Mineral 93:1845–1850
Lü Z, Zhang LF, Du JX, Bucher K (2009) Petrology of coesite-bearing eclogite from Habutengsu Valley, western Tianshan, NW China and its tectonometamorphic implication. J Metamorph Geol 27:773–787
Malaspina N, Poli S, Fumagalli P (2009) The oxidation state of metasomatized mantle wedge: insights from C–O–H-bearing garnet peridotite. J Petrol 50:1533–1552
McCulloch MT, Gamble JA (1991) Geochemical and geodynamical constraints on subduction zone magmatism. Earth Planet Sci Lett 102:358–374
Morimoto N, Fabries J, Ferguson AK, Ginzburg IV, Ross M, Seifert FA, Zussman J, Aoki K, Gottardi G (1988) Nomenclature of pyroxenes. Am Mineral 73:1123–1133
Mungall JE (2002) Roasting the mantle: slab melting and the genesis of major Au and Au-rich Cu deposits. Geology 30:915–918
Parkinson IJ, Arculus RJ (1999) The redox state of subduction zones: insights from arc-peridotites. Chem Geol 160:409–423
Pokrovski GS, Borisova AY, Harrichoury JC (2008) The effect of sulfur on vapor-liquid fractionation of metals in hydrothermal systems. Earth Planet Sci Lett 266:345–362
Proyer A, Dachs E, McCammon C (2004) Pitfalls in geothermobarometry of eclogites: Fe3+ and changes in the mineral chemistry of omphacite at ultrahigh pressures. Contrib Mineral Petrol 147:305–318
Richards JP (2015) The oxidation state, and sulfur and Cu contents of arc magmas: implications for metallogeny. Lithos 233:27–45
Rohrbach A, Ballhaus C, Golla-Schindler U, Ulmer P, Kamenetsky VS, Kuzmin DV (2007) Metal saturation in the upper mantle. Nature 449:456–458
Rohrbach A, Ballhaus C, Ulmer P, Golla-Schindler U, Schoenbohm D (2011) Experimental evidence for a reduced metal-saturated upper mantle. J Petrol 52:717–731
Schwarzenbach EM, Gazel E, Caddick MJ (2014) Hydrothermal processes in partially serpentinized peridotites from Costa Rica: evidence from native copper and complex sulfide assemblages. Contrib Mineral Petrol 168:1079
Shen T, Hermann J, Zhang L, Lü Z, Padrón-Navarta JA, Xia B, Bader T (2015) UHP metamorphism documented in Ti-chondrodite- and Ti-clinohumite-bearing serpentinized ultramafic rocks from Chinese Southwestern Tianshan. J Petrol 56:1425–1458
Sillitoe RH (2010) Porphyry copper systems. Econ Geol 105:3–41
Simon AC, Ripley EM (2011) The role of magmatic sulfur in the formation of ore deposits. In: Behrens H, Webster JD (eds), Sulfur in magmas and melts: Its importance for natural and technical processes, Rev Mineral Geochem 73:513–578
Simon AC, Pettke T, Candela PA, Piccoli PM, Heinrich CA (2006) Copper partitioning in a melt-vapor-brine-magnetite-pyrrhotite assemblage. Geochim Cosmochim Acta 70:5583–5600
Stagno V, Ojwang DO, McCammon CA, Frost DJ (2013) The oxidation state of the mantle and the extraction of carbon from Earth’s interior. Nature 493:84–88
Su W, Gao J, Klemd R, Li JL, Zhang X, Li XH, Chen NS, Zhang L (2010) U-Pb zircon geochronology of Tianshan eclogites in NW China: implication for the collision between the Yili and Tarim blocks of the southwestern Altaids. Eur J Mineral 22:473–478
Sun W, Huang RF, Li H, Hu YB, Zhang CC, Sun SJ, Zhang LP, Ding X, Li CY, Zartman RE, Ling MX (2015) Porphyry deposits and oxidized magmas. Ore Geol Rev 65:97–131
Tian ZL, Wei CJ (2014) Coexistence of garnet blueschist and eclogite in the South Tianshan, NW China: dependence of P-T evolution and bulk-rock composition. J Metamorph Geol 32:743–764
Tumiati S, Godard G, Martin S, Malaspina N, Poli S (2015) Ultra-oxidized rocks in subduction mélanges? Decoupling between oxygen fugacity and oxygen availability in a Mn-rich metasomatic environment. Lithos 226:116–130
van der Straaten F, Schenk V, John T, Gao J (2008) Blueschist-facies rehydration of eclogites (Tian Shan, NW-China): implications for fluid-rock interaction in the subduction channel. Chem Geol 255:195–219
Wallace P, Carmichael ISE (1992) Sulfur in basaltic magmas. Geochim Cosmochim Acta 56:1863–1874
Wei CJ, Powell R, Zhang LF (2003) Eclogites from the south Tianshan, NW China: petrological characteristic and calculated mineral equilibria in the Na2O–CaO–FeO–MgO–Al2O3–SiO2–H2O system. J Metamorph Geol 21:163–179
Whitney DL, Evans BW (2010) Abbreviations for names of rock-forming minerals. Am Mineral 95:185–187
Wilkinson JJ (2013) Triggers for the formation of porphyry ore deposits in magmatic arcs. Nat Geosci 6:917–925
Wohlgemuth-Ueberwasser CC, Fonseca ROC, Ballhaus C, Berndt J (2013) Sulfide oxidation as a process for the formation of copper-rich magmatic sulfides. Miner Deposita 48:115–127
Wood BJ, Bryndzia LT, Johnson KE (1990) Mantle oxidation state and its relationship to tectonic environment and fluid speciation. Science 248:337–345
Xiao WJ, Windley BF, Yuan C, Sun M, Han CM, Lin SF, Chen HL, Yan QR, Liu DY, Qin KZ, Li JL, Sun S (2009) Paleozoic multiple subduction-accretion processes of the southern Altaids. Am J Sci 309:221–270
Yang X, Zhang L, Tian Z, Bader T (2013) Petrology and U-Pb zircon dating of coesite-bearing metapelite from the Kebuerte Valley, western Tianshan, China. J Asian Earth Sci 70–71:295–307
Acknowledgments
This work was funded by the National Natural Science Foundation of China (41390445, 41502053, 41025008), China Postdoctoral Science Foundation (2014M560114, 2015T80135) and the Foundation of Key Laboratory of Mineral Resources, Chinese Academy of Sciences. We are grateful to Z. Tan for help with the fieldwork, Q. Mao and Y. G. Ma for help with the electron microprobe analyses. We thank Esther Schwarzenbach and James Connolly for discussion on the calculation of the fO2–fS2 diagrams. Constructive reviews from Stefano Poli and Wolf-Achim Kahl significantly improved the manuscript. Furthermore, thanks are also due to Chris Ballhaus for his editorial handling and thoughtful suggestions.
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Li, JL., Gao, J., Klemd, R. et al. Redox processes in subducting oceanic crust recorded by sulfide-bearing high-pressure rocks and veins (SW Tianshan, China). Contrib Mineral Petrol 171, 72 (2016). https://doi.org/10.1007/s00410-016-1284-2
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DOI: https://doi.org/10.1007/s00410-016-1284-2