Abstract
We present petrological investigations and mineral chemistry of several Tethyan ophiolites to reveal the occurrence, origin, and fate of water in podiform chromitites. The results show that clinopyroxene and olivine in chromitites have H2O contents of 801–366 and 53–17 ppm, respectively. The highest water contents of olivine occur in massive chromitite and the lowest always in the clinopyroxenebearing ores because much of the available hydrous fluids was taken up by the clinopyroxene during crystallization. The major and trace elemental and Li isotopic compositions of clinopyroxene associated with chromite and olivine in podiform chromitites indicate formation from a mixture of surface hydrous fluids on chromite grains and evolved melts from which olivine crystallized. The hydrous fluids initially originated from dehydration of a subducting slab as revealed by Li isotopic compositions of clinopyroxene and olivine in the chromitites. High fluid/rock ratios facilitated concentration of chromite to form chromitite, suppressing crystallization of olivine. The hydrous fluids that were collected on the chromite grain surface during crystallization allowed chromite grains to rise via decreasing density in the form of bubbles, thus promoting their gathering and concentration. The fate of these hydrous fluids depends on ambient physical and chemical conditions. Mostly they hydrate adjacent olivine grains in the chromitite or penetrate the surrounding dunite envelope. In some cases, the fluids dissolve into silicate melts to produce water-bearing clinopyroxene and/or hydrous minerals, such as amphibole, or infiltrate silicate and chromite grains to form inclusions, which may exsolve later in the form of mineral lamellae. Our investigations provide direct natural evidence for the presence and importance of water in the formation and evolution of chromite deposits, as inferred by earlier experimental studies.
Funding
This research was financially supported by National Natural Science Foundation of China (91755205 and 41772055), the State Key Laboratory of Lithospheric Evolution (201701), and Youth Innovation Promotion Association, Chinese Academy of Sciences (2016067).
References cited
Ahmed, A.H., and Arai, S. (2002) Unexpectedly high-PGE chromitite from the deeper mantle section of the northern Oman ophiolite and its tectonic implications. Contributions to Mineralogy and Petrology, 143, 263–278.10.1007/s00410-002-0347-8Search in Google Scholar
Akizawa, N., Arai, S., Tamura, A., Uesugi, J., and Python, M. (2011) Crustal diopsidites from the northern Oman ophiolite: evidence for hydrothermal circulation through suboceanic Moho. Journal of Mineralogical and Petrological Sciences, 106, 261–266.10.2465/jmps.110621bSearch in Google Scholar
Anders, E., and Grevesse, N. (1989) Abundances of the elements: meteoritic and solar. Geochimica et Cosmochimica Acta, 53, 197–214.10.1016/0016-7037(89)90286-XSearch in Google Scholar
Arai, S. (2013) Conversion of low-pressure chromitites to ultra-high-pressure chromitites by deep recycling: A good inference. Earth and Planetary Science Letters, 379, 81–87.10.1016/j.epsl.2013.08.006Search in Google Scholar
Arai, S., and Miura, M. (2016) Formation and modification of chromitites in the mantle. Lithos, 264, 277–295.10.1016/j.lithos.2016.08.039Search in Google Scholar
Arai, S., Matsukage, K., Isobe, E., and Vysotskiy, S. (1997) Concentration of incompatible elements in oceanic mantle: effect of melt/wall interaction in stagnant or failed conduits within peridotite. Geochimica et Cosmochimica Acta, 61, 671–675.10.1016/S0016-7037(96)00389-4Search in Google Scholar
Avcı, E., Uysal, I., Akmaz, R.M., and Saka, S. (2017) Ophiolitic chromitites from the Kızılyüksek area of the Pozantı-Karsantı ophiolite (Adana, southern Turkey): Implication for crystallization from a fractionated boninitic melt. Ore Geology Reviews, 90, 166–183.10.1016/j.oregeorev.2016.08.033Search in Google Scholar
Bai, Y., Su, B.X., Xiao, Y., Chen, C., Cui, M.M., He, X.Q., Qin, L.P., and Charlier, B. (2019) Diffusion-driven chromium isotope fractionation in minerals of ultramafic cumulates: elemental and isotopic evidence from the Stillwater Complex. Geochimica et Cosmochimica Acta, 263, 167–181.10.1016/j.gca.2019.07.052Search in Google Scholar
Ballhaus, C. (1998) Origin of podiform chromite deposits by magma mingling. Earth and Planetary Science Letters, 156, 185–193.10.1016/S0012-821X(98)00005-3Search in Google Scholar
Ballhaus, C., Fonseca, R.I.O.C., Kirchenbaur, M., and Zirner, A. (2015) Spheroidal textures in igneous rocks—Textural consequences of H2O saturation in basaltic melts. Geochimica et Cosmochimica Acta, 167, 241-252.10.1016/j.gca.2015.07.029Search in Google Scholar
Bell, D.R., Ihinger, P.D., and Rossman, G.R. (1995) Quantitative analysis of trace OH in garnet and pyroxenes. American Mineralogist, 80, 465–474.10.2138/am-1995-5-607Search in Google Scholar
Borisova, A., Ceuleneer, G., Kamenetsky, V., Arai, S., Béjina, F., Bindeman, I., Polvé, M., de Parseval, P., Aigouy, T., and Pokrovski, G. (2012) A new view on the petrogenesis of the Oman ophiolite chromitites from microanalyses of chromite-hosted inclusions. Journal of Petrology, 53, 2411–2440.10.1093/petrology/egs054Search in Google Scholar
Boudier, F., and Coleman, R.G. (1981) Cross section through the peridotite in the Samail ophiolite, southeastern Oman Mountains. Journal of Geophysical Research: Solid Earth, 86, 2573–2592.10.1029/JB086iB04p02573Search in Google Scholar
Boudreau, A. (1999) Fluid fluxing of cumulates: the JM reef and associated rocks of the Stillwater Complex, Montana. Journal of Petrology, 40, 755–772.10.1093/petroj/40.5.755Search in Google Scholar
Chen, C., Su, B.X., Uysal, I., Avcı, E., Zhang, P.F., Xiao, Y., and He, Y.S. (2015) Iron isotopic constraints on the origin of peridotite and chromitite in the Kızıldağ ophiolite, southern Turkey. Chemical Geology, 417, 115–124.10.1016/j.chemgeo.2015.10.001Search in Google Scholar
Chen, C., Su, B.X., Xiao, Y., Pang, K.N., Robinson, P.T., Uysal, İ., Lin, W., Qin, K.Z., Avcı, E., and Kapsiotis, A. (2019) Intermediate chromitite in Kızıldağ ophiolite (SE Turkey) formed during subduction initiation in Neo-Tethys. Ore Geology Reviews, 104, 88–100.10.1016/j.oregeorev.2018.10.004Search in Google Scholar
Dilek, Y., and Furnes, H. (2009) Structure and geochemistry of Tethyan ophiolites and their petrogenesis in subduction rollback systems. Lithos, 113, 1–20.10.1016/j.lithos.2009.04.022Search in Google Scholar
González-Jiménez, J.M., Griffin, W.L., Proenza, J.A., Gervilla, F., O’Reilly, S.Y., Akbulut, M., Pearson, N.J., and Arai, S. (2014). Chromitites in ophiolites: How, where, when, why? Part II. The crystallization of chromitites. Lithos, 189, 140–158.10.1016/j.lithos.2013.09.008Search in Google Scholar
Irvine, T.N. (1977) Chromite crystallization in the join Mg2SiO4–CaMgSi2O6– CaAl2Si2O8–MgCr2O4–SiO2. Carnegie Institution of Washington, Yearbook, 76, 465–472.Search in Google Scholar
Jannessary, M.R., Melcher, F., Lodziak, J., and Meisel, T.C. (2012) Review of platinum-group element distribution and mineralogy in chromitite ores from southern Iran. Ore Geology Reviews, 48, 278–305.10.1016/j.oregeorev.2012.05.001Search in Google Scholar
Johan, Z., Martin, R.F., and Ettler, V. (2017) Fluids are bound to be involved in the formation of ophiolitic chromite deposits. European Journal of Mineralogy, 29, 543–555.10.1127/ejm/2017/0029-2648Search in Google Scholar
Kapsiotis, A., Economou-Eliopoulos, M., Zheng, H., Su, B.X., Lenaz, D., Jing, J.J., Antonelou, A., Velicogna, M., and Xia, B. (2019) Refractory chromitites recovered from the Eretria mine, East Othris massif (Greece): Implications for metallogeny and deformation of chromitites within the lithospheric mantle portion of a forearc-type ophiolite. Geochemistry, 79, 130–152.10.1016/j.geoch.2018.12.003Search in Google Scholar
Keppler, H., and Bolfan-Casanova, N. (2006) Thermodynamics of water solubility and partitioning. Reviews in Mineralogy and Geochemistry, 62, 193–230.10.1515/9781501509476-013Search in Google Scholar
Kohn, S.C., and Grant, K.J. (2006) The partitioning of water between nominally anhydrous minerals and silicate melts. Reviews in Mineralogy and Geochemistry, 62, 231–241.10.1515/9781501509476-014Search in Google Scholar
Lago, B.L., Rabinowicz, M., and Nicolas, A. (1982) Podiform chromitite ore bodies: a genetic model. Journal of Petrology, 23, 103–125.10.1093/petrology/23.1.103Search in Google Scholar
Liang, Z., Xiao, Y., Thakurta, J., Su, B.X., Chen, C., Bai, Y., and Sakyi, P.A. (2018) Exsolution lamellae in olivine grains of dunite units from different types of maficutramafic complexes. Acta Geologica Sinica, 92, 586–599.10.1111/1755-6724.13544Search in Google Scholar
Liu, X., Su, B.X., Bai, Y., Chen, C., Xiao, Y., Liang, Z., Yang, S.H., Peng, Q.S., Su, B.C., and Liu, B. (2018). Ca-enrichment characteristics of parental magmas of chromitite in ophiolite: inference from mineral inclusions. Earth Science 43, 1038–1050 (in Chinese with English abstract).Search in Google Scholar
Lorand, J.P., and Ceuleneer, G. (1989) Silicate and base-metal sulfide inclusions in chromites from the Maqsad area (Oman ophiolite, Gulf of Oman): a model for entrapment. Lithos, 22, 173–190.10.1016/0024-4937(89)90054-6Search in Google Scholar
Matveev, S., and Ballhaus, C. (2002) Role of water in the origin of podiform chromitite deposits. Earth and Planetary Science Letters, 203, 235–243.10.1016/S0012-821X(02)00860-9Search in Google Scholar
Melcher, F., Grum, W., Simon, G., Thalhammer, T.V., and Stumpfl, E.F. (1997) Petrogenesis of the ophiolitic giant chromite deposits of Kempirsai, Kazakhstan: a study of solid and fluid inclusions in chromite. Journal of Petrology, 38, 1419–1458.10.1093/petroj/38.10.1419Search in Google Scholar
Miura, M., Arai, S., Ahmed, A.H., Mizukami, M., Okuno, M., and Yamamoto, S. (2012) Podiform chromitite classification revisited: a comparison of discordant and concordant chromitite pods from Wadi Hilti, northern Oman ophiolite. Journal of Asian Earth Sciences, 59, 52–61.10.1016/j.jseaes.2012.05.008Search in Google Scholar
Nicholson, D.M., and Mathez, E.A. (1991) Petrogenesis of the Merensky Reef in the Rustenburg section of the Bushveld Complex. Contributions to Mineralogy and Petrology, 107, 293–309.10.1007/BF00325100Search in Google Scholar
Pagé, P., and Barnes, S.J. (2009) Using trace elements in chromites to constrain the origin of podiform chromitites in the Thetford Mines ophiolite, Québec, Canada. Economic Geology, 104, 997–1018.10.2113/econgeo.104.7.997Search in Google Scholar
Plank, T., Kelley, K.A., Zimmer, M.M., Hauri, E.H., and Wallace, P.J. (2013) Why do mafic arc magmas contain ~4 wt% water on average? Earth and Planetary Science Letters, 364, 168–179.10.1016/j.epsl.2012.11.044Search in Google Scholar
Python, M., Ceuleneer, G., Ishida, Y., Barrat, J.A., and Arai, S. (2007) Oman diopsidites: a new lithology diagnostic of very high temperature hydrothermal circulation in mantle peridotite below oceanic spreading centres. Earth and Planetary Science Letters, 255, 289–305.10.1016/j.epsl.2006.12.030Search in Google Scholar
Rassios, A., and Smith, A.G. (2000). Constraints on the formation and emplacement age of western Greek ophiolites (Vourinos, Pindos, and Othris) inferred from deformation structures in peridotites. Special Papers-Geological Society of America, 473–484.10.1130/0-8137-2349-3.473Search in Google Scholar
Robinson, P.T., Bai, W.J., Malpas, J., Yang, J.S., Zhou, M.F., Fang, Q.S., Hu, X.F., Cameron, S., and Staudigel, H. (2004) Ultra-high pressure minerals in the Luobusa ophiolite, Tibet, and their tectonic implications. Geological Society London Special Publication, 226, 247–271.10.1144/GSL.SP.2004.226.01.14Search in Google Scholar
Roeder, P.L., and Reynolds, I. (1991) Crystallization of chromite and chromium solubility in basaltic melts. Journal of Petrology, 32, 909–934.10.1093/petrology/32.5.909Search in Google Scholar
Rollinson, H., and Adetunji, J. (2015) The geochemistry and oxidation state of podiform chromitites from the mantle section of the Oman ophiolite: a review. Gondwana Research, 27, 543–554.10.1016/j.gr.2013.07.013Search in Google Scholar
Rollinson, H., Mameri, L., and Barry, T. (2018) Polymineralic inclusions in mantle chromitites from the Oman ophiolite indicate a highly magnesian parental melt. Lithos, 310-311, 381–391.10.1016/j.lithos.2018.04.024Search in Google Scholar
Saka, S., Uysal, I., Akmaz, R.M., Kaliwoda, M., and Hochleitner, R. (2014) The effects of partial melting, melt-mantle interaction and fractionation on ophiolite generation: constraints from the Late Cretaceous Pozanti-Karsanti Ophiolite, southern Turkey. Lithos, 202-203, 300–316.10.1016/j.lithos.2014.05.027Search in Google Scholar
Schiano, P., Clocchiatti, R., Lorand, J.P., Massare, D., Deloule, E., and Chaussidon, M. (1997) Primitive basaltic melts included in podiform chromites from the Oman ophiolite. Earth and Planetary Science Letters, 146, 489–497.10.1016/S0012-821X(96)00254-3Search in Google Scholar
Shimizu, H., and Okamoto, A. (2016) The roles of fluid transport and surface reaction in reaction-induced fracturing, with implications for the development of mesh textures in serpentinites. Contributions to Mineralogy and Petrology, 171, 73.10.1007/s00410-016-1288-ySearch in Google Scholar
Sobolev, A.V., and Chaussidon, M. (1996) H2O concentrations in primary melts from supra-subduction zones and mid-ocean ridges: implications for H2O storage and recycling in the mantle. Earth and Planetary Science Letters, 137, 45–55.10.1016/0012-821X(95)00203-OSearch in Google Scholar
Su, B.X., Teng, F.Z., Hu, Y., Shi, R.D., Zhou, M.F., Zhu, B., Liu, F., Gong, X.H., Huang, Q.S., Xiao, Y., Chen, C., and He, Y.S. (2015a) Iron and magnesium isotope fractionation in oceanic lithosphere and sub-arc mantle: perspectives from ophiolites. Earth and Planetary Science Letters, 430, 523–532.10.1016/j.epsl.2015.08.020Search in Google Scholar
Su, B.X., Gu, X.Y., Deloule, E., Zhang, H.F., Li, Q.L., Li, X.H., Vigier, N., Tang, Y.J., Tang, G.Q., Liu, Y., Brewer, A., Mao, Q., and Ma, Y.G. (2015b) Potential orthopyroxene, clinopyroxene and olivine reference materials for in situ lithium isotope determination. Geostandards and Geoanalytical Research, 39, 357–369.10.1111/j.1751-908X.2014.00313.xSearch in Google Scholar
Su, B.X., Zhou, M.F., and Robinson, P.T. (2016) Extremely large fractionation of Li isotopes in chromitite-bearing mantle sequence. Scientific Reports, 6, 22370.10.1038/srep22370Search in Google Scholar PubMed PubMed Central
Su, B.X., Chen, C., Pang, K.N., Sakyi, P.A., Uysal, I., Avcı, E., and Zhang, P.F. (2018) Melt penetration in oceanic lithosphere: Li isotope records from the Pozantı-Karsantı ophiolite in southern Turkey. Journal of Petrology, 59, 191–205.10.1093/petrology/egy023Search in Google Scholar
Su, B.X., Zhou, M.F., Jing, J.J., Robinson, P.T., Chen, C., Xiao, Y., Liu, X., Shi, R.D., Lenaz, D., and Hu, Y. (2019) Distinctive melt activity and chromite mineralization in Luobusa and Purang ophiolites, southern Tibet: constraints from trace element compositions of chromite and olivine. Science Bulletin, 64, 108–121.10.1016/j.scib.2018.12.018Search in Google Scholar
Thayer, T.P. (1969) Gravity differentiation and magmatic re-emplacement of podiform chromite deposits. Economic Geology Monograph, 4, 132–146.Search in Google Scholar
Tomascak, P.B., Magna, T., and Dohmen, R. (2016) Advances in Lithium Isotope Geochemistry. Springer.10.1007/978-3-319-01430-2Search in Google Scholar
Withers, A.C. (2013) On the use of unpolarized infrared spectroscopy for quantitative analysis of absorbing species in birefringent crystals. American Mineralogist, 98, 689–697.10.2138/am.2013.4316Search in Google Scholar
Xia, Q.K., Hao, Y., Li, P., Deloule, E., Coltorti, M., Dallai, L., Yang, X., and Feng, M. (2010) Low water content of the Cenozoic lithospheric mantle beneath the eastern part of the North China Craton. Journal of Geophysical Research: Solid Earth, 115(B7).10.1029/2009JB006694Search in Google Scholar
Xiao, Y., Teng, F.Z., Su, B.X., Hu, Y., Zhou, M.F., Zhu, B., Shi, R.D., Huang, Q.S., Gong, X.H., and He, Y.S. (2016) Iron and magnesium isotopic constraints on the origin of chemical heterogeneity in podiform chromitite from the Luobusa ophiolite, Tibet. Geochemistry, Geophysics, Geosystems, 17, 940–953.10.1002/2015GC006223Search in Google Scholar
Xiong, F., Yang, J., Dilek, Y., and Wang, C. (2017) Nanoscale diopside and spinel exsolution in olivine from dunite of the Tethyan ophiolites, southwestern Turkey: Implications for the multi-stage process. Journal of Nanoscience and Nanotechnology, 17, 6587–6596.10.1166/jnn.2017.14506Search in Google Scholar
Yamamoto, S., Komiya, T., Hirose, K., and Maruyama, S. (2009) Coesite and clinopyroxene exsolution lamellae in chromites: in-situ ultrahigh-pressure evidence from podiform chromitites in the Luobusa ophiolite, southern Tibet. Lithos, 109, 314–322.10.1016/j.lithos.2008.05.003Search in Google Scholar
Yang, J.S., Dobrzhinetskaya, L., Bai, W.J., Fang, Q.S., Robinson, P.T., Zhang, J., and Green, H.W. (2007) Diamond-and coesite-bearing chromitites from the Luobusa ophiolite, Tibet. Geology, 35, 875–878.10.1130/G23766A.1Search in Google Scholar
Yu, M., Wang, Q., and Yang, J. S. (2019) Fabrics and water contents of peridotites in the Neotethyan Luobusa ophiolite, Southern Tibet: Implications for mantle recycling in supra-subduction zones. Journal of the Geological Society, 176, 975–991.10.1144/jgs2018-152Search in Google Scholar
Zaeimnia, F., Arai, S., and Mirmohammadi, M. (2017) Na-rich character of metasomatic/metamorphic fluids inferred from preiswerkite in chromitite pods of the Khoy ophiolite in Iran: Role of chromitites as capsules of trapped fluids. Lithos, 268-271, 351–363.10.1016/j.lithos.2016.11.021Search in Google Scholar
Zhang, P.F., Zhou, M.F., Liu, Q.Y., Malpas, J., Robinson, P.T., and He, Y.S. (2019) Modification of mantle rocks by plastic flow below spreading centers: Fe isotopic and fabric evidence from the Luobusa ophiolite, Tibet. Geochimica et Cosmochimica Acta, 253, 84–110.10.1016/j.gca.2019.03.008Search in Google Scholar
Zhou, M.F., Robinson, P.T., Malpas, J., and Li, Z. (1996) Podiform chromitites from the Luobusa ophiolite (southern Tibet): implications for melt-rock interaction and chromite segregation. Journal of Petrology, 37, 3–21.10.1093/petrology/37.1.3Search in Google Scholar
© 2020 Walter de Gruyter GmbH, Berlin/Boston
