Abstract
Phosphorus-rich olivine (P2O5 > 1 wt%) is a mineral that has been reported only in a few terrestrial and extraterrestrial occurrences. Previous investigations suggest that P-rich olivine mainly forms through rapid crystallization from high-temperature P-rich melts. Here, we report a new occurrence of P-rich olivine in an ungrouped carbonaceous chondrite Dar al Gani (DaG) 978. The P-rich olivine in DaG 978 occurs as lath-shaped grains surrounding low-Ca pyroxene and olivine grains. The lath-shaped olivine shows a large variation in P2O5 (0–5.5 wt%). The P-rich olivine grains occur in a chondrule fragment and is closely associated with chlorapatite, merrillite, FeNi metal, and troilite.Tiny Cr-rich hercynite is present as inclusions within the P-rich olivine. The lath-shaped texture and the association with Cr-rich hercynite indicates that the P-rich olivine in DaG 978 formed by replacing low-Ca pyroxene precursor by a P-rich fluid during a thermal event, rather than by crystallization from a high-temperature melt. The large variation of P2O5 within olivine grains on micrometer-scale indicates a disequilibrium formation process of the P-rich olivine. The occurrence of P-rich olivine in DaG 978 reveals a new formation mechanism of P-rich olivine.
Acknowledgments
This study is financially supported by Natural Science Foundation of China (Grant No. 41373065) and the Fundamental Research Funds for the Central Universities. We thank Run-Lian Pang for helpful discussions. We appreciate the comments from Kimberly Tait and John Beckett and the editorial effort from Associate Editor E. Watson.
References cited
Agrell, S.O., Charnley, N.R., and Chinner, G.A. (1998) Phosphoran olivine from Pine Canyon, Piute Co., Utah. Mineralogical Magazine, 62, 265–269.10.1180/002646198547620Search in Google Scholar
Anderson, A.T., and Greenland, L.P. (1969) Phosphorus fractionation diagram as a quantitative indicator of crystallization differentiation of basaltic liquids. Geochimica et Cosmochimica Acta, 33, 493–505.10.1016/0016-7037(69)90129-XSearch in Google Scholar
Boesenberg, J.S., and Hewins, R.H. (2010) An experimental investigation into the metastable formation of phosphoran olivine and pyroxene. Geochimica et Cosmochimica Acta, 74, 1923–1941.10.1016/j.gca.2009.12.008Search in Google Scholar
Brearley, A.J. and Krot, A.N. (2013) Metasomatism in the early solar system: the record from chondritic meteorites. In Harlov D. E. and Austrheim H. Berlin, Eds., Metasomatism and the chemical transformation of rock, Lecture notes in Earth System Sciences. Springer-Verlag. pp. 659–789.10.1007/978-3-642-28394-9_15Search in Google Scholar
Brunet, F., and Chazot, G. (2001) Partitioning of phosphorus between olivine, clinopyroxene and silicate glass in a spinel lherzolite xenolith from Yemen. Chemical Geology, 176, 51–72.10.1016/S0009-2541(00)00351-XSearch in Google Scholar
Buseck, P.R. (1977) Pallasite meteorites—Mineralogy, petrology and geochemistry. Geochimica et Cosmochimica Acta, 41, 711–740.10.1016/0016-7037(77)90044-8Search in Google Scholar
Buseck, P.R., and Clark, J. (1984) Zaisho—A pallasite containing pyroxene and phosphoran olivine. Mineralogical Magazine, 48, 229–235.10.1180/minmag.1984.048.347.06Search in Google Scholar
Choe, W.H., Huber, H., Rubin, A.E., Kallemeyn, G.W., and Wasson, J.T. (2010) Compositions and taxonomy of 15 unusual carbonaceous chondrites. Meteoritics and Planetary Science, 45, 531–554.10.1111/j.1945-5100.2010.01039.xSearch in Google Scholar
Fowler-Gerace, N.A., and Tait, K.T. (2015) Phosphoran olivine overgrowth: Implications for multiple impacts to the Main Group pallasite parent body. American Mineralogist, 100, 2043–2052.10.2138/am-2015-5344Search in Google Scholar
Goodrich, C.A. (1984) Phosphoran pyroxene and olivine in silicate inclusions in natural iron-carbon alloy, Disko Island, Greenland. Geochimica et Cosmochimica Acta, 48, 2769–2771.10.1016/0016-7037(84)90322-3Search in Google Scholar
Hsu, W., Guan, Y., Hua, X., Wang, Y., Leshin, L.A., and Sharp, T.G. (2006) Aqueous alteration of opaque assemblages in the Ningqiang carbonaceous chondrite: Evidence from oxygen isotopes. Earth and Planetary Science Letters, 243, 107–144.10.1016/j.epsl.2005.12.021Search in Google Scholar
Jones, R.H. (1990) Petrology and mineralogy of type II, FeO-rich chondrules in Semarkona (LL3.0): Origin by closed-system fractional crystallization, with evidence for supercooling. Geochimica et Cosmochimica Acta, 54, 1785–1802.10.1016/0016-7037(90)90408-DSearch in Google Scholar
Jones, R.H., and Rubie, D.C. (1993) Thermal histories of CO3 chondrites: Application of olivine diffusion modelling to parent body metamorphism. Earth and Planetary Science Letters, 106, 73–86.10.1016/0012-821X(91)90064-OSearch in Google Scholar
Klein-BenDavid, O., Pettke, T., and Kessel, R. (2011) Chromium mobility in hydrous fluids at upper mantle conditions. Lithos, 125, 122–130.10.1016/j.lithos.2011.02.002Search in Google Scholar
Krot, A.N., Petaev, M.I., and Bland, P.A. (2004) Multiple formation mechanisms of ferrous olivine in CV3 carbonaceous chondrites during fluid-assisted metamorphism. Antarctic Meteorite Research, 17, 154–172.Search in Google Scholar
McCanta, M.C., Beckett, J.R., and Stolper, E.M. (2016) Correlations and zoning patterns of phosphorus and chromium in olivine from H chondrites and the LL chondrite Semarkona. Meteoritics and Planetary Science, 51, 520–546.10.1111/maps.12604Search in Google Scholar
Milman-Barris, M.S., Beckett, J.R., Baker, M.B., Hofmann, A.E., Morgan, Z., Crowley, M.R., Vielzeuf, D., and Stolper, E. (2008) Zoning of phosphorus in igneous olivine. Contributions to Mineralogy and Petrology, 155, 739–765.10.1007/s00410-007-0268-7Search 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
Russell, S.S., Zipfel, J., Folco, L., Jones, R., Grady, M.M., McCoy, T., and Grossman, J.N. (2003) The Meteoritical Bulletin, No. 87. Meteoritics and Planetary Science, 38, A189–A248.10.1111/j.1945-5100.2003.tb00328.xSearch in Google Scholar
Schneider, P., Tropper, P., and Kaindl, R. (2013) The formation of phosphoran olivine and stanfieldite from the pyrometamorphic breakdown of apatite in slags from a prehistoric ritual immolation site (Goldbichl, Igls, Tyrol, Austria). Mineralogy and Petrology, 107, 327–340.10.1007/s00710-012-0255-1Search in Google Scholar
Sonzogni, Y., Devouard, B., Provost, A., and Devidal, J.-L. (2009) Olivine-hosted melt inclusions in the Brahin pallasite. In Meteoritics and Planetary Science Supplement, p. 5070, 72nd Annual Meeting of the Meteoritical Society, Nancy, France.Search in Google Scholar
Tropper, P., Recheis, A., and Konzett, J. (2004) Pyrometamorphic formation of phosphorus-rich olivines in partially molten metapelitic gneisses from a prehistoric sacrificial burning site (Ötz Valley, Tyrol, Austria). European Journal of Mineralogy, 16, 631–640.10.1127/0935-1221/2004/0016-0631Search in Google Scholar
Wang, Y., Hua, X., and Hsu, W. (2007) Petrogenesis of opaque assemblages in the Ningqiang carbonaceous chondrite. Science in China Series D: Earth Sciences, 50, 886–896.10.1007/s11430-007-0006-zSearch in Google Scholar
Wasson, J.T., Lange, D.E., and Francis, C.A. (1999) Massive chromite in the Brenham pallasite and the fractionation of Cr during the crystallization of asteroidal cores. Geochimica et Cosmochimica Acta, 63, 1219–1232.10.1016/S0016-7037(98)00307-XSearch in Google Scholar
Watenphul, A., Schmidt, C., and Jahn, S. (2014) Cr(III) solubility in aqueous fluids at high pressures and temperatures. Geochimica et Cosmochimica Acta, 126, 212–227.10.1016/j.gca.2013.10.054Search in Google Scholar
Watson, E.B., Cherniak, D.J., and Holycross, M.E. (2015) Diffusion of phosphorus in olivine and molten basalt. American Mineralogist, 100, 2053–2065.10.2138/am-2015-5416Search in Google Scholar
Zanda, B., Bourot-Denise, M., Perron, C., and Hewins, R.H. (1994) Origin and metamorphic redistribution of silicon, chromium, and phosphorus in the metal of chondrites. Science, 265, 1846–1849.10.1126/science.265.5180.1846Search in Google Scholar PubMed
Zhang, A.C., and Yurimoto, H. (2013) Petrography and mineralogy of the ungrouped type 3 carbonaceous chondrite Dar al Gani 978. Meteoritics and Planetary Science, 48, 1651–1677.10.1111/maps.12154Search in Google Scholar
Zhang, A.C., Itoh, S., Sakamoto, N., Wang, R.C., and Yurimoto, H. (2014) Origins of Al-rich chondrules: Clues from a compound Al-rich chondrule in the Dar al Gani 978 carbonaceous chondrite. Geochimica et Cosmochimica Acta, 130, 78–92.10.1016/j.gca.2013.12.026Search in Google Scholar
Zhang, A.C., Li, Q.L., Yurimoto, H., Sakamoto, N., Li, X.H., Hu, S., Lin, Y.T., and Wang, R.C. (2016) Young asteroidal fluid activity revealed by absolute age from apatite in carbonaceous chondrite. Nature Communications, 7, 12844, 10.1038/ncomms12844.Search in Google Scholar PubMed PubMed Central
© 2017 by Walter de Gruyter Berlin/Boston
