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地质学报  2005 

西藏罗布莎蛇绿岩的Os―Ir―Ru合金及其中玻安岩质包体的研究

Keywords: Os-Ir-Ru合金,玻安岩,包裹体,蛇绿岩,西藏

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Abstract:

笔者最近在西藏罗布莎蛇绿岩块豆荚状铬铁矿的Os-Ir-Ru合金中,发现自形晶的玻安岩质的包体群。按它们的主要化学成分,其相当于高Ca玻安岩。18个包体的平均化学成分为:MgO=20.15%,Al2O3=8.99%,SiO2=54.42%,CaO=11.15%,FeO=2.81%,Na2O=1.00%,并含有少量NiO和Cr2O3。由于该包体粒径较小(<20μm),用Raman激光光谱仪测定,它们具有尖晶石、磁铁矿和辉石等Raman谱,由此确定存在玻安岩质尖晶石。结合已发现的共生矿物,如硅金红石、八面体Mg-Fe硅酸盐等高压矿物,有理由推断玻安岩质尖晶石形成于400~670km深的过渡带。玻安岩质辉石是尖晶石降压相变产物。根据罗布莎铬铁矿高Cr特点,罗布莎铬铁矿的形成与该玻安岩质熔体有关。玻安岩质尖晶石、铬铁矿和Os-Ir-Ru合金三者统一形成于过渡带或地幔深部,由地幔柱快速上升搬运这些矿物到地幔浅部。

References

[1]  白文吉,周美付,Robinson P T,et al. 2000.西藏罗布莎豆荚状铬铁矿、金刚石及伴生矿物成因.北京:地震出版社,1~98.
[2]  白文吉,杨经绥,方青松,等.2003.西藏蛇绿岩中不寻常的地幔矿物群.中国地质,30(2):144~150.
[3]  杨风英,康志勤,刘淑春.1981.蛇纹石八面体假象及其成因初步讨论.矿物学报,(1)::52~54.
[4]  Auge T. 1988. Platinum group minerals in the Tiebaghi and Veurinos ophiolite complex: genetic implications. Canadian Mineralogist,26: 177~192.
[5]  Bai Wenji, Zhou Meifu, Robinson P T, et al. 2000. Origin of podiform chromitite, diamond and their associated minerals at Luobusa, Tibet. Beijing: Seismological Publishing House, 1~ 98(in Chinese with English abstract).
[6]  Bai Wenji, Yang Jingsui, Fang Qingsong, et al. 2001. Study on a storehouse of ultrahigh pressure mantle minerals-podiform chromite deposits. Earth Sci. Frontiers 8 (3): 111 ~ 121 (in Chinese with English abstract).
[7]  Bai Wenji, Yang Jingsui, Fang Qingsong, et al. 2004. Chemical compositions of alloys from podiform chromitites in the Luobusa ophiolite, Tibet. Acta Geologica Sinica, 78 (5): 675~682 (in Chinese with English abstract).
[8]  Bird J M. 1979. Origin of Josephinite. Geochemical Journal, 13:41 ~55.
[9]  Bird J M, Bassett W A. 1980. Evidence of a deep mantle history in Terrenstria osmium-iridium ruthenium alloys. Journal of Geophysical Research, 85 (1310): 5461~5470.
[10]  Brenker F E, Meibom A, kobett F. 2003. On the formation of peridotite-derived Os-rich PGE alloys. American Mineralogist,88: 1731~1740.
[11]  Dick H J B, Gillete H. 1976. Josephinite-specimens from the core? A discussion. Earth and Planetary Science Letters, 31: 308~311.
[12]  Dick H J B, Bullen T. 1984. Chromian spinel as a petrogenetic indicator in abyssal and Alpine-type peridotites and spatially associated lavas. Contribution to Mineralogy and Ptrology, 86:54~76.
[13]  Eckstrend O K. 1975. The Dumont serpentinite: a model for control of nickeliferous opaque mineral assemblages by alteration reactions in ultramafic rocks. Economic Geology and the Bulletin of the Society of Economic Geologist, 70: 183~201.
[14]  Falloon T J,Green D H, McCulloch M T. 1989. Petrogenesis of high-Mg and associated lavas from the North Tonga trench. In:Crawford A J,eds. Boninites and Related Rocks. Unaya,Hyman,London, 357~395.
[15]  Finger L W, Hazen R M. 1991. Crystal chemistry of six-coordinated silicon: a key to understanding the Earth\'s deep interior. Acta Crystalloger, B47: 561~580.
[16]  Garuti G, Zaccarini F. 1997. In situ alteration of platinum-group minerals at low temperature: evidence from serpentinized and weathered chromitite of the Vourinos complex. Greece. Canadian Mineralogist, 35: 611 ~ 626.
[17]  Harris D C, Cabri L J. 1991. Nomenclature of platinum group element alloys: review and revision. Canadian Mineralogist, 29: 231 ~237.
[18]  Hazen K M, Downs K T, Finger L W. 1993. Crystal chemistry of ferromagnesian silicate spinels: Evidence for Mg-Si disorder.American Mineralogist, 78: 1320~ 1323.
[19]  Melcher F, Grum W, Simon G, et al. 1997. Petrogenesis of the ophiolitic giant chromite deposits of Kempirsai, Kazakhstan. A study of solid and fluid inclusions in chromite. Jourmal of Petrology, 38:1419 ~ 1458.
[20]  Stockman H W, Hlana P F. 1984. Platinum-group minerals in Alpine chromitites form southweastern Oregon. Economic Geology, 79:491~508.
[21]  Talkington K W, Watkinson D H, Whitaker P T, et al. 1984.Platinum-group minerals and other solid inclusions in chromite of ophiolitic complexes: occurrence and petrological. Tschermaks Mineralogische und Petrographische Mittilungen, 32: 285~301.
[22]  Zhou M F. 1995. Petrogenesis of the podiform chromitite in the Luobusa ophiolites, Southern Tibet. Unpublished PHD thesis,Dalhousie University.
[23]  白文吉,杨经绥,方青松,等.2001.寻找超高压矿物的储存库--豆荚状铬铁矿.地学前缘,8(3):111~121.
[24]  白文吉,杨经绥,方青松,等.2004.西藏罗布莎蛇绿岩豆荚状铬铁矿石中的合金成分.地质学报,78(5):675~682.
[25]  Arai S. 1992. Chemistry of chromian spinel in volcanic rocks as a potential guide to magma chemistry. Mineral Mag. , 56:173 ~184.
[26]  Bai Wenji, Robinson Paul T, Fang Qingsong, et al. 2000. The PGE and base-metal alloys in the podiform chromites of the Luobusa ophiolite, southern Tibet. Canadian Mineralogist, 38:585 ~598.
[27]  Bai Wenji, Yang Jingsui, Fang Qingsong, et al. 2003. An unusual mantle mineral group in ophiolites of Tibet. Geology in China, 30(2): 144~150 (in Chinese with English abstract).
[28]  Ballhaus C. 1998. Origin of podiform chromite deposits by magma mingling. Earth and Planetary Science Letters, 156: 185~193.
[29]  Bird J M, Weathers M S. 1975. Josephinite: specimens from the Earth core? Earth and Planetary Science Letters, 28: 51~64.
[30]  Bird J M, Meibom A, Frei R, Nagler T H. 1999. Osmium and lead isotopes of rare Os-Ir-Ru minerals: derivation from the coremantle boundary region? Earth and Planetary Science Letters,170: 83~92.
[31]  Bohlen S R, Boettecher A L. 1982. The quartz coesite transformation: a pressure determination and effects of other components. Journal of Geophysical Research, 87: 7073~7078.
[32]  Cameron W E. 1985. Petrology and origin of primitive lavas from the Troodos ophiolite. Contrib. Mineral Petrol. ,89: 239~255.
[33]  Chamberlain J A. 1965. Native metals in the Muskov intrusion.Canadian Journal of Earth Sciences, 2: 188~215.
[34]  Crawford A J, Falloon T J, Green D H. 1989. Classification,petrogenesis and tectonic setting of boninites. In: Crawford A J,ed. Boninite and Related Rocks, 1 ~ 49.
[35]  Dick H J B. 1974. Terrestrial nickel-iron from the Josephine peridotite, its geological occurrence, associations and origin.Earth and Planetary Science Letters, 24: 291~ 298.
[36]  Enami M, Zang Q. 1990. Quartz pseudomorphs after coesite in eclogites from Shandong province, east China. American Mineralogist, 75: 381~386.
[37]  Falloon T J, Danyushevsky L V. 2000. Melting of refractory mantle at 1.5, 2 and 2.5 GPa under anhydrous and H2O-undersaturated conditions: Implications for the petrogenesis of high-Ca boninites and the influence of subduction components on mantle melting.Journal of Petrology, 41: 257~283.
[38]  Hirajima T, Ishiwatari A, Cong B, et al. 1990. Coesite from Mengzhong eclogite at Donghai county, northeastern Jiangsu province, China. Mineralogical Magazine, 54: 579~583.
[39]  Jonieson G S. 1905. On the natural iron-nickl alloy awaruite.American Journal of Science, 19: 413.
[40]  Matveev S, Ballhaus C. 2002. Role of water in the origin of podiform chromitite deposits. Earth and Planetary Science Letters, 203:235~243.
[41]  Ramdohr P. 1950. Uher Josephinite, Awarit, Souesite ihrer Eigenschaften. Entstehung und Paragenesis. Mineralogical Magazine, 12: 374.
[42]  Robinson P T, Bai W J, Malpas J, et al. 2004. Ultra-high pressure minerals in the Luobusa ophiobite, Tibet and their tectonic implications. in Aspects of the Tectonic Evolution of China.Geological Society, London, Special Publications, 226:247 ~271.
[43]  Yang Jingsui, Bai Wenji, Fang Qingsong. et al. 2003. Silicon-rutile ultra-high pressure mineral from ophiolits. Progress in Nature Science, 13 (7) :528~531.

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