Re-Os Isotopic Characteristics and Geological Significance of Mafic Rocks from the Xigaze Ophiolite,Tibet

doi:10.19657/j.geoscience.1000-8527.2022.06.06

Abstract

Abstract:

Petrology and elemental geochemistry of mafic rocks from the Xigaze ophiolite are studied so as to investigate the petrogenesis and source characteristics of the ophiolite. At the same time, Re-Os isotope geochemical constraints in formation mechanisms of the Yarlung Zangpo ophiolite is also explored. The result shows that the primitive mantle-normalized multi-element pattern of the mafic rocks is similar to the normal Mid-Ocean Ridge Basalt (N-MORB) with the characteristics of island arc. Combined with the characteristics of the trace elements and isotope, all of these are shown that the petrogenesis is related to subduction. The Xigaze ophiolite was formed in the SSZ environment far away from the continental crust, so it’s not contaminated by the continent crust during its development, also the alteration in Re-Os isotope systematics was not obvious. The reason of Re-Os isotopic characteristics with low Re, low Os and high ratios of ¹⁸⁷Os/¹⁸⁸Os for the mafic rocks is manifested by the source characteristics and the subduction. The multi-stage Tethyan subduction resulted in the mantle heterogeneity. During the subduction of Neo-Tethys, the mafic magma from the above-mentioned heterogeneous mantle went through the peridotite channel influenced by the early melts, leading to the Re-Os fractionation and amplifying the Os-isotope mismatch between the melt and residual mantle, that’s the petrogenesis of the Xigaze ophiolite.

Key words: petrogenesis, source characteristics, Re-Os isotope, Xigaze ophiolite

CLC Number:

P588.12
P597

LI Wenxia, ZHAO Zhidan, WANG Xiaoli, YAN Rong, LU Yuanfa. Re-Os Isotopic Characteristics and Geological Significance of Mafic Rocks from the Xigaze Ophiolite,Tibet[J]. Geoscience, 2022, 36(06): 1503-1512.

Figures/Tables 10

References 67

[1]	BARNES S J, NALDRETT A J, GORTON M P. The origin of the fractionation of platinum-group elements in terrestrial magmas[J]. Chemical Geology, 1985, 53(3/4):303-323.
[2]	SHIREY S B, WALKER R J. The Re-Os isotope system in cosmochemistry and high-temperature geochemistry[J]. Annual Review of Earth and Planetary Sciences, 1998, 26(1):423-500.
[3]	徐勇, 刘金高, 田功成, 等. 强亲铁元素高温地球化学与天体化学及研究进展[J]. 矿物岩石地球化学通报, 2019, 38(2):273-298.
[4]	COLTORTI M, BONADIMAN C, O’REILLY S Y, et al. Buo-yant ancient continental mantle embedded in oceanic lithosphere(Sal Island,Cape Verde Archipelago)[J]. Lithos, 2010, 120(1/2):223-233.
[5]	STANDISH J J, HART S R, BLUSZTAJN J, et al. Abyssal peridotite osmium isotopic compositions from Cr-spinel[J]. Geochemistry, Geophysics, Geosystems, 2002, 3(1):1-24.
[6]	LIU C Z, SNOW J E, HELLEBRAND E, et al. Ancient, highly heterogeneous mantle beneath Gakkel ridge,Arctic Ocean[J]. Nature, 2008, 452(7185):311-316.
[7]	BIZIMIS M, GRISELIN M, LASSITER J C, et al. Ancient recycled mantle lithosphere in the Hawaiian plume:Osmium-hafnium isotopic evidence from peridotite mantle xenoliths[J]. Earth and Planetary Science Letters, 2007, 257(1/2):259-273.
[8]	ALARD O, LUGUET A, PEARSON N J, et al. In situ Os isotopes in abyssal peridotites bridge the isotopic gap between MORBs and their source mantle[J]. Nature, 2005, 436(7053):1005-1008.
[9]	SHI R D, GRIFFIN W L, O’REILLY S Y, et al. Melt/mantle mixing produces podiform chromite deposits in ophiolites:Implications of Re-Os systematics in the Dongqiao Neo-tethyan ophiolite,northern Tibet[J]. Gondwana Research, 2012, 21(1):194-206.
[10]	HARVEY J, GANNOUN A, BURTON K W, et al. Unravelling the effects of melt depletion and secondary infiltration on mantle Re-Os isotopes beneath the French Massif Central[J]. Geochimica et Cosmochimica Acta, 2010, 74(1):293-320.
[11]	ZHANG C, LIU C Z, JI W B, et al. Heterogeneous sub-ridge mantle of the Neo-Tethys:Constraints from Re-Os isotope and HSE compositions of the Xigaze ophiolites[J]. Lithos, 2020,378-379:105819.
[12]	GANNOUN A, BURTON K W, PARKINSON I J, et al. The scale and origin of the osmium isotope variations in mid-ocean ridge basalts[J]. Earth and Planetary Science Letters, 2007, 259(3/4):541-556.
[13]	GONZÁLEZ-JIMÉNEZ J M, MARCHESI C, GRIFFIN W L, et al. Transfer of Os isotopic signatures from peridotite to chromitite in the subcontinental mantle:Insights from in situ analysis of platinum-group and base-metal minerals(Ojen peridotite massif,southern Spain)[J]. Lithos, 2013, 164/167:74-85.
[14]	ALDANMAZ E, SCHMIDT M W, GOURGAUD A, et al. Mid-ocean ridge and supra-subduction geochemical signatures in spinel-peridotites from the Neotethyan ophiolites in SW Turkey:implications for upper mantle melting processes[J]. Lithos, 2009, 113(3):691-708.
[15]	SERGEEV D S, DIJKSTRA A H, MEISEL T, et al. Traces of ancient mafic layers in the Tethys oceanic mantle[J]. Earth and Planetary Science Letters, 2014, 389(1):155-166.
[16]	SHI R D, ALARD O, ZHI X C, et al. Multiple events in the Neo-Tethyan oceanic upper mantle:Evidence from Ru-Os-Ir alloys in the Luobusa and Dongqiao ophiolitic podiform chromitites,Tibet[J]. Earth and Planetary Science Letters, 2007, 261(1/2):33-48.
[17]	NIU X L, YANG J S, DILEK Y, et al. Petrological and Os isotopic constraints on the origin of the Dongbo peridotite massif,Yarlung Zangbo Suture Zone,Western Tibet[J]. Journal of Asian Earth Sciences, 2015, 110:72-84.
[18]	LIU C Z, WU F Y, CHU Z Y, et al. Preservation of ancient Os isotope signatures in the Yungbwa ophiolite(southwestern Tibet)after subduction modification[J]. Journal of Asian Earth Sciences, 2012, 53(3):38-50.
[19]	XU Y, LIU J G, XIONG Q, et al. The complex life cycle of oceanic lithosphere:A study of Yarlung-Zangbo ophiolitic peridotites,Tibet[J]. Geochimica et Cosmochimica Acta, 2020, 277:175-191.
[20]	LIU T, WU F Y, LIU C Z, et al. Reconsideration of Neo-Tethys evolution constrained from the nature of the Dazhuqu ophiolitic mantle,Southern Tibet[J]. Contributions to Mineralogy and Petrology, 2019, 174:1-23.
[21]	史仁灯, 黄启帅, 刘德亮, 等. 古老大陆岩石圈地幔再循环与蛇绿岩中铬铁矿床成因[J]. 地质论评, 2012, 58(4):643-652.
[22]	许继峰, 王桂琴, 李杰, 等. 月球物质的Re-Os同位素组成研究:对月球后期增生历史的指示[J]. 地球化学, 2010, 39(2):142-148.
[23]	李杰, 张晶, 尹露. 地质样品的Re-Os同位素分析技术及存在的问题[J]. 矿物岩石地球化学通报, 2018, 37(2):342-349.
[24]	王希斌, 鲍佩声, 邓万明, 等. 西藏蛇绿岩[M]. 北京: 地质出版社, 1987:1-137.
[25]	朱弟成, 莫宣学, 王立全, 等. 新特提斯演化的热点与洋脊相互作用:西藏南部晚侏罗世—早白垩世岩浆作用推论[J]. 岩石学报, 2008, 24(2):225-237.
[26]	LIU T, WU F Y, ZHANG L L, et al. Zircon U-Pb geochronological constraints on rapid exhumation of the mantle peridotite of the Xigaze ophiolite, southern Tibet[J]. Chemical Geology, 2016, 443:67-86.
[27]	XIONG Q, GRIFFIN W L, ZHENG J P, et al. Southward trench migration at -130-120 Ma caused accretion of the Neo-Tethyan forearc lithosphere in Tibetan ophiolites[J]. Earth and Planetary Science Letters, 2016, 438:57-65.
[28]	ZHANG C, LIU C Z, WU F Y, et al. Geochemistry and geochronology of mafic rocks from the Luobusa ophiolite,South Tibet[J]. Lithos, 2016, 245:93-108.
[29]	吴福元, 刘传周, 张亮亮, 等. 雅鲁藏布蛇绿岩——事实与臆想[J]. 岩石学报, 2014, 30(2):293-325.
[30]	牛晓露, 赵志丹, 莫宣学, 等. 西藏日喀则地区德村—昂仁蛇绿岩内基性岩的元素与Sr-Nd-Pb同位素地球化学及其揭示的特提斯地幔域特征[J]. 岩石学报, 2006, 22(12):2875-2888.
[31]	MAHONEY J J, FREI R, TEJADA M L G, et al. Tracing the Indian Ocean mantle domain through time:Isotopic results from old west indian,east tethyan,and south pacific seafloor[J]. Journal of Petrology, 1998, 39(7):1285-1306.
[32]	ZHANG S Q, MAHONEY J J, MO X X, et al. Evidence for a widespread Tethyan upper mantle with Indian-Ocean-type isotopic characteristics[J]. Journal of Petrology, 2005, 46(4):829-858.
[33]	GAO S, LIU X M, YUAN H L, et al. Determination of forty two major and trace elements in USGS and NISTSRM glasses by laser ablation inductively coupled plasma mass spectrometry geostandards[J]. News Letter Journal of Geostandards and Geoanalysis, 2002, 26:191-196.
[34]	李文霞, 赵志丹, 朱弟成, 等. 西藏雅鲁藏布蛇绿岩形成构造环境的地球化学鉴别[J]. 岩石学报, 2012, 28(5):1663-1673.
[35]	李文霞, 赵志丹, 朱弟成, 等. 西藏日喀则地区雅鲁藏布蛇绿岩地球化学特征及其源区性质[J]. 现代地质, 2016, 30(2):294-302.
[36]	XU J F, SUZUKI K, XU Y G, et al. Os,Pb,and Nd isotope geochemistry of the Permian Emeishan continental flood basalts:Insights into the source of a large igneous province[J]. Geochimica et Cosmochimica Acta, 2007, 71(8):2104-2119.
[37]	BECKER H, HORAN M F, WALKER R J, et al. Highly siderophile element composition of the Earth’s primitive upper mantle:Constraints from new data on peridotite massifs and xenoliths[J]. Geochimica et Cosmochimica Acta, 2006, 70(17):4528-4550.
[38]	江琳, 支霞臣. 汉诺坝玄武岩Re-Os同位素地球化学——Re的挥发性丢失和壳-幔相互作用的证据[J]. 岩石学报, 2010, 26(4):1265-1276.
[39]	MEISEL T, WALKER R J, IRVING A J, et al. Osmium isotopic compositions of mantle xenoliths:a global perspective[J]. Geochimica et Cosmochimica Acta, 2001, 65:1311-1323.
[40]	EISELE J, SHARMA M, GALER SJG, et al. The role of sediment recycling in EM-I inferred from Os,Pb,Hf,Nd,Sr isotope and trace element systematics of the Pitcairn hotspot[J]. Earth and Planetary Science Letters, 2002, 196:197-212.
[41]	DEPAOLO D J. Neodymium isotopes in the Colorado Front Range and crust-mantle evolution in the Proterozoic[J]. Nature, 1981, 291:193-196.
[42]	张旗, 周德进. 一种新的洋壳类型及其动力学意义[J]. 科学通报, 1996, 41(11):1025-1027.
[43]	PEUCKER-EHRENBRINK B, HANGHOJ K, ATWOOD T, et al. Rhenium-osmium isotope systematics and platinum group element concentrations in oceanic crust[J]. Geology, 2012, 40(3):199-202.
[44]	WALKER R J, PRICHARD H M, ISHIWATARI A, et al. The osmium isotopic composition of convecting upper mantle deduced from ophiolite chromites[J]. Geochimica et Cosmochimica Acta, 2002, 66(2):329-345.
[45]	SHARMA M, PAPANASTASSIOU D A, WASSERBUG G J. The concentration and isotopic composition of osmium in the oceans[J]. Geochimica et Cosmochimica Acta, 1997, 61:3287-3299.
[46]	CHEN C, SHARMA M. High precision and high sensitivity measurements of osmium in seawater[J]. Analytical Chemistry, 2009, 81:5400-5406. DOI PMID
[47]	GANNOUN A, BURTON K W. High precision osmium elemental and isotope measurements of North Atlantic seawater[J]. Journal of Analytical Atomic Spectrometry, 2014, 29:2330-2342.
[48]	LEVASSEUR S, BIRCK J L, ALLÈGRE C J. Direct measurement of femtomoles of osmium and the ¹⁸⁷Os/¹⁸⁶Os ratio in seawater[J]. Science, 1998, 282(5387):272-274.
[49]	HOFMANN A W. Sampling mantle heterogeneity through oceanic basalts:Isotopes and trace elements[M]//CARLSON R W. The Mantle and Core,Treatise on Geochemistry. Amsterdam: Elsevier-Pergamon Scientific Press, 2004:61-101.
[50]	周金城, 蒋少涌, 王孝磊, 等. 东南沿海晚中生代镁铁质岩的Re-Os同位素组成[J]. 岩石学报, 2006, 22(2):407-413.
[51]	BOYNTON W V. Geochemistry of the rare earth elements:Meteorite studies[M]//HENDERSON P. Rare Earth Element Geochemistry. New York: Elsevier, 1984:63-114.
[52]	SUN S S, MCDONOUGH W F. Chemical and isotopic systema-tics of oceanic basalts:implications for mantle composition and processes[J]. Geological Society, London, Special Publications, 1989, 42(1):313-345.
[53]	史仁灯, 支霞臣, 陈雷, 等. Re-Os同位素体系在蛇绿岩应用研究中的进展[J]. 岩石学报, 2006, 22(6):1685-1695.
[54]	DILEK Y, FURNES H. Ophiolite genesis and global tectonics:Geochemical and tectonic fingerprinting of ancient oceanic lithosphere[J]. Geological Society of America Bulletin, 2011, 123(3/4):387-411.
[55]	PEARCE J A. Geochemical fingerprinting of oceanic basalts with applications to ophiolite classification and the search for Archean oceanic crust[J]. Lithos, 2008, 100(1/2/3/4):14-48.
[56]	XIONG Q, XU Y, GONZÁLEZ-JIMÉNEZ J M, et al. Sulfide in dunite channels reflects long-distance reactive migration of mid-ocean-ridge melts from mantle source to crust:A Re-Os isotopic perspective[J]. Earth and Planetary Science Letters, 2020, 531:115969.
[57]	TSURU A, WALKER R J, KONTINEN A, et al. Re-Os isotopic systematics of the 1.95 Ga Jormua Ophiolite Complex,northeastern Finland[J]. Chemical Geology, 2000, 164(1/2):123-141.
[58]	DALE C W, LUGUET A, MACPHERSON C G, et al. Extreme platinum-group element fractionation and variable Os isotope compositions in Philippine Sea Plate basalts:Tracing mantle source heterogeneity[J]. Chemical Geology, 2008, 248(3):213-238.
[59]	HANSON G N. Geochemical evolution of the suboceanic mantle[J]. Journal of the Geological Society, 1977, 134(2):235-253.
[60]	ALLÈGRE C J, TURCOTTE D L. Implications of a two component marble-cake mantle[J]. Nature, 1986, 323(323):123-127.
[61]	ESCRIG S, CAPMAS F, DUPRÉ B, et al. Osmium isotopic constraints on the nature of the DUPAL anomaly from Indian mid-ocean-ridge basalts[J]. Nature, 2004, 431(7004):59-63.
[62]	SCHIANO P, BIRCK J L, ALLÈGRE C J. Osmium-strontium-neodymium-lead isotopic covariations in mid-ocean ridge basalt glasses and the heterogeneity of the upper mantle[J]. Earth and Planetary Science Letters, 1997, 150(3/4):363-379.
[63]	TANG G J, WYMAN D A, WANG Q, et al. Asthenosphere-lithosphere interaction triggered by a slab window during ridge subduction:Trace element and Sr-Nd-Hf-Os isotopic evidence from Late Carboniferous tholeiites in the western Junggar area(NW China)[J]. Earth and Planetary Science Letters, 2012, 329/330(5):84-96.
[64]	BECKER H. Re-Os fractionation in eclogites and blueschists and the implications for recycling of oceanic crust into the mantle[J]. Earth and Planetary Science Letters, 2000, 177(3/4):287-300.
[65]	DALE C W, GANNOUN A, BURTON K W, et al. Rhenium-osmium isotope and elemental behaviour during subduction of oceanic crust and the implications for mantle recycling[J]. Earth and Planetary Science Letters, 2007, 253(1/2):211-225.
[66]	HÉBERT R, BEZARD R, GUILMETTE C, et al. The Indus-Yarlung Zangbo ophiolites from Nanga Parbat to Namche Barwa syntaxes,southern Tibet:First synthesis of petrology,geochemi-stry,and geochronology with incidences on geodynamic reconstructions of Neo-Tethys[J]. Gondwana Research, 2012, 22(2):377-397.
[67]	XIONG Q, GRIFFIN W L, ZHENG J P, et al. Two-layered oceanic lithospheric mantle in a Tibetan ophiolite produced by episodic subduction of Tethyan slabs[J]. Geochemistry, Geophysics, Geosystems, 2017, 18:1189-1213.

样品号	Re含量/ (ng/g)	2σ	Os含量/ (ng/g)	2σ	¹⁸⁷Os/¹⁸⁸Os	2σ	¹⁸⁷Re/¹⁸⁸Os	2σ	Re/Os	(¹⁸⁷Os/ ¹⁸⁸Os )₀	γ_Os (125 Ma)	t_DM/Ga
RK1010	0.005 8	0.490 17	0.006 7	0.011 29	0.289 86	0.001 20	4.3	0.360 79	0.865 67	0.280 968	125.2	2.45
RK1012	0.038 5	0.607 31	0.005 6	0.006 58	0.501 49	0.001 36	34.9	0.552 87	6.875 00	0.429 318	289.7	0.65
RK1014	0.003 6	0.428 86	0.019 3	0.046 65	0.345 64	0.000 83	0.9	0.110 31	0.186 53	0.343 779	168.6	21.73
RK1015	0.015 4	0.865 26	0.004 3	0.006 31	0.367 30	0.001 59	17.9	1.004 79	3.581 40	0.330 283	185.4	0.82
RK1018	0.011 6	0.885 91	0.007 8	0.012 38	0.343 92	0.000 96	7.4	0.563 38	1.487 18	0.328 617	167.2	1.83
RK1035	0.056 8	1.596 73	0.003 0	0.004 29	0.671 63	0.003 22	98.7	2.781 76	18.933 33	0.467 521	421.9	0.33
RK1044	0.009 4	0.302 23	0.020 3	0.030 56	0.179 54	0.000 44	2.2	0.072 22	0.463 05	0.174 990	39.5	1.71
RK1047	0.016 7	1.389 64	0.009 2	0.015 74	0.246 53	0.000 90	8.9	0.736 06	1.815 22	0.228 125	91.6	0.83

样品号	Re含量/ (ng/g)	2σ	Os含量/ (ng/g)	2σ	¹⁸⁷Os/¹⁸⁸Os	2σ	¹⁸⁷Re/¹⁸⁸Os	2σ	Re/Os	(¹⁸⁷Os/ ¹⁸⁸Os )₀	γ_Os (125 Ma)	t_DM/Ga
RK1010	0.005 8	0.490 17	0.006 7	0.011 29	0.289 86	0.001 20	4.3	0.360 79	0.865 67	0.280 968	125.2	2.45
RK1012	0.038 5	0.607 31	0.005 6	0.006 58	0.501 49	0.001 36	34.9	0.552 87	6.875 00	0.429 318	289.7	0.65
RK1014	0.003 6	0.428 86	0.019 3	0.046 65	0.345 64	0.000 83	0.9	0.110 31	0.186 53	0.343 779	168.6	21.73
RK1015	0.015 4	0.865 26	0.004 3	0.006 31	0.367 30	0.001 59	17.9	1.004 79	3.581 40	0.330 283	185.4	0.82
RK1018	0.011 6	0.885 91	0.007 8	0.012 38	0.343 92	0.000 96	7.4	0.563 38	1.487 18	0.328 617	167.2	1.83
RK1035	0.056 8	1.596 73	0.003 0	0.004 29	0.671 63	0.003 22	98.7	2.781 76	18.933 33	0.467 521	421.9	0.33
RK1044	0.009 4	0.302 23	0.020 3	0.030 56	0.179 54	0.000 44	2.2	0.072 22	0.463 05	0.174 990	39.5	1.71
RK1047	0.016 7	1.389 64	0.009 2	0.015 74	0.246 53	0.000 90	8.9	0.736 06	1.815 22	0.228 125	91.6	0.83