Geochemical characteristics, genesis and geological significance of Quedingbu-Luqu peridotites in the Xigaze area, middle Yarlung Zangbo suture zone

doi:10.13745/j.esf.sf.2023.9.42

Abstract

Abstract:

The Xigaze ophiolite is a significant feature of the Yarlung Zangbo suture zone, yet its origin and tectonic setting have been subject to debate. This study focuses on the ophiolite in the Quedingbu-Luqu area of Xigaze. Through detailed field geology, petrology, mineral chemistry, and petrochemistry analyses, it is established that the ophiolite predominantly comprises harzburgite with minor occurrences of gabbro, diabase, and basal. A comparison between the Quedingbu and Luqu harzburgite reveals differences in olivine composition, with the former exhibiting lower Fo values, and variations in Al₂O₃ and Cr₂O₃ content in orthopyroxene. Moreover, clinopyroxene displays higher Al₂O₃ and Cr^# values, while spinel shows lower Cr^# and TiO₂ contents. The Quedingbu-Luqu harzburgite is characterized by high MgO content and low Al₂O₃, CaO, and TiO₂ contents. The total rare earth element (REE) contents range from 0.17×10^-6 to 1.63×10^-6, lower than those of primitive and depleted mantle. Luqu harzburgite exhibits high LREE/HREE and (La/Yb)_N ratios, while Quedingbu harzburgite shows lower values. Luqu harzburgite displays a LREE-enriched U-type REE distribution pattern, whereas Quedingbu harzburgite exhibits a LREE-depleted left dipping REE distribution pattern. The large ion lithophile elements Rb and Ba in Luqu harzburgite are higher than in Quedingbu harzburgite, while K and Sr are lower. The Quedingbu-Luqu harzburgite likely originates from spinel lherzolite in the mantle. The mineral chemistry and whole-rock geochemical characteristics of Quedingbu-Luqu harzburgite resemble that of deep-sea mantle peridotite. Quedingbu harzburgite represents residue from 10% to 15% partial melting, while Luqu harzburgite represents residue from 20% to 25% partial melting. The formation of Quedingbu-Luqu harzburgite occurred in a slow to ultra-slow extensional ocean ridge environment. The diversity of the Xigaze ophiolite is closely tied to the degree of partial melting in the source and subsequent melt/fluid metasomatism.

Key words: Yarlung Zangbo suture zone, Quedingbu-Luqu ophiolite, peridotite, petrogenesis

CLC Number:

CHEN Guochao, ZHANG Xiaofei, PEI Xianzhi, PEI Lei, LI Zuochen, LIU Chengjun, LI Ruibao. Geochemical characteristics, genesis and geological significance of Quedingbu-Luqu peridotites in the Xigaze area, middle Yarlung Zangbo suture zone[J]. Earth Science Frontiers, 2024, 31(3): 1-19.

Figures/Tables 17

References 100

[1]	WAKABAYASHI J, GHATAK A, BASU A R. Suprasubduction-zone ophiolite generation, emplacement, and initiation of subduction: a perspective from geochemistry, metamorphism, geochronology, and regional geology[J]. Geological Society of America Bulletin, 2010, 122(9/10): 1548-1568.
[2]	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.
[3]	DILEK Y, FURNES H. Ophiolites and their origins[J]. Elements, 2014, 10(2): 93-100.
[4]	张进, 邓晋福, 肖庆辉, 等. 蛇绿岩研究的最新进展[J]. 地质通报, 2012, 31(1): 1-12.
[5]	PEARCE J A. Immobile element fingerprinting of ophiolites[J]. Elements, 2014, 10(2): 101-108.
[6]	MIYASHIRO A. Classification, characteristics, and origin of ophiolites[J]. Journal of Geology, 1975, 83(2): 249-281.
[7]	PEARCE J A, LIPPARD S J, ROBERTS S. Characteristics and tectonic significance of supra-subduction zone ophiolites[J]. Geological Society, London, Special Publications, 1984, 16: 77-94.
[8]	ZHOU M F, ROBINSON P T, MALPAS J, et al. Melt/mantle interaction and melt evolution in the Sartohay high-Al chromite deposits of the Dalabute ophiolite (NW China)[J]. Journal of Asian Earth sciences, 2001, 19(4): 517-534.
[9]	郑建平, 熊庆, 赵伊, 等. 俯冲带橄榄岩及其记录的壳幔相互作用[J]. 中国科学: 地球科学, 2019, 49(7): 1037-1058.
[10]	王希斌, 鲍佩声, 肖序常, 等. 西藏蛇绿岩[M]. 北京: 地质出版社, 1987.
[11]	王成善, 刘志飞, 何政伟. 西藏南部早白垩世雅鲁藏布江古蛇绿岩的识别与讨论[J]. 地质学报, 1999, 73(1): 7-14.
[12]	YIN A, HARRISON T M. Geologic evolution of the Himalayan-Tibetan orogen[J]. Annual Review of Earth and Planetary Sciences, 2000, 28: 211-280.
[13]	许志琴, 杨经绥, 侯增谦, 等. 青藏高原大陆动力学研究若干进展[J]. 中国地质, 2016, 43(1): 1-42.
[14]	张旗. 日喀则蛇绿岩研究中的几个问题[J]. 岩石学报, 2015, 31(1): 37-46.
[15]	MILLER C, THÖNI M, FRANK W, et al. Geochemistry and tectonomagmatic affinity of the Yungbwa ophiolite, SW Tibet[J]. Lithos, 2003, 66(3/4): 155-172.
[16]	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.
[17]	肖文交, 敖松坚, 杨磊, 等. 喜马拉雅汇聚带结构-属性解剖及印度-欧亚大陆最终拼贴格局[J]. 中国科学: 地球科学, 2017, 47(6): 631-656.
[18]	ZHANG L L, LIU C Z, WU F Y, et al. Sr-Nd-Hf isotopes of the intrusive rocks in the Cretaceous Xigaze ophiolite, southern Tibet: constraints on its formation setting[J]. Lithos, 2016, 258/259: 133-148.
[19]	LIU C Z, ZHANG C, YANG L Y, et al. Formation of gabbronorites in the Purang ophiolite (SW Tibet) through melting of hydrothermally altered mantle along a detachment fault[J]. Lithos, 2014, 205: 127-141.
[20]	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.
[21]	LIU T, WU F Y, LIU C Z, et al. Variably evolved gabbroic intrusions within the Xigaze ophiolite (Tibet): new insights into the origin of ophiolite diversity[J]. Contributions to Mineralogy and Petrology, 2018, 173: 91.
[22]	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: 23.
[23]	ZHANG C, LIU C Z, WU F Y, et al. Ultra-refractory mantle domains in the Luqu ophiolite (Tibet): petrology and tectonic setting[J]. Lithos, 2017, 286/287: 252-263.
[24]	陈根文, 夏斌, 钟志洪, 等. 西藏得几蛇绿岩体中玻安岩的地球化学特征及其地质意义[J]. 矿物学报, 2003, 23(1): 91-96.
[25]	DAI J G, WANG C S, POLAT A, et al. Rapid forearc spreading between 130 and 120 Ma: evidence from geochronology and geochemistry of the Xigaze ophiolite, southern Tibet[J]. Lithos, 2013, 172/173: 1-16.
[26]	李源, 李瑞保, 董天赐, 等. 日喀则蛇绿岩白马让岩体的穹窿形结构及构造意义[J]. 科学通报, 2016, 61(25): 2823-2833.
[27]	XIONG F H, YANG J S, ROBINSON P T, et al. Petrology and geochemistry of peridotites and podiform chromitite in the Xigaze ophiolite, Tibet: implications for a suprasubduction zone origin[J]. Journal of Asian Earth Sciences, 2017, 146(15): 56-75.
[28]	肖序常, 王军. 青藏高原构造演化及隆升的简要评述[J]. 地质论述, 1998, 44(4): 372-381.
[29]	刘小汉, 琚宜太, 韦利杰, 等. 再论雅鲁藏布江缝合带构造模型[J]. 中国科学D辑: 地球科学, 2009, 29(4): 448-463.
[30]	BEZARD R, HÉBERT R, WANG C S, et al. Petrology and geochemistry of the Xiugugabu ophiolitic massif, western Yarlung Zangbo suture zone[J]. Lithos, 2011, 125(1/2): 347-367.
[31]	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, geochemistry, and geochronology with incidences on geodynamic reconstructions of Neo-Tethys[J]. Gondwana Research, 2012, 22(2): 377-397.
[32]	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.
[33]	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.
[34]	王冉, 夏斌, 周国庆, 等. 西藏吉定蛇绿岩中辉长岩SHRIMP锆石U-Pb年龄[J]. 科学通报, 2006, 51(1): 114-117.
[35]	夏斌, 李建峰, 刘立文, 等. 西藏桑桑蛇绿岩辉绿岩SHRIMP锆石U-Pb年龄: 对特提斯洋盆发育的年代学制约[J]. 地球化学, 2008, 37(4): 399-403.
[36]	李建峰, 夏斌, 刘立文, 等. 西藏群让蛇绿岩辉长岩SHRIMP锆石U-Pb年龄及地质意义[J]. 大地构造与成矿学, 2009, 33(2): 294-298.
[37]	BAO P S, SU L, WANG J, et al. Study on the tectonic setting for the ophiolites in Xigaze, Tibet[J]. Acta Geologica Sinica (English Edition), 2013, 87(2): 395-42.
[38]	杨胜标, 李源, 杨经绥, 等. 西藏日喀则白马让蛇绿岩: 亚洲大陆边缘的小洋盆[J]. 岩石学报, 2017, 33(12): 3766-3782.
[39]	MALPAS J, ZHOU M F, ROBINSON P T, et al. Geochemical and geochronological constraints on the origin and emplacement of the YarlungZangbo ophiolites, Southern Tibet[J]. Geological Society, London, Special Publications, 2003, 218: 191-206.
[40]	杨艳. 日喀则雄玛岩浆岩岩石学与年代学特征[D]. 北京: 中国地质大学(北京), 2017.
[41]	徐向珍, 杨经绥, 熊发挥, 等. 西藏雅鲁藏布江缝合带中段日喀则地幔橄榄岩中发现金刚石等异常矿物[J]. 地质学报, 2018, 92(7): 1389-1400.
[42]	MO X X, NIU Y L, DONG G C, et al. Contribution of syncollisional felsic magmatism to continental crust growth: a case study of the Paleogene Linzizong volcanic succession in southern Tibet[J]. Chemical Geology, 2008, 250(1/2/3/4): 49-67.
[43]	WAN X Q, WANG L, WANG C S, et al. Discovery and significance of Cretaceous fossils from the Xigaze forearc basin, Tibet[J]. Journal of Asian Earth Sciences, 1997, 16(2): 217-223.
[44]	DAI J G, WANG C S, ZHU D C, et al. Multi-stage volcanic activities and geodynamic evolution of the Lhasa terrane during the Cretaceous: insights from the Xigaze forearc basin[J]. Lithos, 2015, 218/219: 127-140.
[45]	ZIABREV S V, AITCHISON J C, ABRAJEVITCH A V, et al. Precise radiolarian age constraints on the timing of ophiolite generation and sedimentation in the Dazhuqu terrane, Yarlung-Tsangpo suture zone, Tibet[J]. Journal of the Geological Society, 2003, 160(4): 591-599.
[46]	AN W, HU X M, GARZANTI E, et al. Xigaze forearc basin revisited (South Tibet): provenance changes and origin of the Xigaze ophiolite[J]. Geological Society of America Bulletin, 2014, 126(11/12): 1595-1613.
[47]	GIRARDEAU J, MERCIER J C C, YOU G Z. Origin of the Xigaze ophiolite, Yarlung Zangbo suture zone, southern Tibet[J]. Tectonophysics, 1985, 119(1): 407-433.
[48]	MA Z L, LI G W, ZHENG Y F, et al. Variable exhumation history between the central and eastern Xigaze fore-arc basin, South Tibet: implications for underthrusting Indian slab dynamics[J]. Terra Nova, 2021, 35(5): 441-454.
[49]	ZHAO M S, CHEN Y X, ZHENG Y F. Geochemical evidence for forearc metasomatism of peridotite in the Xigaze ophiolite during subduction initiation in Neo-Tethyan Ocean, south to Tibet[J]. Lithos, 2021, 380/381: 105896.
[50]	MCDONOUGH W F, SUN S. The composition of the Earth[J]. Chemical Geology, 1995, 120(3/4): 223-253.
[51]	NIU Y L. Mantle melting and melt extraction processes beneath ocean ridges: evidence from abyssal peridotites[J]. Journal of Petrology, 1997, 38(8): 1047-1074.
[52]	NIU Y L. Bulk-rock major and trace element compositions of abyssal peridotites: implications for mantle melting, melt extraction and post-melting processes beneath mid-ocean ridges[J]. Journal of Petrology, 2004, 45(12): 2423-2458.
[53]	PARKINSON I J, PEARCE J A. Peridotites from the Izu-Bonin-Mariana Forearc(ODP Leg 125), evidence for mantle melting and melt-mantle interaction in a supra-subduction zone setting[J]. Journal of Petrology, 1998, 39(9): 1577-1618.
[54]	SUN S S, MCDONOUGH W F. Chemical and isotopic systematics of oceanic basalts: implications for mantle composition and processes[J]. Geological Society, London, Special Publications, 1989, 42: 313-345.
[55]	SALTERS V, STRACKE A. Composition of the depleted mantle[J]. Geochemistry, Geophysics, Geosystems, 2004, 5(5): Q05B07.
[56]	冯光英, 杨经绥, 熊发挥, 等. 雅鲁藏布江蛇绿岩带西段错不扎地幔橄榄岩组成特征及岩石成因[J]. 中国地质, 2015, 42(5): 1337-1353.
[57]	BOYNTON W V. Geochemistry of the rare earth elements: meteorite studies[M]//HENDERSON P. Rare earth element geochemistry. Amsterdam: Elservier, 1984: 63-114.
[58]	HELLEBRAND E, SNOW J E, MÜHE R. Mantle melting beneath Gakkel Ridge(Arctic Ocean): abyssal peridotite spinel compositions[J]. Chemical Geology, 2002, 182(2/3/4): 227-235.
[59]	UYSAL Í, ERSOY E Y, KARSLI O, et al. Coexistence of abyssal and ultra-depleted SSZ type mantle peridotites in a neo-Tethyan ophiolite in SW Turkey: constraints from mineral composition, whole-rock geochemistry(major-trace-REE-PGE), and Re-Os isotope systematics[J]. Lithos, 2012, 132: 50-69.
[60]	BEZARD R, HÉBERT R, WANG C S, et al. Petrology and geochemistry of the Xiugugabu ophiolitic massif, western Yarlung Zangbo suture zone[J]. Lithos, 2011, 125(1/2): 347-367.
[61]	来盛民, 杨经绥, 熊发挥, 等. 西藏雅鲁藏布江缝合带东段泽当地幔橄榄岩特征及其意义[J]. 岩石学报, 2015, 31(12): 3629-3649.
[62]	KRISHNAKANTA SINGH A. Petrology and geochemistry of abyssal peridotites from the Manipur Ophiolite Complex, Indo-Myanmar Orogenic Belt, Northeast India: implication for melt generation in mid-oceanic ridge environment[J]. Journal of Asian Earth Sciences, 2013, 66: 258-276.
[63]	JAGOUTZ E, PALME H, BADDENHAUSEN H, et al. The abundances of major, minor and trace elements in the earth’s mantle as derived from primitive ultramafic nodules[M]//Proceedings of the 10th lunar and planetary science conference. New York: Pergamon Press, 1979: 2031-2050.
[64]	DICK H J B, BULLEN T. Chromian spinel as a petrogenetic indicator in abyssal and alpine-type peridotites and spatially associated lavas[J]. Contributions to Mineralogy and Petrology, 1984, 86(1): 54-76.
[65]	KOSTOPOULOS D K. Melting of the shallow upper mantle: a new perspective[J]. Journal of Petrology, 1991, 32(4): 671-699.
[66]	JAQUES A L, GREEN D H. Anhydrous melting of peridotite at 0-15 kb pressure and the genesis of tholeiitic basalts[J]. Contributions to Mineralogy and Petrology, 1980, 73(3): 287-310.
[67]	BARNES S J, ROEDER P L. The range of spinel compositions in terrestrial mafic and ultramafic rocks[J]. Journal of Petrology, 2001, 42(12): 2279-2302.
[68]	DICK H J B, NATLAND J H C. Late stage melt evolution and transport in the shallow mantle beneath the East Pacific Rise[J]. Proceedings of the Ocean Drilling Program, Scientific Results, 1996, 147: 103-134.
[69]	张利, 杨经绥, 刘飞, 等. 南公珠错地幔橄榄岩: 雅鲁藏布江缝合带西段一个典型的大洋地幔橄榄岩[J]. 岩石学报, 2016, 32(12): 3649-3672.
[70]	TAMURA A, ARAI S. Harzburgite-dunite-orthopyroxenite suite as a record of supra-subduction zone setting for the Oman ophiolite mantle[J]. Lithos, 2006, 90(1/2): 43-56.
[71]	PEARCE J A, BARKER P F, EDWARDS S J, et al. Geochemistry and tectonic significance of peridotites from the South Sandwich arc-basin system, South Atlantic[J]. Contributions to Mineralogy and Petrology, 2000, 139(1): 36-53.
[72]	OZAWA K. Melting and melt segregation in the mantle wedge above a subduction zone: evidence from the chromite-bearing peridotites of the Miyamori ophiolite complex, northeastern Japan[J]. Journal of Petrology, 1994, 35(3): 647-678.
[73]	FREY F A, SUEN J C, STOCKMAN H W. The Ronda high temperature peridotite: geochemistry and petrogenesis[J]. Geochimica et Cosmochimica Acta, 1985, 49(11): 2469-2491.
[74]	连东洋, 杨经绥, 熊发挥, 等. 雅鲁藏布江蛇绿岩带西段达机翁地幔橄榄岩组成特征及其形成环境分析[J]. 岩石学报, 2014, 30(8): 2164-2184.
[75]	DUPUIS C, HÉBERT R, DUBOIS-CÔTÉ V, et al. Petrology and geochemistry of mafic rocks from mélange and flysch units adjacent to the Yarlung Zangbo Suture Zone, southern Tibet[J]. Chemical Geology, 2005, 214(3/4): 287-308.
[76]	ZHENG Y F. Subduction zone geochemistry[J]. Geoscience Frontiers, 2019, 10: 1223-1254.
[77]	KELEMEN P B, DICK H J, QUICK J E. Formation of harzburgite by pervasive melt/rock reaction in the upper mantle[J]. Nature, 1992, 358: 635-641.
[78]	KELEMEN P B, SHIMIZU N, SALTERS V J M. Extraction of mid-ocean-ridge basalt from the upwelling mantle by focused flow of melt in dunite channels[J]. Nature, 1995, 375: 747-753.
[79]	ZHOU M F, ROBINSON P T, MALPAS J, et al. REE and PGE geochemical constraints on the formation of dunite in the Luobusa ophiolite, Southern Tibet[J]. Journal of Petrology, 2005, 46(3): 615-639.
[80]	ZHENG Y F, CHEN R X, ZHAO Z F. Chemical geodynamics of continental subduction-zone metamorphism: insights from studies of the Chinese Continental Scientific Drilling (CCSD) core samples[J]. Tectonophysics, 2009, 475(2): 327-358.
[81]	CRAWFORD A J, BECCALUVA L, SERRI G. Tectono-magmatic evolution of the West Philippine-Mariana region and the origin of boninites[J]. Earth and Planetary Science Letters, 1981, 54(2): 346-356.
[82]	ROSPABÉ M, CEULENEER G, BENOIT M, et al. Origin of the dunitic mantle-crust transition zone in the Oman ophiolite: the interplay between percolating magmas and high-temperature hydrous fluids[J]. Geology, 2017, 45(5): 471-474.
[83]	DAI J G, WANG C S, STERN R J, et al. Forearc magmatic evolution during subduction initiation: insights from an early cretaceous Tibetan ophiolite and comparison with the Izu-Bonin-Mariana forearc[J]. Geological Society of America Bulletin, 2021, 133(3/4): 753-776.
[84]	TIAN L R, ZHENG J P, XIONG Q, et al. Xigaze ophiolite (South Tibet) records complex melt-fluid-peridotite interaction in the crust-mantle transition zone beneath oceanic slow-ultraslow spreading centers[J]. Lithos, 2022, 414/415: 106623.
[85]	LI Y, LI R B, ROBINSON P T, et al. Detachment faulting in the Xigaze ophiolite southern Tibet: new constraints on its origin and implications[J]. Gondwana Research, 2021, 94: 44-55.
[86]	BARNES S J. Chromite in komatiites, 1. Magmatic controls on crystallization and composition[J]. Journal of Petrology, 1998, 39(10): 1689-1720.
[87]	TAKAHASHI E. Origin of basaltic magmas: implications from peridotite melting experiments and an olivine fractionation model[J]. Bulletin of the Volcanological Society of Japan, 1986, 30: S17-S40.
[88]	PAGÉ P, BÉDARD J H, SCHROETTER J M, et al. Mantle petrology and mineralogy of the Thetford Mines ophiolite complex[J]. Lithos, 2008, 100(1/2/3/4): 255-292.
[89]	HATTORI K H, GUILLOT S. Geochemical character of serpentinites associated with high- to ultrahigh-pressure metamorphic rocks in the Alps, Cuba, and the Himalayas: recycling of elements in subduction zones[J]. Geochemistry, Geophysics, Geosystems, 2007, 8(9): 1-27.
[90]	HUANG W T, VAN HINSBERGEN D J J, MAFFIONE M, et al. Lower Cretaceous Xigaze ophiolites formed in the Gangdese forearc: evidence from paleomagnetism, sediment provenance, and stratigraphy[J]. Earth and Planetary Science Letters, 2015, 415: 142-153.
[91]	CHEN G W, XIA B. Platinum-group elemental geochemistry of mafic and ultramafic rocks from the Xigaze ophiolite, southern Tibet[J]. Journal of Asian Earth Sciences, 2008, 32(5/6): 406-422.
[92]	陈根文, 刘睿, 夏斌, 等. 西藏吉定蛇绿岩地球化学特征及其构造指示意义[J]. 岩石学报, 2015, 31(9): 2495-2507.
[93]	夏斌, 王冉, 陈根文. 西藏仁布蛇绿岩壳层熔岩的岩石地球化学及成因[J]. 高校地质学报, 2003, 9(4): 638-647.
[94]	李强, 夏斌, 温珍河, 等. 西藏日喀则蛇绿岩构造环境再讨论[J]. 矿物岩石地球化学通报, 2015, 34(5): 993-1006.
[95]	XIA B, CHEN G W, WANG R, et al. Seamount volcanism associated with the Xigaze ophiolite, southern Tibet[J]. Journal of Asian Earth Sciences, 2008, 32(5/6): 396-405.
[96]	VERMA S P. Seawater alteration effects on ⁸⁷Sr/⁸⁶Sr, K, Rb, Cs, Ba and Sr in oceanic igneous rocks[J]. Chemical Geology, 1981, 34(1/2): 81-89.
[97]	WHATTAM S A, STERN R J. The “subduction initiation rule”: a key for linking ophiolites, intra-oceanic forearcs, and subduction initiation[J]. Contributions to Mineralogy and Petrology, 2011, 162(5): 1031-1045.
[98]	STERN R J, REAGAN M, ISHIZUKA O, et al. To understand subduction initiation, study forearc crust: to understand forearc crust, study ophiolites[J]. Lithosphere, 2012, 4(6): 469-483.
[99]	肖庆辉, 李廷栋, 潘桂棠, 等. 识别洋陆转换的岩石学思路: 洋内弧与初始俯冲的识别[J]. 中国地质, 2016, 43(3): 721-737.
[100]	NOWELL G M, KEMPTON P D, NOBLE S R, et al. High precision Hf isotope measurements of MORB and OIB by thermal ionisation mass spectrometry: insights into the depleted mantle[J]. Chemical Geology, 1998, 149(3/4): 211-233.

测点	w_B/%												Fo
测点	SiO₂	TiO₂	Al₂O₃	Cr₂O₃	FeO	MnO	MgO	NiO	CaO	Na₂O	K₂O	Total	Fo
PM802-19-1-1	40.68	0.00	0.05	0.03	8.88	0.14	50.32	0.25	0.08	0.03	0.00	100.20	91.08
PM802-19-1-2	40.19	0.05	0.01	0.03	8.91	0.15	48.15	0.34	0.13	0.04	0.00	98.01	90.68
PM802-19-1-3	40.70	0.00	0.02	0.06	9.01	0.15	48.73	0.25	0.07	0.00	0.00	98.97	90.69
PM802-19-1-4	41.07	0.01	0.01	0.00	9.04	0.09	50.11	0.30	0.04	0.02	0.00	100.68	90.89
PM802-19-1-5	40.98	0.02	0.02	0.02	8.72	0.12	48.94	0.27	0.12	0.03	0.00	99.23	90.99

测点	w_B/%												Fo
测点	SiO₂	TiO₂	Al₂O₃	Cr₂O₃	FeO	MnO	MgO	NiO	CaO	Na₂O	K₂O	Total	Fo
PM802-19-1-1	40.68	0.00	0.05	0.03	8.88	0.14	50.32	0.25	0.08	0.03	0.00	100.20	91.08
PM802-19-1-2	40.19	0.05	0.01	0.03	8.91	0.15	48.15	0.34	0.13	0.04	0.00	98.01	90.68
PM802-19-1-3	40.70	0.00	0.02	0.06	9.01	0.15	48.73	0.25	0.07	0.00	0.00	98.97	90.69
PM802-19-1-4	41.07	0.01	0.01	0.00	9.04	0.09	50.11	0.30	0.04	0.02	0.00	100.68	90.89
PM802-19-1-5	40.98	0.02	0.02	0.02	8.72	0.12	48.94	0.27	0.12	0.03	0.00	99.23	90.99

测点	w_B/%												En	Fs	Wo	Mg^#	Cr^#
测点	SiO₂	TiO₂	Al₂O₃	Cr₂O₃	FeO	MnO	MgO	CaO	Na₂O	K₂O	NiO	Total	En	Fs	Wo	Mg^#	Cr^#
PM802-19-1-21	55.84	0.00	2.90	1.19	5.69	0.14	32.85	0.88	0.11	0.00	0.05	99.77	89.66	8.63	1.71	91.04	21.60
PM802-19-1-22	55.23	0.02	3.93	0.83	5.98	0.14	33.06	0.46	0.11	0.01	0.09	99.86	90.05	9.05	0.90	90.68	12.43
PM802-19-1-23	56.29	0.03	3.58	0.85	5.60	0.18	32.61	1.59	0.02	0.01	0.05	100.80	88.48	8.45	3.07	91.10	13.75
PM802-19-1-24	55.82	0.01	3.17	0.89	5.78	0.13	33.26	1.16	0.12	0.03	0.09	100.48	89.16	8.61	2.23	91.00	15.87
PM802-19-1-25	55.16	0.03	3.76	0.78	6.00	0.12	34.05	0.72	0.00	0.01	0.04	102.66	89.85	8.80	1.35	90.89	12.20
PM802-19-1-26	55.85	0.01	3.90	0.94	5.44	0.15	32.57	1.71	0.01	0.00	0.11	100.68	88.47	8.22	3.31	91.32	13.86
PM802-19-1-27	55.64	0.08	3.76	0.84	5.84	0.11	32.92	1.26	0.04	0.00	0.12	100.61	88.81	8.76	2.43	90.84	13.03

测点	w_B/%												En	Fs	Wo	Mg^#	Cr^#
测点	SiO₂	TiO₂	Al₂O₃	Cr₂O₃	FeO	MnO	MgO	CaO	Na₂O	K₂O	NiO	Total	En	Fs	Wo	Mg^#	Cr^#
PM802-19-1-21	55.84	0.00	2.90	1.19	5.69	0.14	32.85	0.88	0.11	0.00	0.05	99.77	89.66	8.63	1.71	91.04	21.60
PM802-19-1-22	55.23	0.02	3.93	0.83	5.98	0.14	33.06	0.46	0.11	0.01	0.09	99.86	90.05	9.05	0.90	90.68	12.43
PM802-19-1-23	56.29	0.03	3.58	0.85	5.60	0.18	32.61	1.59	0.02	0.01	0.05	100.80	88.48	8.45	3.07	91.10	13.75
PM802-19-1-24	55.82	0.01	3.17	0.89	5.78	0.13	33.26	1.16	0.12	0.03	0.09	100.48	89.16	8.61	2.23	91.00	15.87
PM802-19-1-25	55.16	0.03	3.76	0.78	6.00	0.12	34.05	0.72	0.00	0.01	0.04	102.66	89.85	8.80	1.35	90.89	12.20
PM802-19-1-26	55.85	0.01	3.90	0.94	5.44	0.15	32.57	1.71	0.01	0.00	0.11	100.68	88.47	8.22	3.31	91.32	13.86
PM802-19-1-27	55.64	0.08	3.76	0.84	5.84	0.11	32.92	1.26	0.04	0.00	0.12	100.61	88.81	8.76	2.43	90.84	13.03

测点	w_B/%												En	Fs	Wo	Mg^#	Cr^#
测点	SiO₂	TiO₂	Al₂O₃	Cr₂O₃	FeO	MnO	MgO	CaO	Na₂O	K₂O	NiO	Total	En	Fs	Wo	Mg^#	Cr^#
PM802-19-1-6	52.90	0.00	4.01	1.24	2.22	0.10	16.68	24.02	0.11	0.00	0.04	101.35	47.55	3.52	48.93	92.96	21.60
PM802-19-1-7	52.00	0.08	3.95	1.17	2.14	0.10	16.14	24.32	0.10	0.01	0.06	100.13	46.51	3.42	50.07	93.00	12.43
PM802-19-1-8	52.44	0.03	4.16	1.14	2.01	0.07	16.37	24.72	0.22	0.01	0.04	101.26	46.57	3.18	50.25	93.47	13.75
PM802-19-1-9	52.39	0.02	4.12	1.24	2.22	0.07	16.56	24.15	0.07	0.00	0.08	100.92	47.25	3.52	49.23	92.92	15.87
PM802-19-1-10	52.74	0.05	3.94	1.30	2.08	0.02	16.74	24.29	0.06	0.00	0.03	101.26	47.49	3.28	49.22	93.40	12.20
PM802-19-1-11	53.21	0.02	3.99	1.21	2.23	0.08	16.70	24.30	0.15	0.00	0.02	101.94	47.32	3.51	49.17	92.95	13.86
PM802-19-1-12	52.86	0.09	3.82	1.08	1.95	0.03	16.42	23.87	0.29	0.07	0.02	100.61	47.52	3.14	49.34	93.67	15.99