Citation: | YANG Shengbiao, YANG Jingsui, LI Yuan, BO Rongzhong, ZHANG Jian, LI Ruibao, LIU Chengjun, LIU Fei, XIONG Fahui, CHEN Xiaojian. Late Jurassic magmatism in the Neo-Tethys Ocean: Evidence from zircon U-Pb ages and geochemistry of dolerites in the Bainang Terrane, southern Tibet[J]. Geological Bulletin of China, 2021, 40(8): 1231-1246. |
The Yarlung Zangbo suture zone(YZSZ) in southern Tibet marks the collision between the Eurasia plate and the Indian subcontinent, and the tectonic affinity of the ocean island-type(OIB-type) basaltic rocks within this suture remains controversial.The Bainang terrane in the middle segment of the YZSZ is a NE-SW-oriented tectonic slice, which is composed of radiolarian chert, siliceous mudstone, siliceous mudstone, shale, tuff, micritic limestone, basalt, dolerite and gabbro.The dolerite and gabbro are dikes or sills intruding into strata.The dolerites formed in the Late Jurassic, with a concordant zircon 206Pb/238U age of 150.3±0.8 Ma(n=39, MSWD=1.8).They are chemically characterized by LREE enrichment, variable enrichment of large ion lithophile elements(LILEs, e.g.Rb, Sr and Pb) and high field strength elements(HFSEs, Th, Nb, Ta, Zr, Hf, and Ti), indicating OIB affinity with little or no continental crust contamination.These features are similar to Late Jurassic-Early Cretaceous OIB in the YZSZ.It is suggested that these OIB rocks were derived from the intraplate environment within the Neo-Tethys and represented the remnants of seamounts.In combination with regional geological material, it is proposed that the Jurassic mantle plume in Neo-Tethys might drive the oceanic lithosphere northward subduction under the Lhasa terrane, and formed the Andean continental margin.During the Early Cretaceous, the Neo-Tethys oceanic lithosphere was decoupled from the overlying plate, and retreated southward to induce the Gangdese forearc extension to form the present ophiolites preserved in the YZSZ.
[1] | Isozaki Y, Maruyama S, Furuoka F. Accreted Oceanic Materials in Japan[J]. Tectonophysics, 1990, 181: 179-205. doi: 10.1016/0040-1951(90)90016-2 |
[2] | Wakita K, Metcalfe I. Ocean plate stratigraphy in East and Southeast Asia[J]. Journal of Asia Earth Sciences, 2005, 24: 679-702. doi: 10.1016/j.jseaes.2004.04.004 |
[3] | 付长垒, 闫臻, 王秉璋, 等. 造山带中古海山残片的识别——以拉脊山缝合带青沙山和东沟地质填图为例[J]. 地质通报, 2021, 40(1): 31-40. |
[4] | Safonova I, Maruyama S, Kojima S, et al. Recognizing OIB and MORB in accretionary complexes: A new approach based on ocean plate stratigraphy, petrology and geochemistry[J]. Gondwana Research, 2016, 33: 92-114. doi: 10.1016/j.gr.2015.06.013 |
[5] | 闫臻, 王宗起, 付长垒, 等. 混杂岩基本特征与专题地质填图[J]. 地质通报, 2018, 37(2/3): 167-191. |
[6] | 张克信, 李仰春, 王丽君, 等. 造山带混杂岩及相关术语[J]. 地质通报, 2020, 39(6): 765-782. |
[7] | Yin A, Harrison T M. Geologic Evolution of the Himalayan-Tibetan Orogen[J]. Ann. Rev. Earth Planet., 2000, 28: 211-280. doi: 10.1146/annurev.earth.28.1.211 |
[8] | 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. doi: 10.1016/j.gr.2011.10.013 |
[9] | Wang J G, Wu F Y, Garzanti E, et al. Upper Triassic turbidites of the northern Tethyan Himalaya(Langjiexue Group): The terminal of a sediment-routing system sourced in the Gondwanide Orogen[J]. Gondwana Research, 2016, 34: 84-98. doi: 10.1016/j.gr.2016.03.005 |
[10] | Liu Y M, Dai J G, Wang C S, et al. Provenance and tectonic setting of Upper Triassic turbidites in the eastern Tethyan Himalaya: Implications for early-stage evolution of the Neo-Tethys[J]. Earth-Science Reviews, 2020, 200: 103030(1-17). DOI: 10.1016/j.earscirev.2019.103030 |
[11] | Liu F, Yang J S, Dilek Y, et al. Geochronology and geochemistry of basaltic lavas in the Dongbo and Purang ophiolites of the Yarlung-Zangbo Suture zone: Plume-influenced continental margin-type oceanic lithosphere in southern Tibet[J]. Gondwana Research, 2015, 27(2): 701-718. doi: 10.1016/j.gr.2014.08.002 |
[12] | Wang H Q, Ding L, Cai F L, et al. The latest Jurassic protoliths of the Sangsang mafic schists in southern Tibet: Implications for the spatial extent of Greater India[J]. Gondwana Research, 2020, 79: 248-262. doi: 10.1016/j.gr.2019.10.008 |
[13] | Zheng H, Huang Q T, Kapsiotis A, et al. Coexistence of MORB-and OIB-like dolerite intrusions in the Purang ultramafic massif, SW Tibet: A paradigm of plume-influenced MOR-type magmatism prior to subduction initiation in the Neo-Tethyan lithospheric mantle[J]. GSA Bulletin, 2019;131(7/8): 1276-1294. |
[14] | Yang G X, Dilek Y. OIB-and P-type ophiolites along the Yarlung-Zangbo Suture Zone(YZSZ), Southern Tibet: Poly-Phase melt history and mantle sources of the Neotethyan oceanic lithosphere[J]. Episodes, 2015, 38: 250-265. doi: 10.18814/epiiugs/2015/v38i4/82420 |
[15] | 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: 396-405. doi: 10.1016/j.jseaes.2007.11.008 |
[16] | 王冉, 夏斌, 胡敬仁, 等. 仁布蛇绿混杂带洋岛型辉绿岩地球化学: 藏南特提斯洋内热点[J]. 地球化学, 2006, 35(1): 41-54. doi: 10.3321/j.issn:0379-1726.2006.01.006 |
[17] | Dai J G, Wang C S, Li Y L. Relicts of the Early Cretaceous seamounts in the central-western Yarlung Zangbo Suture Zone, southern Tibet[J]. Journal of Asian Earth Sciences, 2012, 53: 25-37. doi: 10.1016/j.jseaes.2011.12.024 |
[18] | He J, Li Y L, Wang C S, et al. Plume-proximal mid-ocean ridge origin of Zhongba mafic rocks in the western Yarlung Zangbo Suture Zone, Southern Tibet[J]. Journal of Asian Earth Sciences, 2016, 121: 34-55. doi: 10.1016/j.jseaes.2016.01.022 |
[19] | Xiong F H, Meng Y K, Yang J S, et al. Geochronology and petrogenesis of the mafic dykes from the Purang ophiolite: Implications for evolution of the western Yarlung-Tsangpo suture zone, southwestern Tibet[J]. Geoscience Frontiers, 2020, 11(1): 276-291. |
[20] | 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. |
[21] | Pan G T, Wang L Q, Li R S, et al. Tectonic evolution of the Qinghai-Tibet Plateau[J]. Journal of Asian Earth Sciences, 2012, 53: 3-14. doi: 10.1016/j.jseaes.2011.12.018 |
[22] | 吴福元, 万博, 赵亮, 等. 特提斯地球动力学[J]. 岩石学报, 2020, 36(6): 1627-1674. |
[23] | Ma X X, Xu Z Q, Zhao Z B, et al. Identification of a new source for the Triassic Langjiexue Group: Evidence from a gabbro-diorite complex in the Gangdese magmatic belt and zircon microstructures from sandstones in the Tethyan Hima-laya, southern Tibet[J]. Geosphere, 2020, 16: 407-434. doi: 10.1130/GES02154.1 |
[24] | Metcalf K, Kapp P. History of subduction erosion and accretion recorded in the Yarlung Suture Zone, southern Tibet[J]. Geological Society London Special Publications, 2019, 483: 517-554. doi: 10.1144/SP483.12 |
[25] | Ziabrev S V, Aitchison J C, Abrajevitch A V, et al. Bainang Terrane, Yarlung-Tsangpo suture, southern Tibet(Xizang, China): a record of intra-Neotethyan subduction-accretion processes preserved on the roof of the world[J]. Journal of the Geological Society, 2004, 161(3): 523-539. doi: 10.1144/0016-764903-099 |
[26] | Jackson S E, Pearson N J, Griffin W L, et al. The application of laser ablation-inductively coupled plasma-mass spectrometry to in situ U-Pb zircon geochronology[J]. Chemical Geology, 2004, 211(1/2): 47-69. |
[27] | Liu Y S, Hu Z C, Gao S, et al. In situ analysis of major and trace elements of anhydrous minerals by LA-ICP-MS without applying an internal standard[J]. Chemical Geology, 2008, 257(1/2): 34-43. |
[28] | Anderson T. Correction of common lead in U-Pb analyses that do not report 204Pb[J]. Chemical Geology, 2002, 192(1/2): 59-79. |
[29] | 李怀坤, 朱士兴, 相振群, 等. 北京延庆高于庄组凝灰岩的锆石U-Pb定年研究及其对华北北部中元古界划分新方案的进一步约束[J]. 岩石学报, 2010, 26(7): 2131-2140. |
[30] | Raczek I, Stoll B, Hofmann A W, et al. High-precision trace element data for the USGS reference materials BCR-1, BCR-2, BHVO-1, BHVO-2, AGV-1, AGV-2, DTS-1, DTS-2, GSP-1 and GSP-2 by ID-TIMS and MIC-SSMS[J]. Geostandards and Geoanalytical Research, 2001, 25(1): 77-86. doi: 10.1111/j.1751-908X.2001.tb00789.x |
[31] | 张万平, 莫宣学, 朱弟成, 等. 西藏朗县蛇绿混杂岩中变辉绿岩和变玄武岩的年代学和地球化学[J]. 成都理工大学学报(自然科学版), 2011, 38(5): 538-548. doi: 10.3969/j.issn.1671-9727.2011.05.010 |
[32] | Tatsumi Y, Eggins S. Subduction zone magmatism[M]. Oxford: Blackwell Science, 1995: 1-95. |
[33] | Wilson M. Igneous Petrogenesis[M]. London: Unwin Hyman. 1989. |
[34] | Middlemost E A K. Naming materials in the magma/igneous rock system[J]. Earth-Science Reviews, 1994, 37(3/4): 215-224. |
[35] | Winchester J A, Floyd P A. Geochemical discrimination of different magma series and their differentiation products using immobile elements[J]. Chemical Geology, 1977, 20: 325-343. doi: 10.1016/0009-2541(77)90057-2 |
[36] | Sun S S, Mcdonough W F. Chemical and isotopic systematics of oceanic basalts: Implications for mantle composition and source processes[J]. Geological Society of London, Special Publication, 1989, 42(1): 313-345. doi: 10.1144/GSL.SP.1989.042.01.19 |
[37] | Hofmann A W. Mantle geochemistry: The message from oceanic volcanism[J]. Nature, 1997, 385(6613): 218-229. doi: 10.1038/385218a0 |
[38] | Zhu D C, Mo X X, Pan G T, et al. Petrogenesis of the earliest Early Cretaceous mafic rocks from the Cona area of the eastern Tethyan Himalaya in south Tibet: Interaction between the incubating Kerguelen plume and the eastern Greater India lithosphere?[J]. Lithos, 2008, 100(1/4): 147-173. |
[39] | Belay I G, Tanaka R, Kitagawa H, et al. Origin of ocean island basalts in the West African passive margin without mantle plume involvement[J]. Nature Communications, 2019, 10: 1-12. doi: 10.1038/s41467-018-07882-8 |
[40] | Conrad C P, Wu B, Smith E I, et al. Shear-driven upwelling induced by lateral viscosity variations and asthenospheric shear: A mechanism for intraplate volcanism[J]. Physics of the Earth & Planetary Interiors, 2010, 178(3/4): 162-175. |
[41] | Foulger G R, Natland J H. Is "hotspot" volcanism a consequence of plate tectonics?[J]. Science, 2003, 300: 921-922. doi: 10.1126/science.1083376 |
[42] | Humphreys E R, Niu Y L. On the composition of ocean island basalts(OIB): The effects of lithospheric thickness variation and mantle metasomatism[J]. Lithos, 2009, 112(1/2): 118-136. |
[43] | Depaolo D J. Trace element and isotopic effects of combined wallrock assimilation and fractional crystallization[J]. Earth & Planetary Science Letters, 1981, 53(2): 189-202. |
[44] | Rudnick R L, Gao S. Composition of the Continental Crust[J]. Treatise Geochem., 2003, 3: 1-64. |
[45] | Wang B, Xie C M, Fan J J, et al. Genesis and tectonic setting of Middle Permian OIB-type mafic rocks in the Sumdo area, southern Lhasa terrane[J]. Lithos, 2019, 324/325: 429-438. |
[46] | Aldanmaz E, Pearce J A, Thirlwall M F, et al. Petrogenetic evolution of late Cenozoic, post-collision volcanism in western Anatolia, Turkey[J]. Journal of Volcanology and Geothermal Research, 2000, 102: 67-95. doi: 10.1016/S0377-0273(00)00182-7 |
[47] | Mckenzie D, O'Nions R K. Partial melt distributions from inversion of rare earth element concentrations[J]. Journal of Petrology, 1991, 32(6): 1453-1453. |
[48] | Saccani E, Allahyari K, Beccaluva L, et al. Geochemistry and petrology of the Kermanshah ophiolites(Iran): Implication for the interaction between passive rifting, oceanic accretion, and OIB-type components in the Southern Neo-Tethys Ocean[J]. Gondwana Research, 2013, 24(1): 392-411. doi: 10.1016/j.gr.2012.10.009 |
[49] | Workman R K, Hart S R. Major and trace element composition of the depleted MORB mantle(DMM)[J]. Earth & Planetary Science Letters, 2005, 231(1/2): 53-72. |
[50] | Davidson J, Turner S, Plank T. Dy/Dy*: Variations Arising from Mantle Sources and Petrogenetic Processes[J]. Journal of Petrology, 2013, 54(3): 525-537. doi: 10.1093/petrology/egs076 |
[51] | Pearce J A, Ernst R E, Peate D W, et al. LIP printing: Use of immobile element proxies to characterize Large Igneous Provinces in the geologic record[J]. Lithos, 2021: 106068. |
[52] | Duretz T, Gerya T V, May D A. Numerical modelling of spontaneous slab breakoff and subsequent topographic response[J]. Tectonophysics, 2011, 502(1): 244-256. |
[53] | 赵慧, 杨经绥, 刘飞, 等. 西藏雅鲁藏布江缝合带萨嘎碱性玄武岩地球化学和年代学研究[J]. 中国地质, 2015, 42(5): 1242-1256. doi: 10.3969/j.issn.1000-3657.2015.05.006 |
[54] | Ji W Q, Wu F Y, Chung S L, et al. Eocene Neo-Tethyan slab breakoff constrained by 45 Ma oceanic island basalt-type magmatism in southern Tibet[J]. Geology, 2016, 44: 283-286. doi: 10.1130/G37612.1 |
[55] | Liu F, Dilek Y, Yang J S, et al. A middle Triassic seamount within the western Yarlung Zangbo suture zone, Tibet: The earliest seafloor spreading record of Neotethys to the North of East Gondwana[J]. Lithos, 2021, 388/389: 106062. doi: 10.1016/j.lithos.2021.106062 |
[56] | 范建军, 李才, 牛耀龄, 等. 造山带板内洋岛-海山残片的识别及地质意义[J]. 地球科学, 2021, 46(2): 381-404. |
[57] | Metcalfe I. Multiple Tethyan Ocean basins and orogenic belts in Asia[J]. Gondwana Research, 2021, https://doi.org/10.1016/j.gr.2021.01.012. doi: 10.1016/j.gr.2021.01.012 |
[58] | Zhu D C, Zhao Z D, Niu Y L, et al. Lhasa terrane in southern Tibet came from Australia[J]. Geology, 2011, 39(8): 727-730. doi: 10.1130/G31895.1 |
[59] | Zhu D C, Zhao Z D, Niu Y L, et al. The Lhasa Terrane: record of a microcontinent and its histories of drift and growth[J]. Earth and Planetary Science Letters, 2011, 301: 241-255. doi: 10.1016/j.epsl.2010.11.005 |
[60] | Chatterjee S, Goswami A, Scotese C R. The longest voyage: tectonic, magmatic, and paleoclimatic evolution of the Indian plate during its northward flight from Gondwana to Asia[J]. Gondwana Research, 2013, 23: 238-267. doi: 10.1016/j.gr.2012.07.001 |
[61] | Zhang K J, Zhang, Y X, Tang X C, et al. Late Mesozoic tectonic evolution and growth of the Tibetan plateau prior to the Indo-Asian collision[J]. Earth-Science Reviews, 2012, 114: 236-249. doi: 10.1016/j.earscirev.2012.06.001 |
[62] | Xiong Q, Griffin W L, Zheng J P, et al. Southward trench migration at~130-120 Ma caused accretion of the NeoTethyan forearc lithosphere in Tibetan ophiolites[J]. Earth and Planetary Science Letters, 2016, 438: 57-65. doi: 10.1016/j.epsl.2016.01.014 |
[63] | Wang C S, Li X H, Liu Z F, et al. Revision of the Cretaceous-Paleogene stratigraphic framework, facies architecture and provenance of the Xigaze forearc basin along the Yarlung Zangbo suture zone[J]. Gondwana Research, 2012, 22: 415-433. doi: 10.1016/j.gr.2011.09.014 |
[64] | 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. |
[65] | Wang J G, Hu X M, Garzanti E, et al. The birth of the Xigaze forearc basin in southern Tibet[J]. Earth and Planetary Science Letters, 2017, 465: 38-47. doi: 10.1016/j.epsl.2017.02.036 |
[66] | Maffione M, van Hinsbergen D J J, Koornneef L M T, et al. Forearc hyperextension dismembered the south Tibetan ophiolites[J]. Geology, 2015, 43: 475-478. doi: 10.1130/G36472.1 |
[67] | Butler J P, Beaumont C. Subduction zone decoupling/retreat modeling explains south Tibet(Xigaze) and other supra-subduction zone ophiolites and their UHP mineral phases[J]. Earth and Planetary Science Letters, 2017, 463: 101-117. doi: 10.1016/j.epsl.2017.01.025 |
Simplified geological map of the YZSZ(a)and geological map of its central part(b)
Field photographs(a~i)of the Bainang Terrane and microphotographs(j, k)of dolerite in the Naru area, Gyangze
Cathodoluminescence images of the zircons of the dolerite from the Bainang Terrane in the Naru area, Gyangze
U-Pb concordia(a) and 206Pb/238U age(b)diagrams of the zircons from dolerite(Y19R-27-26) of the Bainang Terrane in the Naru area, Gyangze
SiO2-(Na2O+K2O)(a)and Nb/Y-Zr/Ti(b)classification diagrams of the dolerite from the Bainang Terrane in the Naru area, Gyangze
Chondrite-normalized REE patterns(a)and primitive-mantle normalized spider diagrams(b)of the dolerite from the Bainang Terrane in the Naru area, Gyangze
(La/Nb)PM vs.(Th/Nb)PM(a)and Ti/Yb vs.Nb/Th (b)diagrams of the dolerite from the Bainang Terrane in Naru area, Gyangze
Dy/Yb vs.Dy/Dy*(a)and La/Sm vs.Sm/Yb (b) diagrams of the dolerite from the Bainang Terrane in Naru area, Gyangze
Nb/Yb vs.Th/Yb(a)and TiO2/Yb vs.Th/Nb(b) discrimination diagrams of the dolerite from the Bainang Terrane in the Naru area, Gyangze
Simplified geodynamic model for the evolution of the the Neo-Tethys ocean in Southern Tibet