西昆仑塔什库尔干苦子干碱性杂岩体的成因及其构造意义
Petrogenesis and Tectonic Implications of the Cenozoic Alkaline Complex in Kuzigan, Taxkorgan, West Kunlun
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摘要: 苦子干碱性杂岩体是塔什库尔干新生代碱性岩带的主要组成之一，主要由霓辉正长岩、石英霓辉正长岩和碱性花岗岩组成。霓辉正长岩、石英霓辉正长岩和碱性花岗岩的SiO2含量差别较大，分别为50.26%~54.11%、59.74%~60.43%、69.59%~72.13%；霓辉正长岩与石英霓辉正长岩的里特曼指数相近，分别为7.83~10.97、8.51~9.05，明显不同于碱性花岗岩（2.49~3.71）。这3种碱性岩石都表现出富集轻稀土，以及K、Rb、Sr、Ba等大离子亲石元素（LILE），亏损Nb、Ta、Ti等高场强元素（HFSE）的特征。其中异常高的Sr、Ba和∑REE含量暗示可能还有富集地幔物质的加入。利用原位锆石LA-ICP-MS同位素测试方法，获得石英霓辉正长岩和碱性花岗岩的锆石U-Pb年龄分别为10.9±0.1 Ma和 11.9±0.4 Ma，代表了岩石的结晶年龄；石英霓辉正长岩锆石εHf（t）值为-9.78~3.24，碱性花岗岩中锆石εHf（t）值为-13.54~5.78，均显示岩浆源区具有壳幔混合的特点。依据这些资料，并结合区域地质研究的综合分析，笔者初步提出西昆仑塔什库尔干苦子干碱性杂岩体的形成是由于青藏高原在~25 Ma期间主体拆沉作用发生后，造成软流圈物质向北逃逸，并受到北面塔里木克拉通岩石圈山根阻挡而上涌，进而发生壳幔混合作用的产物。因此，该杂岩体是青藏高原大规模拆沉后浆活动的远程效应，且标志着研究区在~11 Ma期间已处于伸展构造背景。Abstract: Kuzigan alkaline complex is one of the major parts of the Taxkorgan alkaline complexterrane. It is mainly composed of aegirine-augite syenite, quartz aegirine-augite syenite, and alkali granite. There is great difference among the three rocks in the content of SiO2, 50.26%-54.11%, 59.74%-60.43% and 69.59%-72.13% for aegirine-augite syenite, quartz aegirine-augite syenite and alkali granite, respectively. Aegirine-augite syenite and quartz aegirine-augite syenite has similar Rittman index, namely 7.83-10.97 and 8.51-9.05, distinctly differing from 2.49-3.71 of alkali granite. These three rocks are strongly enriched in light rare earth elements (LREE) as well as some large ion lithophile element (LILE), such as Rb, Ba, Sr, and depleted in High Field Strength Element (HFSE) such as Nb, Ta and Ti. Abnormal high Sr, Ba and ∑ REE content may imply the mixing of enriched mantle materials. LA-ICP-MS in-situ zircon U-Pb dating obtain the ages of 10.9±0.1 Ma and 11.9±0.4Ma for the quartz aegirine-augite syenite and alkali granite respectively, representing the crystallization ages of the two rocks. The εHf(t) values of the quartz aegirine-augite syenite and alkali granite are of -9.78-3.24 and -13.54-5.78, showing the crust-mantle mixing in magma source area. According to the comprehensive analysis and combined with regional geological data, we preliminarily hypothesized that the Kuzigan alkaline complex is a product of the crust-mantle mixing, which is caused by the asthenosphere flowing northward due to the delamination of the Tibetan plateau at ~25Ma, and the asthenosphere upwelling as a result of the obstruction of the root of the Tarim craton lithosphere. Therefore, the formation of the complex is a fernwirkung of the magmation after Tibetan plateau large-scale delamination, and it signifies that during ~11 Ma the study area was in extensional tectonic setting.
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-
鲍佩声, 肖序常, 苏梨, 等.西藏高原西北缘钾质火山岩地球化学特征及其地质涵义[J].地质学报, 2006, 80(10):1578-1587.
Bao P S, Xiao X C, Su L, et al.Geochemical Characteristics of the Potassic Volcanics in the Northwestern Tibet Plateau and Its Implications[J].Acta Geologica Sinica, 2006, 80(10):1578-1587 (in Chinese).
陈斌, 刘超群, 田伟.太行山中生代岩浆作用过程中的壳幔岩浆混合作用:岩石学和地球化学证据[J].地学前缘, 2006, 13(2):140-147.
Chen B, Liu C Q, Tian W.Magma-mixing between mantle and crustal-derived melts in the process of Mesozoic magmatism, Taihangshan: constraints from petrology and geochemistry[J].Earth Science Frontiers, 2006, 13(2):140-147 (in Chinese).
邓万明.青藏及其邻区新生代火山岩活动及构造演化[J].地震地质, 2003, 25 (增刊): 51-61.
Deng W M. Cenozoic volcanism and tectonic evolution in the Tibetan plateau and its adjacent areas[J].Seisnology and Geology, 2003, 25(Sup.):51-61 (in Chinese). 邓万明.青藏北部新生代钾质火山岩微量元素和Sr、Nb同位素地球化学研究[J].岩石学报, 1993, 9 (4):379-386.
Deng W M.Study on trace element and Sr、Nb isotopic geochemistry of cenozoic potassic volcanic rocks in north Tibet[J].Acta Petrologica Sinica, 1993, 9 (4):379-386 (in Chinese).
邓万明, 孙宏娟. 青藏高原新生代火山岩活动与高原隆升关系[J].地质评论, 1999, 45(增刊):952-958.
Deng W M, Sun H J. Relationship between Cenozoic volcanism in the Qinghai-Tibetan Plateau and its uplifting[J].Geological Review, 1999, 45(Sup.): 952-958 (in Chinese).
丁林, 张进江, 周勇, 等.青藏高原岩石圈演化的记录:藏北超钾质及纳质火山岩的岩石学与地球化学特征[J].岩石学报, 1999, 15(3):408-421.
Ding L, Zhang J J, Zhou Y, et al. Tectonic implication on the lithosphere evolution of the Tibet Plateau: Petrology and geochemistry of sodic and ultrapotassic volcanism in Northern Tibet[J].Acta Petrologica Sinica, 1999, 15(3):408-421 (in Chinese).
高锐, 黄东定, 卢德源, 等.横过西昆仑造山带与塔里木盆地结合带的深地震反射剖面[J].科学通报, 2000, 45(17):1874-1879.
Gao R, Huang D D, Lu D Y, et al. Deep seismic reflection profile across the conjunct zone between the Tarim basin and the West Kunlun Mountains[J].Chinese Science Bulletin, 2000, 45(17):1874-1879(in Chinese).
高锐, 肖序常, 高弘, 等.西昆仑-塔里木-天山岩石圈深地震探测综述[J].地质通报, 2002. 21(1): 11-18.
Gao R, Xiao X C, Gao H, et al. Summary of deep seismic probing of the lithospheric structure across the West Kunlun-Tarim-Tianshan[J].Geological Bulletin of China, 2002, 21(1):11-18 (in Chinese).
贺日政, 赵大鹏, 高锐, 等.西昆仑造山带下岩石圈地幔速度结构[J].地球物理学报, 2006, 49(3):778-787.
He R Z, Zhao D P, Gao R, et al. Teleseismic P-wave tomography of lithospheric mantle beneath west Kunlun orogenic belts[J].Chinese Journal of Geophysics, 2006, 49(3):778-787 (in Chinese).
姜耀辉, 杨万志. 青藏高原西部喜马拉雅期花岗岩类特征及岩石系列[J].岩石矿物学杂志, 2000, 19(4): 289-296. Jiang Y H, Yang W Z.Geochemical Characteristics and Rock Series of Himalayan Granitoids in Western Qinghai-Xizang Plateau[J].Acta Petrologica et Mineralogic, 2000, 19(4): 289-296 (in Chinese).
堪宏伟, 罗照华, 莫宣学, 等.东昆仑造山带三叠纪岩浆混合成因花岗岩的岩浆底侵作用机制[J].中国地质, 2005, 33(3):386-395.
Kan H W, Luo Z H, Mo X X, et al. Underplating mechanism of Triassic granite of magma mixing origin in the East Kunlun orogenic belt[J].Geology in China, 2005, 32(3):386-395 (in Chinese).
柯珊, 罗照华, 莫宣学.塔什库尔干新生代碱性杂岩造岩矿物化学成分及成因意义[J].岩石矿物学杂志, 2006b, 25 (2):148-156.
Ke S, Luo Z H, Mo X X. Mineralogy of Taxkorgan Cenozoic alkaline complex in Xinjiang and its implication to pluton genesis[J].Acta Petrologica et Mineralogica, 2006b, 25(2):148-156.
柯珊, 罗照华, 莫宣学, 等.帕米尔构造结塔什库尔干碱性杂岩同位素年代学研究[J].岩石学报, 2008, 24(2):315-324.
Ke S, Luo Z H, Mo X X, et al.The geochronology of Taxkorgan alkaline complex, Pamir syntax[J].Acta Petrology sinica, 2008, 24(2): 315-324 (in Chinese).
柯珊, 莫宣学, 罗照华, 等.塔什库尔干碱性杂岩的地球化学特征及其岩石成因[J]. 岩石学报, 2006a, 22(4):905-915.
Ke S, Mo X X, Luo Z H, et al.Petrogenesis and geochemistry of Cenozoic Taxkorgan alkalic complex and its geological significance[J].Acta Petrologica Sinica, 2006a, 22(4):905-915 (in Chinese).
赖绍聪.青藏高原新生代埃达克岩石的厘定及其意义[J].地学前缘, 2003, 10(4), 407-415.
Lai S C. Identification of the Cenozoic adakitic rock association from Tibetan plateau and its tectonic significance[J].Earth Science Frontiers, 2003, 10(4):407-415 (in Chinese).
赖绍聪, 秦江峰, 李永飞, 等.青藏高原新生代火车头山碱性及钙碱性两套火山岩的地球化学特征及其物源讨论[J].岩石学报, 2007, 23(4):709-718.
Lai S C, Qin J F, Li Y F, et al. Geochemistry and petrogenesis of the alkaline and calc-alkaline series Cenozoic volcanic rocks from Huochetou mountain-Tibetan plateau[J].Acta Petrologica Sinica, 2007, 23(4):709-718 (in Chinese).
赖绍聪.青藏高原北部新生代火山岩的成因机制[J].岩石学报, 1999, 15(1): 98-104.
Lai S C. Petrogenesis of the Cenozoic volcanic rocks from the northern part of the Qinghai-Tibet Plateau[J].Acta Petrologica Sinica, 1999, 15(1): 98-104 (in Chinese).
李海兵, Valli F, 刘敦一, 等.喀喇昆仑断裂的形成时代锆石SHRIMP U-Pb 年龄的制约[J].科学通报, 2007. 52(5): 438-447.
Li H B, Valli F, Liu D Y, et al.Initial movement of the Karakorum Fault in western Tibet: Constraints from SHRIMP U-Pb dating of zircons[J].Chinese Science Bulletin, 2007, 52(5): 438-447 (in Chinese) 李海兵, Valli F, 许志琴, 等.喀喇昆仑断裂带的变形特征及构造演化[J].中国地质, 2006, 33(2):239-255.
Li H B, Valli F, Xu Z Q, et al. Deformation and tectonic evolution of the Karakorum fault, western Tibet[J].Geology in China, 2006, 33(2):239-255, (in Chinese).
李海兵, Valli F Arnaud N, 等.喀喇昆仑断裂带走滑过程中伴随的快速隆升作用:热年代学证据[J].岩石学报, 2008, 24 (7):1552-1566.
李荣社, 计文化, 杨永成.昆仑山及其邻区地质[M].北京:地质出版社, 2008.
Li R S, Ji W H, Yang Y C, et al. Geology of Kunlun Mountain and Adjacent Regions[M].Geological Publishing House, Beijing, 2008 (in Chinese).
林清茶, 夏斌, 张玉泉.西昆仑-喀喇昆仑地区钾质碱性岩Ar-Ar 年龄-以羊湖、昝坎和苦子干岩体为例[J].矿物学报, 2006, 26(2):66-70.
Lin Q C, Xia B, Zhang Y Q. Ar-Ar dating of potassic alkali-rocks in the western Kunlun-Klakorum mountains -Example for the rocks of Yanghu, Zan kan and Kuzigan[J].Mineral Petrol, 2006, 26 (2):66-70 (in Chinese).
刘栋梁, 李海兵, 潘家伟, 等. 帕米尔东北缘-西昆仑的构造地貌及其构造意义[J]. 岩石学报, 2011, 27 (11):3499-3512.
Liu D L, Li H B, Pan J W, et al. Morphotectonic study from the northeastern margin of the Pamir to the West Kunlun rang and its tectonic implications[J]. Acta Petrologica Sinaca, 2011, 27(11):3499-3512 (in Chinese).
罗照华, 莫宣学, 侯增谦, 等. 青藏高原新生代形成演化的整合模型-来自火成岩的约束[J].地学前缘, 2006, 13(4):196-211.
Luo Z H, Mo X X, Hou Z Q, et al.An integrated model for the Cenozoic evolution of the Tibetan plateau: constraints from igneous rocks[J].Earth Science Frontiers, 2006, 13(4):196-211 (in Chinese).
罗照华, 莫宣学, 柯珊. 塔什库尔干碱性杂岩体形成的时代及其地质意义[J].新疆地质, 2003, 21(01): 46-50.
Luo Z H, Mo X X, Ke S. Ages of Taxkorgan alkaline intrusive complex and their geological implications[J].Xinjiang Geology, 2003, 21(01):46-50 (in Chinese).
潘裕生.喀喇昆仑山-昆仑山地区地质演化[M].北京:科学出版社, 2000: 209-258.
Pan Y S, Geological Evolution of the Karakorum-Kunlun Mountains[M]. Sciences Press, Beijing, 2000: 209-258 (in Chinese).
潘裕生, 王毅, Matte P H, 等. 青藏高原叶城-狮泉河路线地质特征及区域构造演化[J].地质学报, 1994, 68: 295-307.
Pan Y S, WANG Y, MATTE P H, et al. Tectonic evolution along the geotraverse from Yecheng to Shiquanhe[J]. Acta Geologica Sinica, 1994, 68: 295-307 (in Chinese).
潘裕生.昆仑山区构造区划初探[J].自然资源学报, 1989, (4): 196-203.
Pan Y S. A preliminary study on the regionalization of the structures in the Kunlun Mountains region[J].Journal Natural Resources, 1989, (4): 196-203 (in Chinese).
钱俊峰, 肖安成, 杨树峰, 等.南天山造山带与西昆仑(帕米尔)造山带深层岩石圈对接[J].科技通报, 2009, 25(2):153-166.
Qian J F, Xiao A C, Yang S F, et al. Deep Lithospheric Jointing Relationship between South Tienshan Orogen and West Kunlun(Pamir) Orpgen[J]. Bulleting of Science and Tecgnology, 2009, 25(2): 153-166 (in Chinese).
王联魁, 夏斌, 张玉泉, 等. 研究"钾质和钠质两个地幔富碱岩浆体系"的刍议[J]. 高校地质学报, 2003, 9(4):545-555.
Wang L K, Xia B, Zhang Y Q, et al.A Humble Opinion on the "Potassic and Sodic Two Mantle Alkali-Rich Magma Systems"[J]. Geological Journal of China Universities, 2003, 9(4):545-555 (in Chinese).
王涛, 刘燊, 胡瑞忠, 等.苏鲁造山带碱性岩的成因研究—主微量元素地球化学证据[J]. 矿物学报, 2010, 30(2):194-205.
Wang T, Liu S, Hu R Z, et al.Petrogenesis of Alkaline Rocks in the Sulu Orogen-Evidence from Elemental Geochemistry[J].Acta Mineralogica Sinica, 2010, 30(2):194-205 (in Chinese).
吴福元, 黄宝春, 叶凯, 等.青藏高原造山带的垮塌与高原隆升[J].岩石学报. 2008, 24 (1):1-30.
Wu F Y, Huang B C, Ye K, et al. Collapsed Himalayan-Tibetan orogen and the rising Tibetan Plateau[J].Acta Petrologica Sinica, 2008, 24(1):1-30. 肖序常, 王军. 西昆仑-喀喇昆仑及其邻区岩石圈结构、演化中几个问题的探讨[J]. 地质评论, 2004, 50(3):285-294.
Xiao X C, Wang J. Discussion on the Lithospheric Structure and Evolution of the West Kunlun Mountains-Karakorum Mountains and Their Adjacent Areas[J].Geological Review, 2004, 50(3):285-294 (in Chinese).
杨进辉, 吴福元, 谢烈文, 等.辽东矿洞沟正长岩成因及其构造意义:锆石原位微区U-Pb年龄和Hf同位素制约[J]. 岩石学报, 2007, 23(2):263-276.
Yang J.H, Wu F.Y, Xie L.W, et al. Petrogenesis and tectonic implications of Kuangdonggou sysnites in the Liaodong Peninsula, east North China Craton: Constraints from in-situ zircon U-Pb ages and Hf istopes[J]. Acta Petrologica Sinica, 2007, 23(2):263-276 (in Chinese).
张玉泉, 谢应雯. 哀牢山-金沙江富碱侵入岩年代学和Nd, Sr同位素特征[J].中国科学, (D辑), 1997, 27, (4):289-293.
Zhag Y Q, Xie Y W. Geochronology of Ailaoshan-Jinshajiang alkalic-rich intrusive rocks and their Sr and Nd isotopic characteristics[J].Sciense in China (Ser D), 1997, 27 (4): 289-293 (in Chinese).
张玉泉, 谢应雯. 青藏高原及邻区富碱侵入岩-以苦干子和太和二岩体为例[J].中国科学, 1994, 24(10):1102-1108.
Zhang Y Q, Xie Y W. Alkali-rich intrusive rocks in the Qinghai-Xizang Plateau and its vicinities as exemplified by Kuzigan and Taihe plutons[J].Science in Chnia, (Ser B), 1994, 24(10):1102-1108 (in Chinese).
Bievre D.P, Taylor P D. Table of the isotopic composition of the elements. International Journal of Mass Spectrometry and Ion Processes 1993, 123 (2):149-166.
Bonin B, AZZOUNI-SEKKAL A, BUSSY F, et al.Alkali-calcic and alkaline post-orogenic(PO)granite magmatism: petrologic constaints and geodynamic setiing[J]. Lithos, 1998, 45:45-70.
Bonnin B. From orogenic to anorogenic settings: evolution of granitoid suites after a major orogenesis[J]. Geo. J. 1990, 25:261-270.
Foder R V, Vetter S K.Rift zone magmatism: petrology of basaltic rocks transitional from CFB to MORB, Southestern Brazil margin[J].Contrib Mineral, 1984, 88:307-321.
Gao S, Luo T C, Zhang B R et al.Chemical composition of the continental crust as revealed by studies in East China[J].Geochimica et Cosmochimica Acta, 1998, 62(11):1959-1975.
Hou Z Q, Gao Y F, Qu X M, et al. Origin of adakitic intrusives generated during mid-Miocene east-west extension in southern Tibet[J].Earth Planet Science Letters, 2004, 220:139-155.
Ionov D A, Hofmann A W.Nb, Ta-rich mantle amphiboles and micas: Implications for subduction-related metasomatic trace element fractions[J].Earth and Planetary Science Letter, 1995, 131∶341-356.
Kamber S, Collerson D. Zr/Nb Systematics of Ocean Island Basalts Reassessed-the Case for Binary Mixing[J]. Journal of Peteology, 2000, 41(7):1007-1021. Kieffer B, Amdt N, Lapierre H, et al. Fllod and shield basalts from Ethiopia: magmas from the African superswell[J].Petrol, 2004, 45(4):793-834.
Klemperer S L. Crustal flow in Tibet: geophysical evidence for the physical state of Tibetan lithosphere, and inferred patterns of active flow[J].Geological Society, London, Special Publication, 2006, 268:39-70.
Lacassin R, Valli F, Amaud A, et al.Large-scale geometry, offset and kinematic evolution of the Karakorum fault, Tibet[J].Earth and Planetary Science Letters, 2004, 219:255-269.
Li H B, Valli F, Amaud N, et al. Rapid uplifting in the process of strike-slip along the Karokorum faut zone in western Tibet: Evidence from40Ar/39Ar thermochronology[J].Acta Petrologica Sinica, 2008, 24 (7): 1552-1566 (in Chinese).
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.Chemical Geology, 2008, 257(1-2): 34-43.
Luo Z H, Xiao X C, Cao Y Q, et al.The Cenozoic mantle magmatism and motion of lithosphere on the north margin of the Tibetan Plateau[J].Science in China, 2001, (Series D) 44 (Sup.): 10-17. Maheo G, Guillot S, Blichert-toft J, et al. A slab break off model for The Neogene thermal evolution of South Karakorum and South Tibet[J].Earth and Planetary Science Letters, 2002, 195: 45-58.
Matte P H, Tapponnier P, Amaud N, et al. Tectonics of Western Tibet, between the Tarim and the Indus[J]. Earth and Planetary Science Letters, 1996, 142:311-330.
Rudnick R L, Fountain D M.Nature and composition of the continental crust: A lower crustal perspective[J]. Review Geophysics, 1995, 33:267-309.
Saunders A D, Storey M, Kent R.W, et al. Consequences of plume-lithosphere interaction. Pub, London, 1992, 68:41-60.
Sobel E R, Schoenbohm L M, Chen J, et al. Late Miocene-Pliocene deceleration of dextral slip between Pamir and Tarim: Implications for Pamir orogenesis[J].Earth and Planetary Science Letters, 2011, 304:369-378.
Stem R, Kilian R.Role of the subducted slab, mantle wedge and continental crust in the reneIation of adakites from the Andean Austral volcanic zone. Contrib. Mineral. Petrol, 1996, 123:263-281.
Sylvester P J. Post-collisional strongly peraluminous granites[J]. Lithos, 1998, 45:29-44.
Tapponnier P, Xu Z Q, Roger F, et al. Oblique Stepwise Rise and Growth of the Tibet Plateau[J].Science, 2001, 294 (5547):1671-1677.
Taylor S R, Mclennan S M. The geochemical evolution of the continental crust [J].Review in Geophysics, 1995, 33:241-265.
Wang G C, Cao K, Zhang K X, et al.Spatio-temporal framework of tectonic uplift stages of the Tibetan Plateau in Cenozoic[J].Sci China Earth Sci, 2011, 54: 29-44.
Wilson M.Igneous petrogenesis: a gobal tectonic approach[M].London: Unwin Hyman, 1989.
Wittlinger G, Vergne J, Tapponnier P, et al. Teleseismic imaging of subducting lithosphere and Moho offsets beneath western Tibet[J].Earth Planet Science Letters, 2004, 221∶117-130.
Yang J H, Chung S L, Wilde S A, et al. Petrogenesis of post-orogenic sysnite in the Sulu Orogenic evidence[J].Chem. Geol, 2005, 214:99-125.
Yang W Q, Liu L, Cao Y T, et al.Geochronological evidence of Indosinian (high-pressue)metamorphic event and its tectonic significance in Taxkorgan area of the Western Kunlun Mountains, NW China[J].Sci China Earth Sci, 2010, 53:1445-1459.
Yuan H L, Gao S, Dai M N, et al. Simultaneous determination of U-Pb age, Hf isotopes and trace element compositions of zircon by excimer laser-ablation quadrupole and multiple-collector ICP-MS[J].Chemical Geology, 2008, 247(1-2):100-118.
Liu Y S, Hu Z C, Zong K Q, et al. Reappraisement and refinement of zircon U-Pb isotope and trace element analyses by LA-ICP-MS[J].Chinese Science Bulletin, 2010, 55(15): 1535-1546. Wu Y B, Zheng Y F.Genesis of zircon and its constraints on interpretation of U-Pb age[J].Chinese Science Bulletin, 2004, 49(15):1554-1569.
Xiao W J, WINDLEEY B F, HAO J, et al. Arc-ophiolite obduction in the western Kunlun range (China): Implications for the Palaeozoic evolution of central Asia [J].J Geol Soc London, 2002, 159: 517-528.
Xiao X C, Liu X, et al. Collision tectonics between the Tarim block (Basin) and the Northwestern Tibet plateau: New observations from a multidisciplinary geoscientific investgation in the Western Kunlun Mountains[J].Acta Geologica Sinica, 2001, 75(2):126-132.
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