Citation: | SHE Jianzhong, JIA Jian, DI Xiaochen, PENG Ge, DUAN Xujie, XIAO Meng, DONG Guosheng, LIU Kaixuan. Zircon U-Pb age, Hf isotope, petrogeochemical characteristics and tectonic significance of the I type granites in the middle part of Xiemisitai Mountain in West Junggar[J]. Geological Bulletin of China, 2019, 38(11): 1790-1800. |
Jigentai is in the middle part of western Junggar. The authors found a set of Late Devonian granites surrounded by middle stage Variscan granite. The LA-ICP-MS zircon U-Pb age is 364.0±6.0Ma, suggesting Late Devonian granite which was discovered for the first time in this area. The lithology is composed of hornblende quartz monzonite and hornblende diorite. The rock has lower TiO2 (0.49%~0.54%), relatively higher Al2O3 (16.09%~16.74%), and higher total alkali content (7.07%~8.52%), and has rich sodium. The distribution curve of rare earth elements shows a steep and moderate right-inclined curve, with relative enrichment of large ion lithophile elements Ba, K, Sr and high field strength elements Zr, Hf, Sm but relative depletion of high field strength elements Nb, Ta, P, Ti. The rock has a positive εHf(t) (6.09~-12.91). The geochemical and mineralogical characteristics of the rock indicate that the rock mass is an island-arc type and I-type granite, and the source rock might have been partially melted from the material of the shear zone between the subduction plate and the lithosphere at the bottom of the island arc, and was in the process of ascending. It was contaminated by the upper crust. The discovery of the Late Devonian Island Arc Type I-granite in this area reveals the successive connection of the ocean basin stage, the subduction and accretion stage and the post-collision stage.
[1] | 韩宝福, 季建清, 宋彪, 等.新疆准噶尔晚古生代陆壳垂向生长(Ⅰ)——后碰撞深成岩浆活动的时限[J].岩石学报, 2006, (5):1077-1086. |
[2] | 童英, 王涛, 洪大卫, 等.北疆及邻区石炭-二叠纪花岗岩时空分布特征及其构造意义[J].岩石矿物学杂志, 2010, 29(6):619-641 doi: 10.3969/j.issn.1000-6524.2010.06.003 |
[3] | 高睿, 肖龙, 王国灿, 等.西准噶尔晚古生代岩浆活动和构造背景[J].岩石学报, 2013, 29(10):3413-3434. |
[4] | Chen J F, Han B F, Ji J Q, et al. Zircon U-Pb ages and tectonic implications of Paleozoic plutons in northern West Junggar, North Xinjiang, China[J]. Lithos, 2010, 115(14):137-152. |
[5] | 陈家富, 韩宝福, 张磊.西准噶尔北部晚古生代两期侵入岩的地球化学、Sr-Nd同位素特征及其地质意义[J].岩石学报, 2010, 26(8):2317-2335. |
[6] | Chen B, Jahn B M. Genesis of post-collisional granitoids and basement nature of the Junggar Terrane, NW China:Nd-Sr isotopeand trace element evidence[J]. Journal of Asian Earth Sciences, 2004, 23(5):691-703. doi: 10.1016/S1367-9120(03)00118-4 |
[7] | 苏玉平, 唐红峰, 侯广顺, 等.新疆西准噶尔达拉布特构造带铝质A型花岗岩的地球化学研究[J].地球化学, 2006, (1):55-67. |
[8] | Geng H Y, Sun M, Yuan C, et al. Geochemical, Sr-Nd and zircon U-Pb-Hf isotopic studies of Late Carboniferous magmatism in the West Junggar, Xinjiang:Implications for ridge subduction?[J]. Chemical Geology, 2009, 266(34):364-389. |
[9] | Windley B F, Alexeiev D, Xiao W J, et al. Tectonic models for accretion of the Central Asian Orogenic Belt[J]. Journal of the Geological Society of London, 2007, 164:31-47. doi: 10.1144/0016-76492006-022 |
[10] | 李锦轶.新疆东部新元古代晚期和古生代构造格局及其演变[J].地质论评, 2004, 50(3):304-321. doi: 10.3321/j.issn:0371-5736.2004.03.015 |
[11] | 张元元, 郭召杰.准噶尔北部蛇绿岩形成时限新证据及其东、西准噶尔蛇绿岩的对比研究[J].岩石学报, 2010, 26(2):422-430. |
[12] | 段丰浩, 李永军, 陈荣光, 等.新疆西准噶尔库尔尕克希岩体年代学、地球化学特征及岩石成因[J].岩石矿物学杂志, 2017, 36(3):295-311. doi: 10.3969/j.issn.1000-6524.2017.03.002 |
[13] | 徐芹芹, 季建清, 龚俊峰, 等.新疆西准噶尔晚古生代以来构造样式与变形序列研究[J].岩石学报, 2009, 25(3):636-644. |
[14] | 陈宣华, 聂兰仕, 丁伟翠, 等.西准噶尔走滑断裂系元素分布特征及其成矿意义[J].岩石学报, 2015, 31(2):371-387. |
[15] | 魏永明, 蔺启忠, 肖磉, 等.新疆西准噶尔地区不同尺度地质构造的遥感标识特征及找矿意义[J].大地构造与成矿学, 2015, 39(1):76-92. doi: 10.3969/j.issn.1001-1552.2015.01.008 |
[16] | 何国琦, 刘建波, 张越迁, 等.准噶尔盆地西缘克拉玛依早古生代蛇绿混杂岩带的厘定[J].岩石学报, 2007, 23(7):1573-1576. doi: 10.3969/j.issn.1000-0569.2007.07.002 |
[17] | Xiao W J, Han C M, Yuan C, et al. Middle Cambrian to Permian subduction-related accretionary orogenesis of Northern Xinjiang, NW China:Implications for the tectonic evolution of Central Asia[J]. Journal of Asian Earth Sciences, 2008, 32(24):102-117. doi: 10.1016/j.jseaes.2007.10.008 |
[18] | 易善鑫, 李永军, 焦光磊, 等.西准噶尔博什库尔-成吉斯火山弧早石炭世火山岩的确立及构造意义[J].新疆地质, 2014, 32(1):14-18. doi: 10.3969/j.issn.1000-8845.2014.01.003 |
[19] | 侯可军, 李延河, 邹天人, 等. LA-MC-ICP-MS锆石Hf同位素的分析方法及地质应用[J].岩石学报, 2007, 23(10):2595-2604. doi: 10.3969/j.issn.1000-0569.2007.10.025 |
[20] | Sun S S, Mc Donough W F. Chemical and isotopic systematics of oceanic basalts: Implications for mantle composition and processes[C]//Saunders A D, Norry M J. Magmatism in the Ocean Basins. Geological Society Special Publication, London, 1989: 313-345. |
[21] | 吴元保, 郑永飞.锆石成因矿物学研究及其对U-Pb年龄解释的制约[J].科学通报, 2004, (16):1589-1604. doi: 10.3321/j.issn:0023-074X.2004.16.002 |
[22] | 杨进辉, 吴福元, 邵济安, 等.冀北张-宣地区后城组、张家口组火山岩锆石U-Pb年龄和Hf同位素[J].地球科学, 2006, (1):71-80. doi: 10.3321/j.issn:1000-2383.2006.01.010 |
[23] | 吴福元, 李献华, 郑永飞, 等. Lu-Hf同位素体系及其岩石学应用[J].岩石学报, 2007, 23(2):185-220. |
[24] | Blichert T J, Albarède F. The Lu-Hf geochemistry of chondrites and the evolution of the mantle-crust system[J]. Earth and Planetary Science Letters, 1997, 148:243-258. doi: 10.1016/S0012-821X(97)00040-X |
[25] | Griffin W L, Pearson N J, Belousova E, et al. The Hf isotope composition of cratonic mantle:LAM-MC-ICPMS analysis of zircon megacrysts in kimberlites[J]. Geochimica et Cosmochimica Acta, 2000, 4:133-147. doi: 10.1016/s0016-7037(99)00343-9 |
[26] | Soderlund U, Patchett P J, Vervoort J D, et al. The 176Lu decay constant determined by Lu-Hf and U-Pb isotopesystematics of Precambrian mafic intrusions[J]. Earth and Planetary Science Letters, 2004, 219:311-324. doi: 10.1016/S0012-821X(04)00012-3 |
[27] | Chappell B W, White A J R. I- and S-Type Granites in the Lachlan Fold Belt[J]. Transactions of the Royal Society of Edinburgh:Earth Sciences, 1992, (83):1-26. doi: 10.1017/s0263593300007720 |
[28] | Miller C F. Are strongly Peraluminous Magmas Derived from Pelitic Sedimentary Sources?[J].The Journalof Geology, 1985, 93(6):673-689. doi: 10.1086/628995 |
[29] | Bonin B. A-Type Granites and Related Rocks:Evolution of a Concept, Problems and Prospects[J]. Lithos, 2007, 97(12):1-29. |
[30] | 马国祥, 王之晟, 郝晓飞, 等.阿尔山地区金江沟高分异I型花岗岩锆石U-Pb年龄、岩石地球化学及构造意义[J].世界地质, 2016, 35(1):89-99. doi: 10.3969/j.issn.1004-5589.2016.01.009 |
[31] | Loiselle M C, Wones D R. Characteristic and Origin of Anorogennic Granites[J]. Geological Society of America Abstracts with Programs, 1979, 11(7):468. |
[32] | Collins W J, Beams S D, White A J R, et al. Nature and Origin of A-Type Granites with Particular Reference to Southeastern Australia[J]. Contrib. Mineral. Petrol., 1982, 80:189-200. doi: 10.1007/BF00374895 |
[33] | Whalen J B, Currie K L, Chappell B W. A-Type Granites:Geochemical Characteristics, Discrimination and Petrogenesis[J]. Contributiongs to Mineralogy and Petrology, 1987, 95(4):407-419. doi: 10.1007/BF00402202 |
[34] | 邱检生, 王德滋, 蟹泽聪史, 等.福建沿海铝质A型花岗岩的地球化学及岩石成因[J].地球化学, 2000, (4):313-321. |
[35] | Hole M J, Saunders A D, Marriner G F, et al..Subduction of pelagic sediments:Implications for the prigin of Ceanomalous basalts from the Mariana island[J]. Journal of the Geological Society, 1984, 141(3):453-472. doi: 10.1016/0198-0254(84)93416-2 |
[36] | 王中刚.新疆北部花岗岩类成因类型及其与成矿的关系[J].新疆地质, 1994, (1):9-15. |
[37] | 徐新, 何国琦, 李华芹, 等.克拉玛依蛇绿混杂岩带的基本特征和锆石SHRIMP年龄信息[J].中国地质, 2006, 33(3):470-475. doi: 10.3969/j.issn.1000-3657.2006.03.003 |
[38] | 张弛, 黄萱.新疆西准噶尔蛇绿岩形成时代和环境的探讨[J].地质论评, 1992, 38(6):509-524. doi: 10.3321/j.issn:0371-5736.1992.06.009 |
[39] | 辜平阳, 李永军, 张兵, 等.西准达尔布特蛇绿岩中辉长岩LAICP-MS锆石U-Pb测年[J].岩石学报, 2009, 25(6):1364-1372. |
[40] | 陈博, 朱永峰.新疆达拉布特蛇绿混杂岩中辉长岩岩石学、微量元素地球化学和锆石U-Pb年代学研究[J].岩石学报, 2011, 27(6):1746-1758. |
[41] | Wang Z H, Sun S, Li J L, et al. Paleozoic tectonic evolution of the northern Xinjiang, China:Geochemical and geochronological constraints from the ophiolites[J].Tectonics, 2003, 22(2):1-15. |
[42] | Yang G X, Li Y J, Gu P Y, et al. Geochronological and geochemical study of the Darbut ophiolitic complex in the West Junggar (NW China):Implications for petrogenesis and tectonic evolution[J]. Gondwana Research, 2012, 21(4):1037-1049. doi: 10.1016/j.gr.2011.07.029 |
[43] | Yang G X, Li Y J, Santosh M, et al. A Neoproterozoic seamount in the Paleoasian Ocean:Evidence from zircon U-Pb geochronology and geochemistry of the Mayile ophiolitic melange in West Junggar, NW China[J]. Lithos, 2012, 140/141:53-65. doi: 10.1016/j.lithos.2012.01.026 |
[44] | Tang G J, Wang Q, Wyman D A, et al. Ridge subduction and crustal growth in the Central Asian Orogenic Belt:Evidence from Late Carboniferous adakites and high-Mg diorites in the western Junggar region, northern Xinjiang (west China)[J]. Chemical Geology, 2010, 277(34):281-300. doi: 10.1016/j.chemgeo.2010.08.012 |
[45] | Tang G J, Wang Q, Wyman D A, et al. Recycling oceanic crust for continental crustal growth:Sr-Nd-Hfisotope evidence from granitoids in the western Junggar region, NW China[J]. Lithos, 2012, 128/131:73-83. doi: 10.1016/j.lithos.2011.11.003 |
[46] | Tang G J, Wang Q, Wyman D A, et al. Late Carboniferous high εNd(t)-εHf(t) granitoids, enclaves and dikes in western Junggar, NW China:Ridge-subduction-related magmatism and crustal growth[J]. Lithos, 2012, 140/141:86-102. doi: 10.1016/j.lithos.2012.01.025 |
[47] | Zhou T F, Yuan F, Fan Y, et al. Granites in the Sawuer region of the West Junggar, Xinjiang Province, China:Geochronological and geochemical characteristics and their geodynamic significance[J]. Lithos, 2008, 106(34):191-206. doi: 10.1016/j.lithos.2008.06.014 |
Main tectonic map of Western Junggar, Xinjiang (a) and geological map of Jigentai area (b)
SiO2-(Na2O+K2O) (a), SiO2-K2O (b) and A/CNKA/NK (c) diagrams
Chondrite-normalized REE patterns (a) and primitive mantle normalized trace element patterns (b)
CL images and ages (a) and U-Pb concordia plots (b) from monzodiorite zircons
SiO2-P2O5(a) and SiO2-Pb (b) diagrams
SiO2-Ce(a) and K2O-Na2O (b) diagrams
Zircon in situ t-176Hf/177Hf and t-εHf(t)diagrams of monzodiorite
Y-Nb (a) and (Y+Nb)-Rb (b) diagrams