Geochronology, geochemistry and geological significance of the Wulan composite pluton in the southern Xing'an block
-
摘要: 兴蒙造山带北缘晚古生代的构造格局,尤其是洋盆的闭合时限一直存在争议,兴安地块南的乌兰复合岩体为解决这一问题提供了一个良好的研究窗口。对乌兰复合岩体进行了锆石U-Pb测年与地球化学特征研究,确定了其形成时代与岩石成因,进而揭示了区域构造背景。乌兰复合岩体由细粒二长花岗岩和斑状二长花岗岩组成,前者构成了岩体的主体,成岩年龄为(312±2) Ma,形成时代为晚石炭世早期。地球化学特征显示: 细粒二长花岗岩和斑状二长花岗岩均具有全碱含量中等、富钾、过铝质的特征,为高钾钙碱性系列的高分异S型花岗岩,且细粒二长花岗岩的稀土含量偏低,负Eu异常更明显,显示了更高的分异演化特征; 细粒二长花岗岩和斑状二长花岗岩均富集大离子亲石元素(Rb、Th及K),显著亏损Ba、Sr、Ti等元素,弱亏损Ta、Nb等元素,具有相似的微量元素与稀土元素分布特征,指示二者来自于同一源区。乌兰复合岩体的形成与古亚洲洋的演化有关,形成于洋盆闭合后的造山晚期伸展环境。Abstract: There are some existing debates about the Late Paleozoic tectonic framework of the northern margin of the Xing'an-Mongolian orogenic belt, especially the final closing time of oceanic basin. Wulan composite Pluton in the southern Xing'an block provides a good medium to address this problem. In this paper, the Zircon LA-ICP-MS U-Pb ages and geochemical characteristics of Wulan composite Pluton were studied to determine its formation epoch and petrogenesis, and to reveal the regional tectonic setting. Wulan composite Pluton is composed of fine grained monzogranite and porphyritic monzogranite, the former constitutes the main body of the rock mass, with the diagenetic age of (312±2) Ma, which was formed in early Late Carboniferous. Geochemical analyses indicates that both of the fine grained monzogranite and porphyritic monzogranite have the characteristics of medium total alkali content, rich in K and peraluminous, belonging to highly fractionated S-type granite of high-K calc-alkaline series. The total REE contents of main rock mass of fine grained monzogranite are relatively low, with obvious negative Eu anomalies, showing high differential evolution character. Both the fine grained monzogranite and porphyritic monzogranite are rich in large ion lithophylic elements (Rb, Th and K), and obviously depleted in Ba, Sr and Ti, with slightly depleted in Ta and Nb. These two types of rocks have characterastics of similar trace and rare earth elements distribution, indicating that they come from the same source region. The formation of the rock mass is related to the evolution of the ancient Asian ocean and was formed in the late orogenic extensional environment after the oceanic basin was closed.
-
Key words:
- Wulan composite pluton /
- S-type granite /
- geochemistry /
- Xing'an Block /
- Paleo-Asian Ocean
-
-
[1] 徐备,王志伟,张立杨,等.兴蒙陆内造山带[J].岩石学报,2018,34(10):2819-2844.
[2] Xu B,Wang Z W,Zhang L Y,et al.The Xing-Meng intracontinent orogenic belt[J].Acta Petrol Sin,2018,34(10):2819-2844.
[2] 徐备,赵盼,鲍庆中,等.兴蒙造山带前中生代构造单元划分初探[J].岩石学报,2014,30(7):1841-1857.
[4] Xu B,Zhao P,Bao Q Z,et al.Preliminary study on the pre-Mesozoic tectonic unit division of the Xing-Meng Orogenic Belt (XMOB)[J].Acta Petrol Sin,2014,30(7):1841-1857.
[3] 许文良,孙晨阳,唐杰,等.兴蒙造山带的基底属性与构造演化过程[J].地球科学,2019,44(5):1620-1646.
[6] Xu W L,Sun C Y,Tang J,et al.Basement nature and tectonic evolution of the Xing'an-Mongolian orogenic belt[J].Earth Sci,2019,44(5):1620-1646.
[4] Xiao W J,Windley B F,Hao J,et al.Accretion leading to collision and the Permian Solonker suture,Inner Mongolia,China:Termination of the central Asian orogenic belt[J].Tectonics,2003,22(6):1069.
[5] Wu F Y,Sun D Y,Ge W C,et al.Geochronology of the Phanerozoic Granitoids in Northeastern China[J].J Asian Earth Sci,2011,41(1):1-30.
[6] 许文良,王枫,裴福萍,等.中国东北中生代构造体制与区域成矿背景:来自中生代火山岩组合时空变化的制约[J].岩石学报,2013,29(2):339-353.
[10] Xu W L,Wang F,Pei F P,et al.Mesozoic tectonic regimes and regional ore-forming background in NE China:Constraints from spatial and temporal variations of Mesozoic volcanic rock associations[J].Acta Petrol Sin,2013,29(2):339-353.
[7] 张晋瑞,魏春景,初航.兴蒙造山带构造演化的新模式:来自内蒙古中部四期不同类型变质作用的证据[J].岩石学报,2018,34(10):2857-2872.
[12] Zhang J R,Wei C J,Chu H.New model for the tectonic evolution of Xing'an-Inner Mongolia Orogenic belt:Evidence from four different phases of metamorphism in central Inner Mongolia[J].Acta Petrol Sin,2018,34(10):2857-2872.
[8] 王帅,李英杰,王金芳,等.内蒙古西乌旗晚石炭世马尼塔埃达克岩的发现及其对古亚洲洋东段洋内俯冲的约束[J].地质通报,2021,40(1):82-94.
[14] Wang S,Li Y J,Wang J F,et al.Discovery of Late Carboniferous adakite in Manita,Inner Mongolia,and its constrains on intra-oceanic subduction in eastern Paleo-Asian Ocean[J].Geol Bull China,2021,40(1):82-94.
[9] 李敏,李敏,程银行,等.内蒙古东乌旗晚古生代闪长岩、二长花岗岩年代学特征及岩石成因[J].中国地质,2016,43(2):380-394.
[16] Li M,Li M,Cheng Y H,et al.Chronology and petrogenesis of the diorite and monzonitic granite in Dong Ujimqin Banner,Inner Mongolia[J].Geol China,2016,43(1):380-394.
[10] 刘建峰,迟效国,张兴洲,等.内蒙古西乌旗南部石炭纪石英闪长岩地球化学特征及其构造意义[J].地质学报,2009,83(3):365-376.
[18] Liu J F,Chi X G,Zhang X Z,et al.Geochemical characteristic of Carboniferous quartz-diorite in the southern Xiwuqi area,Inner Mongolia and its tectonic significance[J].Acta Geol Sin,2009,83(3):365-376.
[11] 王金芳,李英杰,李红阳,等.贺根山缝合带白音呼舒奥长花岗岩锆石U-Pb年龄、地球化学特征及构造意义[J].地质论评,2019,65(4):857-872.
[20] Wang J F,Li Y J,Li H Y,et al.Zircon U-Pb ages and geoche-mical characteristics of Baiyinhushu trondhjemite in Hegenshan suture zone and their tectonic implications[J].Geol Rev,2019,65(4):857-872.
[12] 王树庆,胡晓佳,赵华雷,等.内蒙古京格斯台晚石炭世碱性花岗岩年代学及地球化学特征——岩石成因及对构造演化的约束[J].地质学报,2017,91(7):1467-1482.
[22] Wang S Q,Hu X J,Zhao H L,et al.Geochronology and geochemistry of Late Carboniferous Jinggesitai alkaline granites,Inner Mongolia:Petrogenesis and implications for tectonic evolution[J].Acta Geol Sin,2017,91(7):1467-1482.
[13] 程银行,李艳锋,李敏,等.内蒙古东乌旗碱性侵入岩的时代、成因及地质意义[J].地质学报,2014,88(11):2086-2096.
[24] Cheng Y H,Li Y F,Li M,et al.Geochronology and petrogenesis of the alkaline pluton,in Dong Ujimqi,Inner Mongolia and its tectonic implications[J].Acta Geol Sin,2014,88(11):2086-2096.
[14] 洪大卫,黄怀曾,肖宜君,等.内蒙古中部二叠纪碱性花岗岩及其地球动力学意义[J].地质学报,1994,68(3):219-230.
[26] Hong D W,Huang H Z,Xiao Y J,et al.The Permian alkaline granites in central Inner Mongolia and their geodynamic significance[J].Acta Geol Sin,1994,68(3):219-230.
[15] 童英,洪大卫,王涛,等.中蒙边境中段花岗岩时空分布特征及构造和找矿意义[J].地球学报,2010,31(3):395-412.
[28] Tong Y,Hong D W,Wang T,et al.Spatial and temporal distribution of granitoids in the middle segment of the Sino-Mongolian Border and its tectonic and metallogenic implications[J].Acta Geoscient Sin,2010,31(3):395-412.
[16] 张超,吴新伟,刘永江,等.大兴安岭中段早二叠世A型花岗岩成因及对扎兰屯地区构造演化的制约[J].岩石学报,2020,36(4):1091-1106.
[30] Zhang C,Wu X W,Liu Y J,et al.Genesis of Early Permian A-type granites in the middle of the Great Xing'an Range and constraints on tectonic evolution of the Zhalantun area[J].Acta Petrol Sin,2020,36(4):1091-1106.
[17] Ludwig K R.Isoplot 3.0:A Geochronological Toolkit for Microsoft Excel[M].Berkeley Geochronology Center,2003(4):1-70.
[18] 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,2004,49(16):1589-1604.
[33] Wu Y B,Zheng Y F.Genesis of zircon and its constraints on interpretation of U-Pb age[J].Chin Sci Bull,2004,49(15):1589-1604.
[19] Le Maitre R W,Streckeisen A,Zanettin B,et al.Igneous Rocks:A Classification and Glossary of Terms[J].2nd ed.Cambridge:Cambridge University Press,2002:33-39.
[20] Morrison G W.Characteristics and tectonic setting of the shoshonite rock association[J].Lithos,1980,13(1):97-108.
[21] Maniar P D,Piccoli P M.Tectonic discrimination of granitoids[J].GSA Bull,1989,101(5):635-643.
[22] Sun S S,McDonough W F.Chemical and isotopic systematics of oceanic basalts:Implications for mantle composition and proce-sses[J].Geolog Soc London Spec Publicat,1989,42(1):313-345.
[23] 张天福,郭硕,辛后田,等.大兴安岭南段维拉斯托高分异花岗岩体的成因与演化及其对Sn-(Li-Rb-Nb-Ta)多金属成矿作用的制约[J].地球科学,2019,44(1):248-267.
[39] Zhang T F,Guo S,Xin H T,et al.Petrogenesis and magmatic evolution of highly fractionated granite and their constraints on Sn-(Li-Rb-Nb-Ta) mineralization in the Weilasituo deposit,Inner Mongolia,southern Great Xing'an Range,China[J].Earth Sci,2019,44(1):248-267.
[24] 舒徐洁,陈志洪,朱延辉,等.赣南兴国东固高分异花岗岩成因及地质意义[J].地质论评,2018,64(1):108-126.
[41] Shu X J,Chen Z H,Zhu Y H,et al.Genesis of Donggu highly fractionated granites,Xingguo,southern Jiangxi,and its geological significance[J].Geol Rev,2018,64(1):108-126.
[25] Whalen J B,Currie K L,Chappell B W.A-type granites:Geochemical characteristics,discrimination and petrogenesis[J].Contribut Mineral Petrol,1987,95(4):407-419.
[26] Sylvester P J.Post-collisional alkaline granites[J].J Geol,1989,97(3):261-280.
[27] 吴福元,刘小驰,纪伟强,等.高分异花岗岩的识别与研究[J].中国科学:地球科学,2017,47(7):745-765.
[45] Wu F Y,Liu X C,Ji W Q,et al.Highly fractionated granites:Reco-gnition and research[J].Sci China Earth Sci,2017,47(7):745-765.
[28] Chappell B W.Aluminium saturation in I- and S-type granites and the characterization of fractionated haplogranites[J].Lithos,1999,46(3):535-551.
[29] 李献华,李武显,李正祥.再论南岭燕山早期花岗岩的成因类型与构造意义[J].科学通报,2007,52(9):981-992.
[48] Li X H,Li W X,Li Z X.Re-discussion on genetic types and tectonic significance of Early Yanshan granites in Nanling[J].Chin Sci Bull,2007,52(9):981-992.
[30] 王德滋,刘昌实,沈渭洲,等.桐庐I型和相山S型两类碎斑熔岩对比[J].岩石学报,1993,9(1):44-54.
[50] Wang D Z,Liu C S,Shen W Z,et al.The contrast between tonglu I-Type and Xiangshan S-Type clastoporphyritic lava[J].Acta Petrol Sin,1993,9(1):44-54.
[31] Allègre C J,Minster J F.Quantitative models of trace element behavior in magmatic processes[J].Earth Plant Sci Lett,1978,38(1):1-25.
[32] Wu F Y,Jahn B M,Wilde S A,et al.Highly fractionated I-type granites in NE China (I).Geochronology and petrogenesis[J].Lithos,2003,66(3/4):241-273.
[33] 崔芳华,郑常青,徐学纯,等.大兴安岭全胜林场地区晚石炭世岩浆活动研究:对兴安地块与松嫩地块拼合时间的限定[J].地质学报,2013,87(9):1247-1263.
[54] Cui F H,Zheng C Q,Xu X C,et al.Late Carboniferous magmatic activities in the Quanshenglinchang area,great Xing'an range:Constrains on the timing of amalgamation between Xing'an and Songnen Massifs[J].Acta Geol Sin,2013,87(9):1247-1263.
[34] 张彦龙,葛文春,高妍,等.龙镇地区花岗岩锆石U-Pb年龄和Hf同位素及地质意义[J].岩石学报,2010,26(4):1059-1073.
[56] Zhang Y L,Ge W C,Gao Y,et al.Zircon U-Pb ages and Hf isotopes of granites in Longzhen area and their geological implica-tions[J].Acta Petrol Sin,2010,26(4):1059-1073.
[35] Pearce J A,Harris N B W,Tindle A G.Trace element discrimination diagrams for the tectonic interpretation of granitic rocks[J].J Petrol,1984,25(4):956-983.
[36] Batchelor R A,Bowden P.Petrogenetic interpretation of granitoid rock series using multicationic parameters[J].Chem Geol,1985,48(1/2/3/4):43-55.
[37] Brown G C,Nordin G L.An epizootic model of an insect-fungal pathogen system[J].Bull Mathemat Biol,1982,44(5):731-739.
-
计量
- 文章访问数: 715
- PDF下载数: 53
- 施引文献: 0
下载: