内蒙古中部红格尔图地区花岗岩的成因及构造背景——LA-ICP-MS锆石U-Pb年龄、地球化学的制约
Petrogenesis and tectonic setting of the granites in Honggeertu area, central Inner Mongolia: Constraints from LA-ICP-MS zircon U-Pb chronology and geochemistry
-
摘要: 内蒙古察右后旗红格尔图花岗岩岩体位于索伦缝合带以南,主要为正长花岗岩和二长花岗岩,富硅(70.44%~78.80%),富碱(7.46%~10.74%),贫镁、铁、钛等,A/CNK值在0.95~1.41之间,碱铝指数AKI值在0.68~0.97之间,碱度率AR值在3.30~6.68之间,为弱过铝质-过铝质类碱性系列花岗岩;稀土元素总量变化范围大,轻稀土元素富集,重稀土元素亏损,Eu呈负异常(δEu=0.03~0.89);富集高场强元素Th、U、Hf、Ta、Y等,亏损大离子亲石元素Sr、Ba、Eu等;高场强元素和值((Zr+Nb+Ce+Y)<350×10-6)明显偏低,该岩体属于高分异I型花岗岩,形成于后造山(后碰撞)伸展构造环境。LA-ICP-MS锆石同位素测年,获得锆石206Pb/238U年龄加权平均值分别为267.2±1.4Ma、269.2±1.6Ma和272.1±1.2Ma,表明该岩体形成于中二叠世,因此研究区内两大板块碰撞缝合的时间应该至少早于该岩体的形成时代,即应该至少早于267.2~272.1Ma。Abstract: Honggeertu granites, located in central Inner Mongolia and belonging to southern Solon-Linxi fault, is mainly composed of middle-fine to middle-coarse grained syenite granites and monzonitic granites. These granites have high SiO2 (70.44%~78.80%) and are enriched in alkali (Na2O+K2O=7.46%~10.74%) but depleted in Mg, Fe and Ti. The A/CNK ratios are in the range of 0.95~1.41, alkali aluminum indexes (AKI) are 0.68~0.97, and alkalinities (AR) are 3.30~6.68, suggesting that the granites belong to weakly peraluminous-peraluminous alkaline series. The granite intrusion has widely varying total REE values (ΣREE=25.96×10-6~654.50×10-6), and is enriched in LREE and depleted in HREE with negative Eu anomaly (δEu=0.03~0.89). It is relatively enriched in high field strength elements (Th, U, Hf, Ta and Y) and depleted in large ion lithophile elements (Ba, Eu and Sr). The values of high field strength elements (Zr+Nb+Ce+Y) are higher than 350×10-6. The rocks belong to highly fractionated I-type granites formed in a post orogenic tectonic environment. Zircon LA-ICP-MS dating yielded 206Pb/238U weighted average ages, i.e., 267.2Ma±1.4Ma (MSWD=1.5), 269.2±1.6Ma (MSWD=1.7) and 272.1±1.2Ma (MSWD=0.38), indicating that the rock was formed in the Middle Permian. The new data suggest that the collision between NCC and Siberian Craton was earlier than the formation of the rock, and should be at least as early as 267.2~272.1Ma.
-
Key words:
- Honggeertu granites /
- chronology /
- geochemistry /
- post-collision /
- structure /
- Inner Mongolia
-
-
[1] 邵济安. 内蒙古中部早古生代蛇绿岩及其在恢复地壳演化历史中的意义[C]//中国北方板块构造论文集Ⅰ. 北京:地质出版社, 1986:158-171.
[2] 唐克东, 张允平. 内蒙古缝合带的构造演化[C]//古中亚复合巨型缝合带南缘构造演化. 北京:科学技术出版社, 1991:30-54.
[3] 内蒙古自治区地质矿产局. 内蒙古自治区区域地质[M]. 北京:地质出版社, 1991:427-439.
[4] Xu B, Chen B, Shao J A. Sm-Nd and Rb-Sr isotopic geochronology of the Xilin Gol complex, Inner Mongolia[J]. Chinese Science Bulletin, 1996, 41(13):1107-1110.
[5] 郝旭,徐备. 内蒙古锡林浩特锡林郭勒杂岩的原岩年代和变质年代[J]. 地质评论, 1997, 43(1):101-105.
[6] Chen B, Jahn B M, Wilde S, et al. Two contrasting Paleozoic magmatic belts in northern Inner Mongolia, China:petrogenesis and tectonic implications[J]. Tectonophysics, 2000, 328:157-182.
[7] 徐备, Chorvet J, 张福勤. 内蒙古北部苏尼特左旗蓝片岩岩石学和年代学研究[J]. 地质科学, 2001, 36(4):424-434.
[8] Wu F Y, Sun D Y, Li H, et al. A-type granites in northeastern China:Age and geochemical constraints on their petrogenesis[J]. Chem. Geol., 2002, 187:143-173.
[9] Xiao W J, Windly 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):1069-1089.
[10] 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.
[11] 邵济安. 中朝板块北缘中段地壳演化[M]. 北京:北京大学出版社, 1991:1-136.
[12] 徐备,陈斌. 内蒙古北部华北板块与西伯利亚板块之间中古生代造山带的结构和演化[J]. 中国科学(D辑), 1997, 27(3):227-232.
[13] 王荃. 内蒙古中部中朝与西伯利亚古板块间缝合线的确定[J]. 地质学报, 1986, 1:3-43.
[14] 孙德有,吴福元,张艳斌,等. 西拉木伦河-长春-延吉板块缝合带的最后闭合时间——来自吉林大玉山花岗岩体的证据[J]. 吉林大学学报(地球科学版), 2004, 34(2):174-181.
[15] 陈斌. 内蒙古兴安地区二叠系沉积特征及构造背景[D].中国地质大学(北京)硕士学位论文, 2011:30-53.
[16] Steckeisen A. To each plutonic rock its proper name[J]. Earth-Sci. Rev., 1979, 12:1-33.
[17] Le Maitre R W, Bateman P, Dudek A, et al. A classification of igneous rocks and glossary of terms[M]. Blackwell, Oxford, 1989.
[18] Anderson T. Correction of common of common lead in U-Pb analyses that do not report 204Pb[J]. Chemical Geology, 2002, 192:59-79.
[19] Ludwig K R. Isoplot-A plotting and regression program for radiogenic-isotope date[J]. US Geological Survey Open-File Report, 1991, 39:91-445.
[20] 李怀坤,耿建珍,郝爽,等. 用激光烧蚀多接收器等离子体质谱仪(LA-MC-ICPMS)测定锆石U-Pb同位素年龄的研究[J]. 矿物学报, 2009, S1:600-601.
[21] William I S, Buick A, Cartwright I. An extended episode of early Mesoproterozoic metamorphic fluid flow in the Reynold Region Central Australia[J]. Journal of Metamorphic Geology, 1996, 14:29-47.
[22] 邓晋福,罗照华,苏尚国,等. 岩石成因、构造环境与成矿作用[M]. 北京:地质出版社, 2004.
[23] Whalen J B, Currie K L, Chappell B W. A-type granites:geochemical characteristics, discrimination and petrogenesis[J]. Contrib. Min. Petrol., 1987, 95:407-419.
[24] Whalen J B, Currie K L, Chappell B W, et al. Characterization and origin of aluminous A-type granites from the Lachlan Fold belt, southeastern Australia[J]. Petrol., 1997, 38:371-391.
[25] Chappell B W, White A J R. Two contrasting granite types:25 years later[J]. Australian Journal of Earth Sciences, 2001, 48:489-499.
[26] Chappell B W. A luminum saturation in I- and S-type granite and the characterization of fractionated haplogranite[J]. Lithos, 1999, 46:535-551.
[27] 邱检生,胡建,王孝磊,等. 广东河源白石冈岩体:一个高分异的I型花岗岩[J]. 地质学报, 2005, 79(4):503-514.
[28] 邱检生,肖娥,胡建,等. 福建北东沿海高分异I型花岗岩的成因:锆石U-Pb年代学、地球化学和Nd-Hf同位素制约[J]. 岩石学报, 2008, 24(11):2468-2484.
[29] 路凤香,桑隆康,邬金华, 等. 岩石学[M]. 北京:地质出版社, 2002.
[30] Chappell B W, White A J R. Two contrasting granite types[J]. Pacific Geology, 1974, 8:173-174.
[31] 高秉璋,洪大卫,郑基俭,等. 花岗岩类区1:5万区域地质填图方法指南[M]. 武汉:中国地质大学出版社, 1991.
[32] Harrison T M, Grove M, Mckeegan K D, et al. Origin and episodic emplacement of the Manaslu intrusive complex, central Himalayan[J]. Journal of Petrology, 1999, 40:3-19.
[33] Arth J G. Behaviour of trace elements during magmatic processes:a summary of theoretical models and their applications[J]. J. Res. U. S. Geol. Survey, 1976, 4:41-47.
[34] Hanson G N. The application of trace elements to the petrogenesis of igneous rocks of granitic compositions[J]. Earth and Planetary Science Letters, 1978, 38:26-43.
[35] 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, 66:241-273.
[36] 王涛. 花岗岩研究与大陆动力学[J]. 地学前缘, 2000, 7(增刊):137-146.
[37] 吴福元,孙德有,林强. 东北地区显生宙花岗岩的成因和地壳增生[J]. 岩石学报, 1999, 15(2):181-189.
[38] 柳长峰,周志广,张华锋,等. 内蒙古四子王旗乌尔塔高勒庙岩体的侵位时代及岩石地球化学特征[J]. 矿物岩石, 2011, 31(4):34-43.
[39] 蒋孝君,刘正宏,徐仲元,等. 内蒙古镶黄旗乌兰哈达中二叠世碱长花岗岩锆石U-Pb年龄和地球化学特征[J]. 地质通报, 2013, 32(11):1760-1768.
[40] 贺锋,许立权,苏宏伟,等. 内蒙古西部甜水井地区中二叠世A型花岗岩[J]. 西北地质, 2004, 37(3):7-14.
[41] 赵磊,吴泰然,罗红玲. 内蒙古乌拉特中旗北七哥陶辉长岩SHRIMP锆石U-Pb年龄、地球化学特征及其地质意义[J]. 岩石学报, 2011, 27(10):3071-3082.
[42] 洪大卫,王涛,童英. 中国花岗岩概述[J]. 地质论评, 2007, 53(增刊):9-16.
[43] Boynton W V. Cosmochemistry of the rare earth elements:meteorite studies[C]//Henderson P. Rare Earth Element Geochemistry. Elsecier, Amsterdam, 1984:63-114.
[44] McDonough W F, Sun S S. Isotopic and geochemical systematic in Tertiary-Recent basalts from southeastern Australia and implication for the sub-continental lithosphere[J]. Geochimica et Cosmochimica Acta, 1985, 49:2051-2067. ①内蒙古自治区地质局区域测量队. 镶黄旗幅1:20万区域地质调查报告. 1976. ②内蒙古自治区地质局区域测量队. 商都幅1:20万区域地质调查报告. 1971. ③内蒙古自治区地质局区域测量队. 三道沟幅1:20万区域地质调查报告. 1967.
-
计量
- 文章访问数: 706
- PDF下载数: 45
- 施引文献: 0
下载: