Petrology and Isotopic Chronology of Tagong Granite in Eastern Songpan-Ganzi Fold Belt and Its Tectonic Significance
-
摘要: 松潘-甘孜造山带东缘的三叠纪-侏罗纪中酸性花岗岩，如塔公岩体，为晚三叠世的碰撞造山以及燕山期的构造演化提供了重要信息.区域地质调查填图表明，塔公岩体为石英闪长岩、花岗闪长岩、黑云母二长花岗岩.其地球化学特征表明岩石主体属高钾钙碱性系列、准铝质-过铝质过渡系列，稀土配分曲线显示其轻稀土富集、重稀土亏损，具有壳源岩浆特征，稀土-微量元素投点结果表明花岗岩形成于造山时期后碰撞阶段.对塔公花岗岩体采集的4件同位素样品的年龄数据质量较高，为214±1 Ma、214±1 Ma、215±1 Ma、216±1 Ma；该组年龄可以作为限制印支晚期扬子、华北和昌都板块之间碰撞时限的证据.基于塔公花岗岩类的岩石地球化学特征、同位素年代学特征，结合区域研究资料，认为松潘-甘孜造山带东缘类似塔公岩体的晚三叠世花岗岩类形成于昌都、扬子和华北地块后碰撞阶段的岩石圈拆沉作用.Abstract: The Triassic-Jurassic intermediate-acid granites in the eastern Songpan-Ganzi fold belt, such as the Tagong granite, provide important information for the collisional orogeny of the Late Triassic and the tectonic evolution in Yanshanian. The regional geological survey map shows that the Tagong granite consists of quartz diorite, granodiorite, biotite monzonitic granite. Its geochemical characteristics indicate that the main body of the rock belongs to high-potassium-calcium-alkaline series and quasi-aluminum-over-aluminum transition. The rare earth element pattern shows that it is enriched in light rare earth and depleted in heavy rare earth. It has the characteristics of crust-derived magma. The rare earth-trace elements dosing results indicate that granite was formed in the post-collision stage of the orogenic period. The isotope samples collected from the Tagong granite obtained high-quality isotopic age, namely 214±1 Ma, 214±1 Ma, 215±1 Ma, 216±1 Ma, which can be used as evidences to limit the collision time among the Yangtze, North China and Changdu plates in the Triassic. Based on the geochemical characteristics and isotopic chronology of the Tagong granitoids, combined with the regional research data, it is considered that the Late Triassic granitoids similar to the Tagong granite in the eastern Songpan-Ganzi fold belt were formed due to the lithospheric delamination in the post-collision stage of Changdu, Yangtze and the North China plates.
-
Key words:
- Songpan-Ganzi fold belt /
- Tagong granite /
- granite /
- geochemistry /
- isotopic chronology /
- post-collision stage /
- delamination
-
图 1 塔公岩体大地构造位置及采样位置
Fig. 1. Tectonic location and sampling position of the Tagong granite
图 2 塔公岩体及围岩的地质图
Fig. 2. Schematic geological map of the Tagong granite and its surrounding rocks
图 4 塔公花岗岩镜下特征
a. 石英闪长岩；b. 花岗闪长岩；c、d. 黑云母二长花岗岩
Fig. 4. The microscope characteristics of Tagong granite
图 5 塔公花岗岩体主量元素图解
Fig. 5. Graphical diagrams of the main elements of the Tagong granite
图 7 塔公岩体锆石阴极发光图像
Fig. 7. Cathodoluminescence (CL) images for zircons of Tagong granite
图 8 塔公花岗岩类锆石U-Pb谐和图和加权平均年龄
Fig. 8. Zircon U-Pb harmonic diagrams and weighted mean ages of Tagong granite
图 9 塔公花岗岩体的构造环境判别图解
Fig. 9. Diagrams of tectonic environment discrimination of Tagong granite
表 1 样品信息
Table 1. Sample information
样品编号 样品用途 采样高程(m) 经度 纬度 岩石名称 PM17-14-1 主量、微量、稀土元素分析 4 171 101°35'21"E 30°12'16"N 灰色细粒石英闪长岩 PM17-14-2 主量、微量、稀土元素分析 4 171 101°35'21"E 30°12'16"N 灰色细粒石英闪长岩 PM17-19-1 主量、微量、稀土元素分析；锆石U-Pb同位素 4 209 101°35'12"E 30°12'30"N 灰色细-中粒花岗闪长岩 PM17-29-1 主量、微量、稀土元素分析；锆石U-Pb同位素 4 143 101°34'46"E 30°13'28"N 灰色细-中粒黑云母花岗闪长岩 PM17-30-1 主量、微量、稀土元素分析 4 152 101°34'37"E 30°13'31"N 灰白色中粒黑云母二长花岗岩 PM17-34-1 主量、微量、稀土元素分析 4 124 101°34'21"E 30°13'47"N 灰色中细粒黑云母花二长岗岩 PM17-43-1 主量、微量、稀土元素分析；锆石U-Pb同位素 4 024 101°34'00"E 30°14'46"N 灰白色细粒黑云母二长花岗岩 PM17-63-1 主量、微量、稀土元素分析；锆石U-Pb同位素 3 984 101°32'33"E 30°16'50"N 灰白色细粒花岗闪长岩 PM17-66-1 主量、微量、稀土元素分析 3 948 101°32'32"E 30°17'13"N 灰白色细粒花岗闪长岩 
下载: 导出CSV
-
[1] Coulon, C. , Megartsi, M. , Fourcade, S. , et al. , 2002. Post-Collisional Transition from Calc-Alkaline to Alkaline Volcanism during the Neogene in Oranie (Algeria): Magmatic Expression of a Slab Breakoff. Lithos, 62(3-4): 87-110. https://doi.org/10.1016/10.1016/s0024-4937(02)00109-3 [2] Duan, Z. M. , Li, Y. , Zhang, Y. , et al. , 2005. Zircon U-Pb Age, Continent Dynamics Significance and Geochemical Characteristics of the Mesozoic and Cenozoic Granites from the Tanggula Range in the Qinghai-Tibet Plateau. Acta Geologica Sinica, 79(1): 88-97(in Chinese with English abstract). http://www.researchgate.net/publication/283167372_Zircon_U-Pb_age_continent_dynamics_significance_and_geochemical_characteristics_of_the_Mesozoic_and_Cenozoic_granites_from_the_Tanggula_range_in_the_Qinghai-Tibet_Plateau [3] Duan, Z. M. , Zhang, Y. X. , Zhu, X. P. , et al. , 2013. Geochemistry and Isotopic Dating of the Mazicuo Quartz Diorites in the Southern Songpan-Ganzi Terrane and Its Tectonic Implications. Acta Geologica Sinica, 87(12): 1874-1886(in Chinese with English abstract). http://en.cnki.com.cn/Article_en/CJFDTOTAL-DZXE201312010.htm [4] Hu, J. M. , Meng, Q. R. , Shi, Y. R. , et al. , 2005. SHRIMP U-Pb Dating of Zircons from Granitoid Bodies in the Songpan-Ganzi Terrane and Its Implications. Acta Petrologica Sinica, 21(3): 867-880(in Chinese with English abstract). http://www.oalib.com/paper/1472623 [5] Ilbeyli, N. , Pearce, J. A. , Thirlwall, M. F. , et al. , 2004. Petrogenesis of Collision-Related Plutonics in Central Anatolia, Turkey. Lithos, 72(3-4): 163-182. https://doi.org/10.1016/10.1016/j.lithos.2003.10.001 [6] Jung, S. , Mezger, K. , Hoernes, S. , 1998. Petrology and Geochemistry of Syn- to Post-Collisional Metaluminous A-Type Granites: A Major and Trace Element and Nd-Sr-Pb-O-Isotope Study from the Proterozoic Damara Belt, Namibia. Lithos, 45(1-4): 147-175. https://doi.org/10.1016/10.1016/s0024-4937(98)00030-9 [7] Lai, S. C. , Zhao, S. W. , 2015. Geochemistry and Petrogenesis of Quartz Diorite in Tagong Area of Northwest Sichuan. Journal of Earth Sciences and Environment, 37(3): 1-13(in Chinese with English abstract). http://en.cnki.com.cn/Article_en/CJFDTotal-XAGX201503003.htm [8] Li, P. , Pei, X. Z. , Li, R. B. , et al. , 2019. Zircon U-Pb Geochronology, Geochemical Characteristics and Geological Significance of the Daan Granite in the Northwestern Margin of the Yangtze Block. Earth Science, 44(4): 1338-1356(in Chinese with English abstract). [9] Pan, G. T. , Xiao, Q. H. , Lu, S. N. , et al. , 2009. Subdivision of Tectonic Units in China. Geology in China, 36(1): 1-28(in Chinese with English abstract). http://www.researchgate.net/publication/284700316_Subdivision_of_tectonic_units_in_China [10] Roger, F. , Malavieille, J. , Leloup, P. H. , et al. , 2004. Timing of Granite Emplacement and Cooling in the Songpan-Garzê Fold Belt (Eastern Tibetan Plateau) with Tectonic Implications. Journal of Asian Earth Sciences, 22(5): 465-481. https://doi.org/10.1016/10.1016/s1367-9120(03)00089-0 [11] Shi, Z. L. , Zhang, H. F. , Cai, H. M. , 2009. Petrogenesis of Strongly Peraluminous Granites in Markan Area, Songpan Fold Belt and Its Tectonic Implication. Earth Science, 34(4): 569-584(in Chinese with English abstract). http://en.cnki.com.cn/Article_en/CJFDTOTAL-DQKX200904003.htm [12] Wan, C. H. , Yuan, J. , Li, F. X. , et al. , 2011. Late Triassic Granitoids in the Southern Part of the Songpan-Garze Fold Belt: Petrology, Geochemical Composition and Petrogenesis. Acta Petrologica et Mineralogica, 30(2): 185-198(in Chinese with English abstract). http://en.cnki.com.cn/Article_en/CJFDTOTAL-YSKW201102005.htm [13] Wu, F. Y. , Sun, D. Y. , Li, H. M. , et al. , 2002. A-Type Granites in Northeastern China: Age and Geochemical Constraints on Their Petrogenesis. Chemical Geology, 187(1-2): 143-173. https://doi.org/10.1016/10.1016/s0009-2541(02)00018-9 [14] Xiao, L. , Zhang, H. F. , Clemens, J. D. , et al. , 2007. Late Triassic Granitoids of the Eastern Margin of the Tibetan Plateau: Geochronology, Petrogenesis and Implications for Tectonic Evolution. Lithos, 96(3-4): 436-452. https://doi.org/10.1016/10.1016/j.lithos.2006.11.011 [15] Yuan, H. H. , Zhang, Z. L. , Zhang, P. , 1991. The Uplifting and Cooling Histories of Laojungou Granite in the Western Margin of the Central Section Mountain. Journal of Chengdu College of Geology, 18(1): 17-22(in Chinese with English abstract). http://en.cnki.com.cn/Article_en/CJFDTOTAL-CDLG199101003.htm [16] Yuan, H. L. , Gao, S. , Liu, X. M. , et al. , 2004. Accurate U-Pb Age and Trace Element Determinations of Zircon by Laser Ablation-Inductively Coupled Plasma-Mass Spectrometry. Geostandards and Geoanalytical Research, 28(3): 353-370. https://doi.org/10.1016/10.1111/j.1751-908x.2004.tb00755.x [17] Yuan, J. , Xiao, L. , Wan, C. H. , et al. , 2011. Petrogenesis of Fangmaping-Sanyanlong Granites in Southern Songpan-Garzê Fold Belt and Its Tectonic Implication. Acta Geologica Sinica, 85(2): 195-206(in Chinese with English abstract). http://en.cnki.com.cn/Article_en/CJFDTOTAL-DZXE201102006.htm [18] Zhang, H. F. , Parrish, R. , Zhang, L. , et al. , 2007. A-Type Granite and Adakitic Magmatism Association in Songpan-Garze Fold Belt, Eastern Tibetan Plateau: Implication for Lithospheric Delamination. Lithos, 97(3-4): 323-335. https://doi.org/10.1016/10.1016/j.lithos.2007.01.002 [19] Zhang, H. F. , Zhang, L. , Harris, N. , et al. , 2006. U-Pb Zircon Ages, Geochemical and Isotopic Compositions of Granitoids in Songpan-Garze Fold Belt, Eastern Tibetan Plateau: Constraints on Petrogenesis and Tectonic Evolution of the Basement. Contributions to Mineralogy and Petrology, 152(1): 75-88. https://doi.org/10.1016/10.1007/s00410-006-0095-2 [20] Zhang, Y. X. , Luo, Y. N. , Yang, C. X. , 1988. Panxi Rift. Geological Publishing House, Beijing (in Chinese). [21] Zhao, Y.J., 2007.Geochemistry, Petrogenesis and Tectonic Implications of Mesozoic Granitoids Intrusions in Eastern Songpan-Garzê (Dissertation). Guangzhou Institute of Geochemistry of Chinese Academy of Sciences, Guangzhou (in Chinese with English abstract). [22] Zhao, Y. J. , Yuan, C. , Zhou, M. F. , et al. , 2007. Post-Orogenic Extension of Songpan-Garzê Orogen in Early Jurassic: Constraints from Niuxingou Monzodiorite and Siguniangshan A-Type Granite of Western Sichuan, China. Geochimica, 36(2): 139-152(in Chinese with English abstract). http://en.cnki.com.cn/Article_en/CJFDTOTAL-DQHX200702003.htm [23] 段志明, 李勇, 张毅, 等, 2005. 青藏高原唐古拉山中新生代花岗岩锆石U-Pb年龄、地球化学特征及其大陆动力学意义. 地质学报, 79(1): 88-97. https://www.cnki.com.cn/Article/CJFDTOTAL-DZXE200501010.htm [24] 段志明, 张玉修, 祝向平, 等, 2013. 松潘-甘孜南部玛孜措石英闪长岩的地球化学特征、同位素年龄及其构造意义. 地质学报, 87(12): 1874-1886. https://www.cnki.com.cn/Article/CJFDTOTAL-DZXE201312010.htm [25] 胡健民, 孟庆任, 石玉若, 等, 2005. 松潘-甘孜地体内花岗岩锆石SHRIMP U-Pb定年及其构造意义. 岩石学报, 21(3): 867-880. https://www.cnki.com.cn/Article/CJFDTOTAL-YSXB200503027.htm [26] 赖绍聪, 赵少伟, 2015. 川西北塔公石英闪长岩地球化学特征和岩石成因. 地球科学与环境学报, 37(3): 1-13. https://www.cnki.com.cn/Article/CJFDTOTAL-XAGX201503003.htm [27] 栗朋, 裴先治, 李瑞保, 等, 2019. 扬子板块西北缘大安花岗岩体锆石U-Pb年代学、地球化学特征及其地质意义. 地球科学, 44(4): 1338-1356. doi: 10.3799/dqkx.2018.163 [28] 潘桂棠, 肖庆辉, 陆松年, 等, 2009. 中国大地构造单元划分. 中国地质, 36(1): 1-28. https://www.cnki.com.cn/Article/CJFDTOTAL-DIZI200901004.htm [29] 时章亮, 张宏飞, 蔡宏明, 2009. 松潘造山带马尔康强过铝质花岗岩的成因及其构造意义. 地球科学, 34(4): 569-584. http://www.earth-science.net/article/id/1861 [30] 万传辉, 袁静, 李芬香, 等, 2011. 松潘-甘孜造山带南段晚三叠世兰尼巴和羊房沟花岗岩岩石学、地球化学特征及成因. 岩石矿物学杂志, 30(2): 185-198. https://www.cnki.com.cn/Article/CJFDTOTAL-YSKW201102005.htm [31] 袁海华, 张志兰, 张平, 1991. 龙门山老君沟花岗岩的隆升及冷却史. 成都地质学院学报, 18(1): 17-22. https://www.cnki.com.cn/Article/CJFDTOTAL-CDLG199101003.htm [32] 袁静, 肖龙, 万传辉, 等, 2011. 松潘-甘孜南部放马坪-三岩龙花岗岩的成因及其构造意义. 地质学报, 85(2): 195-206. https://www.cnki.com.cn/Article/CJFDTOTAL-DZXE201102006.htm [33] 张云湘, 骆耀南, 杨崇喜, 1988. 攀西裂谷. 北京: 地质出版社. [34] 赵永久, 2007. 松潘-甘孜东部中生代中酸性侵入体的地球化学特征、岩石成因及构造意义(博士学位论文). 广州: 中国科学院广州地球化学研究所. [35] 赵永久, 袁超, 周美夫, 等, 2007. 松潘甘孜造山带早侏罗世的后造山伸展: 来自川西牛心沟和四姑娘山岩体的地球化学制约. 地球化学, 36(2): 139-152. https://www.cnki.com.cn/Article/CJFDTOTAL-DQHX200702003.htm -
点击查看大图
图(10) / 表(1)
计量
- 文章访问数: 673
- HTML全文浏览量: 260
- PDF下载量: 56
- 被引次数: 0
