THE LATE MESOZOIC EXTENSION-SLIPPING-CONTRACTION OF THE ERLANGPING GROUP IN THE NORTH QINLING TECTONIC BELT, CENTRAL CHINA
-
摘要: 晚中生代, 中朝、扬子两地块的拼合带进一步受到强烈的陆内构造-岩浆活动改造, 为揭示其规律性, 以拼合带上北秦岭二郎坪群主体地块为研究对象, 综合开展了中小构造解析、显微构造岩组学、电子探针、年代学等研究。研究发现, 二郎坪群主体内部的小寨-二郎坪剪切带具右行韧性走滑特征, 大庙-湾潭剪切带具右行韧性走滑兼后期脆-韧性逆掩叠加的特征; 40Ar/39Ar构造-热年代学分析揭示出一期连续抬升-剥露过程, 时间介于~ 121 Ma和~ 100 Ma之间。晚中生代二郎坪群地块经历了伸展-走滑-收缩背景依次控制下的构造改造过程, 先是在区域伸展体制下, 被内部的小寨-二郎坪剪切带、大庙-湾潭剪切带切割为抱树坪岩片、火神庙岩片、二进沟岩片等构造岩片; 在其后的早白垩世早期区域走滑背景下, 各构造岩片又发生了平移为主的右行走滑运动; 最后, 二郎坪岩体的侵入终止了内部小寨-二郎坪剪切带的活动, 而大庙-湾潭剪切带也在区域收缩体制下终止活动, 从而使二郎坪群重又焊接为一体。研究结果预示着北秦岭二郎坪群晚中生代同时期的构造体制可能与大别山是相反的。Abstract: The convergence belt between the Sino-Korea block and the Yangtze block was strongly deformed by intracontinental tectonomagmatic activity in the Late Mesozoic.In order to show details of the belt during the Late Mesozoic, we have carried out a series of analysis for the Erlangping Group on mesosmall structure, micro-texture, electron-probe and geochronology.The study has recognized a ductile right lateral slipping deformation for the Xiaozhai-Erlangping shear zone inside the Erlangping Group, and a superimposion of ductile right lateral slipping and late brittle-ductile thrusting for the Damiao-Wantan shear zone.40Ar/39Ar tectonic-thermal chronological analysis reveals a continuous uplifting-denudating course between ~ 121 Ma and ~ 100 Ma.During the Late Mesozoic, the Erlangping Group experienced the tectonic reworkings respectively under the extensional, slipping and contractional tectonic regimes. Firstly, under the regionally extensional condition, the Erlangping Group was split by the XiaozhaiErlangping and Damiao-Wantan shear zones into three slabs, namely the Baoshuping, Huoshenmiao, and Erjingou slabs.Then in Early Cretaceous a right lateral movement of the slabs happened under a slipping regime.The intrusion of the Erlangping rock body ended the Xiaozhai-Erlangping shear zone, and the Damiao-Wantan shear zone was stopped under a contractional tectonic regime, which made the Erlangping Group welded into a single block again.Our results also indicated that the tectonic evolution of the Erlangping Group of the North Qinling in the Late Mesozoic processed in an opposite way to that of the Dabieshan tectonic belt.
-
Key words:
- Late Mesozoic /
- the Erlangping Group /
- tectonic slab /
- shear zone /
- 40Ar/39Ar geochronology /
- tectonic regime
-
图 2 中坪南二云母片岩显微构造
强烈叶理化改造, 发育云母C-C'劈理构造, 即发育两期云母, 早期为黑云母C面理, 晚期为白云母(绢云母)C'面理。薄片号Q0414a (图 1D, 点0414), 薄片恢复产状为北西-南东走向、直立倾角; CPL—正交偏光, PPL—单偏光。下同
Figure 2. Micro-structure of muscovite-biotite schist from Zhongping village
图 3 小寨-二郎坪韧性剪切带内糜棱岩三维显微构造模型
同一糜棱岩样品(图 1D, 点0414), 薄片Q0414-1a、Q0414-1b模型由两张恢复产状的互相垂直薄片的正交偏光显微照片拼合而成, 表现出伸展型C-C'构造的发育特点, C'内常见新生矿物白云母, 指示遭受了沿主剪切面C的右行平移剪切
Figure 3. 3D micro-structural model for mylonite from the Xiaozhai-Erlangping Ductile Shear Zone
图 4 大庙-湾潭剪切带的显微右行剪切运动学标志
千糜岩样品Q0403-1 (图 1C, 湾潭附近采样点0403)正交偏光照片, 显示了C-C'构造指示右行剪切的特点
Figure 4. Micro-dextral shearing marks along the Damiao-Wantan Shear Zone
图 5 朱阳关-夏馆韧性剪切带小水-马蹄湾一带的糜棱岩显微岩组学分析
眼球状长英质糜棱岩样品Q0421-7 (图 1D点0421)正交偏光照片。眼球状长石残斑较多, 波状消光, 与细粒化长石基质构成残斑系。石英主要以聚晶条带样式呈现, 其中细小单晶又多表现为细晶弱变形状态。下半球等面积投影石英c轴组构极密类型为较大的Ⅲ型极密(菱面滑移)和较小的Ⅷ型极密(底面滑移)。结合显微鉴定及产状恢复, 可判断出两个明显的韧性变形阶段:一为大极密所指示的大规模上盘指向北西的中温下降改造, 二为小极密所指示的局部性上盘指向南东的低温抬升改造过程
Figure 5. Micro-texture analysis of mylonite from Xiaoshui-Matiwan area along the Zhuyangguan-Xiaguan Shear Zone
图 6 朱阳关-夏馆剪切带子母沟糜棱岩显微构造分析
糜棱岩样品Q4124 (图 1B点4124)正交偏光显微照片。石英呈聚晶条带状, 单晶已定向拉长。下半球等面积投影石英c轴组构图显示极密类型为Ⅲ型极密(中温菱面滑移)和Ⅴ型极密(高温柱面滑移)。结合显微鉴定及产状恢复, 可判断出两个明显的韧性变形阶段:一为Ⅲ型极密所指示的上盘向北的中温构造伸展, 二为Ⅴ型极密所指示的上盘向南的高温抬升缩短
Figure 6. Micro-texture analysis of mylonite from Zimugou located in the Zhuyangguan-Xiaguan Shear Zone
图 7 瓦穴子-乔端剪切带(F2)糜棱岩显微构造分析
马连一带糜棱岩显微照片(左为单偏光, 中为正交偏光, 图 1B采样点0523)显示长英质S-C糜棱岩结构, 示右行剪切。S-C夹角13°, C-C′夹角26°
Figure 7. Micro-structural analysis of mylonite from the Waxuezi-Qiaoduan Shear Zone
图 8 Q0420-1黑云母40Ar/39Ar坪年龄谱(左)和等时年龄(右)
Figure 8. 40Ar/39Ar plateau age (left)and isochron age (right)of biotite from Sample Q0420-1
表 1 样品Q0420-1黑云母40Ar/39Ar阶段升温测年数据
Table 1. 40Ar/39Ar aging data of biotite from Sample Q0420-1
-
[1] 张二朋.秦巴及邻区地质-构造特征概述[M].北京:地质出版社, 1993.1~291.ZHANG Er-peng.Geologic-tectonic features of Qinling-Dabashan Mountains and adjacent regions[M].Beijing :Geological Publishing House, 1993.1~291. [2] 刘国惠, 张寿广, 游振东, 等.秦岭造山带主要变质岩群及其变质演化[M].北京:地质出版社, 1993.1~190.LIU Guo-hui, ZHANG Shou-guang, YOU Zhen-dong, et al.Main metamorphic groups and their metamorphic evolution of Qinling Orogen[M].Beijing :Geological Publishing House, 1993.1~190. [3] 张复新, 杜孝华, 王伟涛, 等.秦岭造山带及邻区中生代地质演化与成矿作用响应[J].地质科学, 2004, 39 (4):486~495. http://d.old.wanfangdata.com.cn/Periodical/dzkx200404004ZHANG Fu-xin, DU Xiao-hua, WANG Wei-tao, et al.Mineralization responded to Mesozoic geological evolution of the Qinling Orogen and its environs[J].Chinese Journal of Geology, 2004, 39 (4):486~495. http://d.old.wanfangdata.com.cn/Periodical/dzkx200404004 [4] 姜春发.中央造山带主要地质构造特征[J].地学研究, 1993, 27:107~108. http://cdmd.cnki.com.cn/Article/CDMD-11941-2009176630.htmJIANG Chun-fa.Major geological and structural characteristics of the Central Orogenic Belts, China[J].Geoscience Research, 1993, 27:107~108. http://cdmd.cnki.com.cn/Article/CDMD-11941-2009176630.htm [5] 张国伟, 张本仁, 袁学诚, 等.秦岭造山带与大陆动力学[M].北京:科学出版社, 2001.1~855.ZHANG Guo-wei, ZHANG Ben-ren, YUAN Xue-cheng, et al.Qinling orogen and continental dyanmics[M].Beijing :Science Press, 2001, 1~855. [6] 索书田, 钟增球, 周汉文, 等.中国中央造山带内两个超高压变质带关系[J].地质学报, 2004, 78 (2):156~165. http://www.cnki.com.cn/Article/CJFDTOTAL-DZXE200402002.htmSUO Shu-tian, ZHONG Zeng-qiu, ZHOU Han-wen, et al.On the relationship between the two UHP metamorphic belts in the Central Orogenic Belt, China[J].Acta Geologica Sinica, 2004, 78 (2):156~165. http://www.cnki.com.cn/Article/CJFDTOTAL-DZXE200402002.htm [7] 杨文采.中央造山带东段岩石圈的构造格架[J].中国地质, 2005, 32 (2):299~309. http://d.old.wanfangdata.com.cn/Periodical/zgdizhi200502013YANG Wen-cai.Tectonic framework of the eastern segment of the central orogenic belt of China[J].Chinese Geology, 2005, 32 (2):299~309. http://d.old.wanfangdata.com.cn/Periodical/zgdizhi200502013 [8] 许志琴, 杨经绥, 李海兵, 等.中央造山带早古生代地体构架与高压超高压变质带的形成[J].地质学报, 2006, 80 (12):1793~1806. doi: 10.3321/j.issn:0001-5717.2006.12.002XU Zhi-qin, YANG Jing-sui, Li Hai-bing, et al.The Early Paleozoic terrene framework and the formation of the high-pressure (HP)and ultra-high pressure (UHP)metamorphic belts at the Central Orogenic Belt (COB)[J].Acta Geologica Sinica, 2006, 80 (12):1793~1806. doi: 10.3321/j.issn:0001-5717.2006.12.002 [9] 赵亚曾, 黄汲清.秦岭山及四川之地质研究[J].地质专报甲种第9号, 1931.ZHAO Ya-zeng, HUANG Ji-qing.Geological research of Qinling Mountain and Sichuan[J].Geological Survey in China (Series A, No.9), 1931. [10] 肖思云, 张维吉, 宋子季, 等.北秦岭变质地层[M].西安:西安交通大学出版社, 1988.1~320.XIAO Si-yun, ZHANG Wei-ji, SONG Zi-ji, et al.Metamorphic stratigraphy in North Qinling[M].Xi'an:Xi'an Jiaotong University Press, 1988.1~320. [11] 赵宗溥.试论陆内型造山作用———以秦岭-大别山造山带为例[J].地质科学, 1995, 30 (1):19~28. http://www.cqvip.com/Main/Detail.aspx?id=1712474ZHAO Zong-pu.An introcontinental-type orogeny :Evidence from Qinling-Dabie orogenic belt, China[J].Scientia Geologica Sinica, 1995, 30 (1):19~28. http://www.cqvip.com/Main/Detail.aspx?id=1712474 [12] 刘军. 东秦岭二郎坪群变质作用[D]. 北京: 北京大学, 1987.LIU Jun. Erlangping metamorphism in the eastern Qinling[D]. Beijing : Peking University, 1987. [13] 张阿利, 魏春景, 田伟, 等.北秦岭二郎坪群低压变质作用研究[J].岩石矿物学杂志, 2004, 23 (1):26~36. http://www.cnki.com.cn/Article/CJFDTOTAL-YSKW200401003.htmZHANG A-li, WEI Chun-jing, TIAN Wei, et al.Low-pressure metamorphism of Erlangping Group in North Qinling Mountains [J].Acta Petrologica Et Mineralogica, 2004, 23 (1):26~36. http://www.cnki.com.cn/Article/CJFDTOTAL-YSKW200401003.htm [14] 胡能高, 赵东林, 徐柏青, 等.北秦岭含柯石英榴辉岩的发现及其意义[J].科学通报, 1994, 21:2013. http://www.cnki.com.cn/Article/CJFDTOTAL-KXTB199421027.htmHU Neng-gao, ZHAO Dong-lin, XU Bai-qing, et al.The discovery of Coesite-bearing eclogite and its significance in North Qinling [J].Chinese Science Bullitin, 1994, 21:2013. http://www.cnki.com.cn/Article/CJFDTOTAL-KXTB199421027.htm [15] 游振东, 韩郁菁, 杨巍然, 等.东秦岭大别高压超高压变质带[M].武汉:中国地质大学出版社, 1998.1~157.YOU Zhen-dong, HAN Yu-jing, YANG Wei-ran, et al.High pressure and ultra-high pressure metamorphic belt in East Qinling [M].Wuhan:Press of China University of Geosciences, 1998.1~157. [16] 杨经绥, 许志琴, 裴先治, 等.秦岭发现金刚石:横贯中国中部巨型超高压变质带新证据及古生代和中生代两期深俯冲作用的识别[J].地质学报, 2002, 76 (4):484~495. http://d.old.wanfangdata.com.cn/Periodical/dizhixb200204007YANG Jing-sui, XU Zhi-qin, PEI Xian-zhi, et al.Discovery of diamond in North Qinling :Evidence for a giant UHPM belt across central China and recognition of Paleozoic and Mesozoic dual deep subduction between North China and Yangtze Plates[J].Acta Geologica Sinica, 2002, 76 (4):484~495. http://d.old.wanfangdata.com.cn/Periodical/dizhixb200204007 [17] 贾承造, 施央申, 郭令智.东秦岭板块构造[M].南京:南京大学出版社, 1988.1~130.JIA Cheng-zao, SHI Yang-shen, GUO Ling-zhi.Plate tectonics in the east of Qinling Mountain[M].Nanjing :Press of Nanjing University, 1988.1~130. [18] 孙勇, 卢欣样, 韩松, 等.北秦岭早古生代二郎坪蛇绿岩片的组成和地球化学[J].中国科学(D辑), 1996, 26 (增刊):49~55. http://www.cnki.com.cn/Article/CJFDTOTAL-JDXK1996S1007.htmSUN Yong, LU Xin-xiang, HAN Song, et al.Composition and geochemistry of Erlangping ophiolite in North Qinling in Early Paleozoic era[J].Science in China (series D), 1996, 26 (Supp.):49~55. http://www.cnki.com.cn/Article/CJFDTOTAL-JDXK1996S1007.htm [19] 张宗清, 张国伟, 刘敦一, 等.秦岭造山带蛇绿岩、花岗岩和碎屑沉积岩同位素年代学和地球化学[M].北京:地质出版社, 2006.1~348.ZHANG Zong-qing, ZHANG Guo-wei, LIU Dun-yi, et al.Isotopic chronology and geochemistry of ophiolites, granites and clastic sedimentary rocks in the Qinling orogenic belt[M].Beijing :Geological Publishing House, 2006.1~348. [20] 张旗, 周国庆.中国蛇绿岩[M].北京:科学出版社, 2001.ZHANG Qi, ZHOU Guo-qing.Ophiolites in China[M].Beijing :Science Press, 2001. [21] 王铭生, 武新强, 宋峰, 等.河南毛集-二郎坪断陷带主体构造格架的确立及意义[J].中国区域地质, 1999, 18 (1):23~27. http://d.old.wanfangdata.com.cn/Periodical/zgqydz199901004WANG Ming-sheng, WU Xin-qiang, SONG Feng, et al.The establishment of the main structural framework of the MaojiErlangping down faulted zone in Henan and its significance[J].Regional Geology of China, 1999, 18 (1):23~27. http://d.old.wanfangdata.com.cn/Periodical/zgqydz199901004 [22] Ratschbacher L, Hacker B R, Calvert A, et al.Tectonics of the Qinling (CentralChina):Tectonostratigraphy, geochronology, and deformation history[J].Tectonophysics, 2003, 366:1~53. doi: 10.1016/S0040-1951(03)00053-2 [23] 张国伟, 孟庆任, 赖绍聪.秦岭造山带结构构造[J].中国科学(B辑), 1995, 25 (9):994~1003. http://cdmd.cnki.com.cn/Article/CDMD-11941-2009176630.htmZHANG Guo-wei, MENG Qing-ren, LAI Shao-cong.Texture and structure of Qinling Orogen[J].Science in China (Series B), 1995, 25 (9):994~1003. http://cdmd.cnki.com.cn/Article/CDMD-11941-2009176630.htm [24] 卢欣祥.秦岭花岗岩大地构造图(1:1000000)[M].西安:西安地图出版社, 2000.LU Xin-xiang.Tectonic map of granites in Qinling (1:1000000)[M].Xi'an:Xi'an Map Press, 2000. [25] 席文祥, 巴光进, 亢进法.豫西卢氏县朱阳关组的建立[J].中国区域地质, 1994, 4:298~300. http://www.cnki.com.cn/Article/CJFDTOTAL-ZQYD404.002.htmXI Wen-xiang, BA Guang-jin, KANG Jin-fa.The establishment of the Zhuyangguan Formation[J].Regional Geology of China, 1994, 4:298~300. http://www.cnki.com.cn/Article/CJFDTOTAL-ZQYD404.002.htm [26] 周世全, 朱广彬, 冯祖杰.河南内乡夏馆-高丘盆地的夏馆组及其时代[J].资源调查与环境, 2003, 24 (1): 69~74. http://d.old.wanfangdata.com.cn/Periodical/hsdzykc200301011ZHOU Shi-quan, ZHU Guang-bin, FENG Zu-jie.Xiaguan Formation and its era of Xiaguan-Gaoqiu Basin in Neixiang County, Henan Province[J].Volcanology & M ineral Resources, 2003, 24 (1):69~74. http://d.old.wanfangdata.com.cn/Periodical/hsdzykc200301011 [27] 田伟, 魏春景.北秦岭造山带加里东期低A1-TTD系列:岩石特征、成因模拟及地质意义[J].中国科学(D辑), 2005, 35 (3):215~224.TIAN Wei, WEI Chun-jing.Petrological features, formation model and geological significance of Caledonian low Al-TTD series in north Qinling orogen[J].Science in China (Series D), 2005, 35 (3):215~224. [28] 高联达, 王宗起, 王涛, 等.河南西峡地区二郎坪群火神庙组中发现泥盆纪孢子化石[J].地质通报, 2006, 25 (11):1287~1294. doi: 10.3969/j.issn.1671-2552.2006.11.006GAO Lian-da, WANG Zong-qi, WANG Tao.Discovery of Devonian spores in the Huoshenmiao Formation of the Erlangping Group in the Xixia area, Henan, China[J].Geological Bullitin of China, 2006, 25 (11):1287~1294. doi: 10.3969/j.issn.1671-2552.2006.11.006 [29] 周汉文, 陈能松.豫西东秦岭造山带低压变质带的变质变形和变质反应[J].地球科学-中国地质大学学报, 1994, 19 (1):9~18. http://www.cqvip.com/Main/Detail.aspx?id=1308900ZHOU Han-wen, CHEN Neng-song.Metamorphism, deformation and metamorphic reactions of low-pressure metamorphic belt in East Qinling Orogenic Belt, western Henan[J].Earth Science-Journal of China University of Geosciences, 1994, 19 (1):9~18. http://www.cqvip.com/Main/Detail.aspx?id=1308900 [30] Massonne H, Szpurka Z.Thermodynamic properties of white micas on the basis of high-pressure experiments in the systems K2OMgO-Al2O3-SiO2-H2O and K2O-FeO-Al2O3-SiO2-H2O[J].Lithos, 1997, 41:229~250. doi: 10.1016/S0024-4937(97)82014-2 [31] 赵东林, 胡能高, 安三元.北秦岭二郎坪岩群40Ar/39Ar坪年龄特征及其地质意义[J].矿物学报, 1998, 18 (1): 101~104. http://www.cqvip.com/qk/95783X/199801/3014296.htmlZHAO Dong-lin, HU Neng-gao, AN San-yuan.40Ar/39Ar plateau age spectra of Erlangping Group, North Qinling and their geological implications[J].Acta M ineralogica Sinica, 1998, 18 (1):101~104. http://www.cqvip.com/qk/95783X/199801/3014296.html [32] Dodson M H.Closure temperature in cooling geochronological and petrological systems[J].Contributions to Mineralogy and Petrology, 1973, 40 (3):259~274. doi: 10.1007/BF00373790 [33] Mark Harrison T.Diffusion of 40Ar in hornblende[J].Contributions to Mineralogy and Petrology, 1981, 78 (3):324~331. doi: 10.1007-BF00398927/ [34] McDougall I, Harrison T M.Geochronology and thermochronology by the 40Ar/39Ar method[M].Oxford:Oxford University Press, 1999.1~269. [35] 胡圣标, 郝杰, 付明希, 等.秦岭-大别-苏鲁造山带白垩纪以来的抬升冷却史-低温年代学数据约束[J].岩石学报, 2005, 21 (4):1167~1173. http://d.old.wanfangdata.com.cn/Periodical/ysxb98200504015HU Sheng-biao, HAO Jie, FU Ming-xi, et al.Cenozoic denudation and cooling history of Qinling-Dabie-Sulu orogens:Apatite fission track thermochronology constraints[J].Acta Petrologica Sinica, 2005, 21 (4):1167~1173. http://d.old.wanfangdata.com.cn/Periodical/ysxb98200504015 [36] Zhang G W, Yu Z P, Sun Y, et al.The major suture zone of the Qinling orogenic belt[J].Southeast Asia Earth S cience, 1989, 3:63~76. doi: 10.1016/0743-9547(89)90010-X [37] Xue F, Lerch F, Kröner A.et al.Tectonic evolution of the East Qinling Mountains, China, in the Paleozoic:A review and a new tectonic model[J].Tectonophysics, 1996, 253:271~284. doi: 10.1016/0040-1951(95)00060-7 [38] 王作勋, 王宗起, 姜春发, 等.秦岭造山带显生宙构造迁移与陶湾群沉积变形[M].北京:地震出版社, 1995. 1~104.WANG Zuo-xun, WANG Zong-qi, JIANG Chun-fa, et al.Phanerozoic structural dislocation and Taowan Group deformation in Qinling Orogen[M].Beijing:Seismic Publishing House, 1995.1~104. [39] 姜春发.中央造山带几个重要地质问题及其研究进展(代序)[J].地质通报, 2002, 21 (8~9):453~455. http://d.old.wanfangdata.com.cn/Periodical/zgqydz200208001JIANG Chun-fa.Several important geological problems and their research review in Central Orogenic Belt[J].RegionalGeology of China, 2002, 21 (8~9):453~455. http://d.old.wanfangdata.com.cn/Periodical/zgqydz200208001 -
下载:
图(8) / 表(1)
计量
- 文章访问数: 214
- HTML全文浏览量: 77
- PDF下载量: 8
- 被引次数: 0
