U-Pb ages of zircon from metamorphic dolomite of the Wuliangshan Rock Group in Nanjian area, western Yunnan, and its tectonic significance
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摘要:
滇西南涧-云县一带广泛出露的无量山岩群是一套与三江特提斯造山带密切相关的中低变质沉积岩夹火山岩系,其形成时代、沉积充填序列及大地构造属性一直存在争议。出露于南涧县公郎乡一带的无量山岩群发育有厚数厘米的变质英安岩夹层。对变质英安岩进行LA-ICP-MS锆石U-Pb定年,分别获得428.7±8.7Ma的岩浆结晶年龄和338~387Ma、250.5±8.1Ma、146.0±6.0Ma的变质年龄。认为无量山岩群原始沉积岩形成于志留纪,在古特提斯洋俯冲过程中,经历古生代造弧而发生区域变质作用,在白垩纪受热事件影响而发生热变质作用;同时还获得2034±22Ma、1140±16Ma、731±15Ma及469~522Ma的单颗粒锆石年龄,这些年代峰值与整个扬子陆块西缘获得的前寒武纪、古生代构造热事件年龄及分布特征基本可以对比;记录了Columbia、Rodinia和Gondwana超大陆的形成与裂解过程。
Abstract:The Wuliangshan Rock Group, which is widely exposed in the Nanjian-Yunxian area of western Yunnan, is a set of low and medium metamorphic sedimentary rocks intercalated with volcanic rocks closely related to the Sanjiang Tethys orogenic belt. Its formation age, sedimentary filling sequence and tectonic attributes have been controversial. The Wuliangshan Rock Group, exposed in Gonglong County and Nanjian County, has a metamorphic ananite intercalation several centimeters thick. The zircon U-Pb LAICP-MS dating of the metamorphic andesite Sample was carried out, and the magmatic crystallization age of 428.7±8.7Ma and the metamorphic age of 338~387Ma, 250.5 ±8.1Ma and 146.0 ±6.0Ma were obtained respectively. It is considered that the original sedimentary rocks of the Wuliangshan Rock Group were formed in Silurian and experienced regional metamorphism in the Palaeozoic arc forming process during the Paleo-Tethys Ocean subduction and thermal metamorphism in the Cretaceous period due to thermal events. At the same time, the single grain ages of 2034±22Ma, 1140±16Ma, 731±15Ma and 469~522Ma were obtained, which can be compared with the Precambrian, Paleozoic tectonic caloric event ages and distribution characteristics obtained from the western margin of the Yangtze block. It underwent the formation and breakup of Columbia, Rodinia and Gondwana supercontinent.
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表 1 变质英安岩LA-ICP-MS锆石U-Th-Pb同位素测试数据
Table 1. LA-ICP-MS zircon U-Th-Pb analytical data of the metamorphic dolomite
测点号 含量/10-6 同位素比值 年龄/Ma 谐和度 Th/U 采用年龄/Ma Th U 207Pb/206Pb 1σ 207Pb/235U 1σ 206Pb/238U 1σ 207Pb/206Pb 1σ 207Pb/235U 1σ 206Pb/238U 1σ 1 401 481 0.051 0.007 0.167 0.019 0.024 0.001 243 28 157 17 156 5 99% 0.83 156 2 103 1511 0.048 0.005 0.146 0.014 0.022 0.001 100 23 138 12 142 4 96% 0.07 142 3 107 147 0.053 0.006 0.586 0.056 0.080 0.003 332 24 468 36 497 15 93% 0.73 497 4 257 464 0.054 0.004 0.533 0.039 0.072 0.002 372 18 433 26 445 9 97% 0.55 445 5 570 653 0.049 0.005 0.150 0.014 0.023 0.001 150 24 142 13 147 5 96% 0.87 147 6 454 610 0.049 0.008 0.139 0.018 0.022 0.001 167 34 132 16 139 5 95% 0.74 139 7 138 1524 0.053 0.004 0.290 0.022 0.041 0.001 339 19 258 17 257 5 99% 0.09 257 8 126 644 0.078 0.003 2.070 0.084 0.193 0.003 1146 82 1139 28 1140 16 99% 0.20 1140 91492270.2580.01014.4800.8430.4040.01632336327825521857375%0.65323310 233 1219 0.147 0.005 7.561 0.234 0.371 0.005 2317 54 2180 28 2034 22 93% 0.19 2034 115496930.0900.0070.7630.0590.0620.00114311557634389761%0.7938912 368 982 0.052 0.003 0.494 0.029 0.068 0.001 287 13 407 20 426 7 95% 0.37 426 13 396 541 0.049 0.007 0.151 0.017 0.023 0.001 165 29 143 15 148 4 96% 0.73 148 14 558 810 0.052 0.006 0.167 0.017 0.022 0.001 302 26 157 15 143 5 90% 0.69 143 15 228 283 0.058 0.008 0.335 0.044 0.042 0.002 528 50 294 34 266 10 90% 0.80 266 16 518 1680 0.060 0.005 0.446 0.033 0.054 0.001 611 16 375 23 338 8 89% 0.31 338 17 272 398 0.077 0.005 1.285 0.093 0.120 0.003 1111 13 839 41 731 15 86% 0.68 731 18 26.6 357 0.065 0.006 0.551 0.049 0.062 0.002 772 20 446 32 387 10 85% 0.07 387 192255620.1270.0063.5680.1560.2010.00320547715423511801873%0.40118020 363 135 0.059 0.008 0.661 0.085 0.084 0.003 554 29 515 52 522 16 98% 2.69 522 21 589 727 0.057 0.004 0.622 0.043 0.077 0.002 506 15 451 27 437 9 97% 0.81 437 22 140 634 0.055 0.005 0.496 0.039 0.066 0.002 409 19 409 26 409 9 99% 0.22 409 23 320 520 0.059 0.004 0.601 0.040 0.074 0.002 565 15 478 25 458 13 95% 0.62 458 24 675 1182 0.062 0.003 0.577 0.032 0.067 0.002 672 11 463 21 416 10 89% 0.57 416 25 31.5 161 0.056 0.008 0.468 0.073 0.067 0.004 456 32 390 50 418 25 92% 0.20 418 26 190 263 0.056 0.005 0.526 0.043 0.067 0.002 450 21 429 29 419 11 97% 0.72 419 27 161 291 0.057 0.005 0.528 0.042 0.067 0.002 500 18 431 28 419 9 97% 0.56 419 28 225 427 0.057 0.004 0.536 0.036 0.070 0.001 483 16 436 24 436 8 99% 0.53 436 29 288 531 0.057 0.003 0.595 0.032 0.076 0.001 476 12 474 21 469 7 99% 0.54 469 30 157 597 0.056 0.003 0.533 0.029 0.069 0.001 450 12 434 19 428 9 98% 0.26 428 31 362 595 0.051 0.004 0.275 0.021 0.039 0.001 256 20 246 17 247 6 99% 0.61 247 32 552 683 0.048 0.004 0.241 0.017 0.036 0.001 87 18 219 14 230 5 95% 0.81 230 33 943 830 0.051 0.003 0.277 0.019 0.039 0.001 232 16 248 15 246 5 99% 1.14 246 34 492 747 0.054 0.004 0.290 0.018 0.039 0.001 361 15 258 14 248 5 95% 0.66 248 注:删除线表示锆石年龄谐和度较低,年龄加权平均值计算中未使用该数据 -
[1] 侯泉林.滇西无量山地区的构造特征及变形和变质探讨[D].中国科学院地质研究所博士学位论文, 1991: 1-66.
http://d.g.wanfangdata.com.cn/Thesis_Y111683.aspx [2] 刘俊来, 宋志杰, 曹淑云, 等.印度-欧亚侧向碰撞带构造-岩浆演化的动力学背景与过程——以藏东三江地区构造演化为例[J].岩石学报, 2006, 22(4):775-786. http://d.old.wanfangdata.com.cn/Periodical/ysxb98200604002
[3] 侯泉林, 钟大赉, 郭谦谦.滇西无量山地区的构造变形和变质作用[J].地质科学, 2013, 48(2):354-361. doi: 10.3969/j.issn.0563-5020.2013.02.003
[4] 赵靖, 钟大赉, 王毅.滇西澜沧变质带变形系列与变形作用初步研究[J].地质科学, 1994, 29(4):366-369.
[5] 赵靖, 钟大赉, 王毅.滇西澜沧变质带变质作用和变形作用的关系[J].岩石学报, 1994, 10(1):27-29. doi: 10.3321/j.issn:1000-0569.1994.01.003
[6] 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
[7] Liu Y S, Gao S, Hu Z C, et al. Continental and oceaniccrust recycling-induced melt-peridotite interactions in the Trans-North China Orogen:U-Pb dating, Hf isotopes and trace elements in zircons of mantle xenoliths[J]. Journal of Petrology, 2010, 51(1/2):537-571.
[8] Liu Y S, Hu Z C, Gao S, et al. In situ analys-is of major and trace elements of anhydrous minerals by LA-ICP-MS without applying an internal standard[J]. Chemical Geology, 2008, 257(1/2):34-43.
[9] Liu Y S, Hu Z C, Zong K Q, et al. Reappraisement and refinement of zircon U-Pb isotope and trace element analyses by LA-ICP-MS[J]. Chinese Science Bulletin, 2010, 55(15):1535-1545. doi: 10.1007/s11434-010-3052-4
[10] Widenbeck M, Alle P, Corfu F, et al. Three natural zircon standards for U-Th-Pb, Lu-Hf trace element and REE analyses[J]. Geostandards and Geoanalytical Research, 1995, 19(1):1-23. doi: 10.1111/j.1751-908X.1995.tb00147.x
[11] Ludwig K R. Isoplot 3.00: A Geochronological toolkit for Microsoft excel[M]. Berkeley Geochronology Center Special Publication, 2003.
[12] 王海然, 赵红格, 乔建新, 等.锆石U-Pb同位素测年原理及应用[J].地质与资源, 2013, 22(3):229-242. doi: 10.3969/j.issn.1671-1947.2013.03.012
[13] 李再会, 林仕良, 丛峰, 等.滇西高黎贡山群变质岩的锆石年龄及其构造意义[J].岩石学报, 2012, 8(5):1529-1541. http://d.old.wanfangdata.com.cn/Periodical/ysxb98201205015
[14] Hoskin P W O, Schaltegger U. The composition of zircon and igneous and metamorphic petrogenesis[J]. Reviews in Mineralogy and Geochemistry, 2003, 53:27-62. doi: 10.2113/0530027
[15] 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. doi: 10.3321/j.issn:0023-074X.2004.16.002
[16] Hu Z, Gao S, Liu Y, et al. Signal enhancement in laser ablation ICP-MS by addition of nitrogen in the central channel gas[J]. Journal of Analytical Atomic Spectrometry, 2008, 23(8):1093-1101. doi: 10.1039/b804760j
[17] Pogers J J W, Santosh M. Configuration of Columbia, a Mesoproterozoic Supercontinent[J]. Gondwana Res., 2002, 5:5-22. doi: 10.1016/S1342-937X(05)70883-2
[18] Zhao G C, Cawood P A, Wilde S A, et al. A review of the global 2.1~1.8Ga orogens:Implications for a Pre-Rodinian super continent[J]. Earth-Sci. Rev., 2002, 59:125-162. doi: 10.1016/S0012-8252(02)00073-9
[19] Zhao G C, Sun M, Wilde S A, et al. A Paleo-Mesoproterozoic supercontinent:Assembly, growth and breakup[J]. Earth-Sci. Rev., 2004, 67:91-123. doi: 10.1016/j.earscirev.2004.02.003
[20] 翟明国, 从柏林, 乔广生, 等.中国滇西南造山带变质岩的SmNd和Rb-Sr同位素年代学[J].岩石学报, 1990, 4:1-11.
[21] 刘军平, 田素梅, 丛峰, 等.滇西澜沧江南段沙乐花岗岩的锆石U-Pb年龄、地球化学特征及其地质意义[J].沉积与特提斯地质, 2017, 37(4):59-70. http://www.wanfangdata.com.cn/details/detail.do?_type=perio&id=yxgdl201704005
[22] 刘军平, 胡绍斌, 李静, 等.滇西云县地区团梁子岩组变质岩锆石U-Pb年龄及其构造意义[J].地质通报, 2018, 37(11):2079-2086. http://dzhtb.cgs.cn/gbc/ch/reader/view_abstract.aspx?file_no=20181114&flag=1
[23] 毛晓长, 王立全, 李冰, 等.云县-景谷火山弧带大中河晚志留世火山岩的发现及其地质意义[J].岩石学报, 2015, 28(5):1517-1528. http://d.old.wanfangdata.com.cn/Periodical/ysxb98201205014
[24] 刘军平, 李静, 孙柏东, 等.滇中易门地区发现化石新物种[J].沉积与特提斯地质, 2018, 38(1):37-40. doi: 10.3969/j.issn.1009-3850.2018.01.004
[25] 刘军平, 曾文涛, 徐云飞, 等.滇中易门地区约1.85Ga凝灰岩的厘定及其地质意义[J].地质通报, 2018, 37(11):2055-2062. http://dzhtb.cgs.cn/gbc/ch/reader/view_abstract.aspx?file_no=20181111&flag=1
[26] 刘军平, 曾文涛, 徐云飞, 等.滇中峨山地区中元古界昆阳群黑山头组火山岩锆石U-Pb年龄及其地质意义[J].地质通报, 2018, 37(11):2063-2070. http://dzhtb.cgs.cn/gbc/ch/reader/view_abstract.aspx?file_no=20181112&flag=1
[27] 刘军平, 曾文涛, 孙柏东, 等.云南峨山地区东川群黑山组流纹质碎斑熔岩锆石U-Pb年龄及其地质意义[J].沉积与特提斯地质, 2018, 38(3):19-25. http://d.old.wanfangdata.com.cn/Periodical/yxgdl201803011
[28] 李静, 刘桂春, 刘军平, 等.滇中地区早前寒武纪地质研究进展[J].地质通报, 2018, 37(11):1957-1969. http://dzhtb.cgs.cn/gbc/ch/reader/view_abstract.aspx?file_no=20181101&flag=1
[29] 刘桂春, 李静, 胡绍斌, 等.滇中元江早元古代浊积岩特征及地质意义[J].地质通报, 2018, 37(11):2007-2014. http://dzhtb.cgs.cn/gbc/ch/reader/view_abstract.aspx?file_no=20181106&flag=1
[30] 陆松年, 杨春亮, 李怀坤, 等.华北古大陆与哥伦比亚超大陆[J].地学前缘, 2002, 9(9):226-233. http://d.old.wanfangdata.com.cn/Periodical/dxqy200204002
① 云南区测队. 1: 100万下关幅区域地质报告.1965.
② 云南省地质局. 1: 20万巍山幅区域地质报告.1976.
③ 云南省地质矿产局. 1: 20万保山幅区域地质报告. 1981.
④ 云南省地质调查院.《云南省区域地质志》(第二版, 修测). 2019.
⑤ 云南省地质调查院. 1: 25万凤庆县幅区域地质报告. 2007.
⑥ 云南省地质调查院. 1: 25万大理市幅区域地质报告. 2008.
⑦ 云南省地质调查院. 1: 25万景洪市幅区域地质报告. 2012.
⑧ 成都地质调查中心.云南省1: 50000 (诗礼、大河、犀牛街、老家库、哨街幅)区域地质调查报告. 2014.
⑨ 云南省地质调查院.云南省1: 50000(牛街、鼠街、兔街、大马街幅)区域地质调查报告. 2013.