The discovery of sedimentary intercalations in Emeishan basalt in the Zhaotong area, Northeastern Yunnan: the new evidence of episodic eruption
-
摘要:
首次在滇东北昭通地区峨眉山玄武岩中识别出3套沉积夹层，显示峨眉山玄武岩主喷发期内至少存在3次较长的喷发间歇期，以沉积夹层为亚旋回划分标志，将研究区峨眉山玄武岩划分为4个喷发亚旋回，沉积夹层的存在为峨眉山玄武岩幕式喷发提供了新的关键性证据。研究区峨眉山玄武岩第三亚旋回和第四亚旋回之间的沉积夹层沉积厚度大、沉积特征明显，本次工作选取其中的玄武质细砂岩进行了LA-ICP-MS测年，获得锆石U-Pb年龄为261.6 ± 0.6 Ma，代表了昭通地区峨眉山玄武岩主喷发期的时间，同时限定了沉积夹层的沉积时间下限。峨眉山玄武岩的喷发中心和火山机构展布可能受到区域上深大断裂的影响和控制，喷发形式为多期次多点位喷发，而沉积夹层发育于玄武岩多点喷发形成的小型山间凹陷汇水盆地。
Abstract:Three sets of sedimentary intercalations were systematically identified in Emeishan basalt in the Zhaotong area, Northeastern Yunnan for the first time, indicating that there were at least three long eruption intermissions during the main eruption period of Emeishan basalt.Taking the sedimentary intercalations as the subcycle division mark, the Emeishan basalt in the study area could be divided into four eruption subcycles.The existence of sedimentary intercalation provides a new key evidence for the episodic eruption of Emeishan basalt.The sedimentary intercalations between the third and fourth subcycles of Emeishan basalt in the study area have large sedimentary thickness and obvious sedimentary characteristics.In this work, the basaltic fine sandstone was selected for LA-ICP-MS dating, and the zircon U-Pb age was 261.6 ± 0.6 Ma.This age represents the time of the main eruption period of Emeishan basalt in the Zhaotong area, and defines the lower limit of the sedimentation time of the sedimentary intercalation.The eruption center and volcanic mechanism distribution of Emeishan basalt may be influenced and controlled by the deep faults in the region.The eruption form is multi-stage and multi-point eruption, while the sedimentary intercalations are developed in a small intermountain depression catchment basin formed by multi-point eruption of basalt.
-
Key words:
- U－Pb dating /
- sedimentary intercalation /
- Emeishan basalt /
- Zhaotong /
- geological survey engineering /
- Yunnan Province
-
-
表 1 PM027-2样品LA-ICP-MS锆石U-Th-Pb同位素分析结果
Table 1. The LA-ICP-MS zircon U-Th-Pb isotopic analysis results of PM027-2 sample
编号 元素含量/10-6 Th/U 同位素比值 年龄/Ma 谐和度
/%Pb Th U 207Pb/
206Pb1σ 207Pb/
235U1σ 206Pb/
238U1σ 207Pb/
206Pb1σ 207Pb/
235U1σ 206Pb/
238U1σ 208Pb/
232Th1σ PM027-2-1 5.6 126.1 97.7 1.2907 0.0509 0.0044 0.294 0.028 0.04132 0.00077 236 180 262 22 261 5 256 14 100 PM027-2-2 10.5 196.0 221.0 0.8869 0.0549 0.0037 0.312 0.024 0.04098 0.00078 408 139 276 19 259 5 275 16 107 PM027-2-3 12.6 217.0 231.8 0.9362 0.0514 0.0026 0.300 0.018 0.04238 0.00067 259 109 266 14 268 4 262 12 99 PM027-2-4 5.9 59.4 120.7 0.4921 0.0515 0.0035 0.295 0.022 0.04161 0.00077 1008 122 825 42 760 14 756 43 100 PM027-2-6 4.7 96.5 85.1 1.1340 0.0485 0.0049 0.277 0.028 0.04140 0.00095 124 183 248 22 262 6 249 15 95 PM027-2-7 3.4 46.8 65.9 0.7097 0.0534 0.0050 0.298 0.029 0.04134 0.00089 346 180 265 23 261 6 272 19 102 PM027-2-8 4.1 57.2 81.1 0.7053 0.0539 0.0046 0.295 0.025 0.04088 0.00088 367 153 262 20 258 5 259 16 102 PM027-2-9 8.8 94.4 190.7 0.4950 0.0552 0.0034 0.312 0.020 0.04150 0.00072 530 336 289 47 259 11 273 46 105 PM027-2-11 47.0 956.0 799.0 1.1965 0.0551 0.0018 0.324 0.014 0.04279 0.00051 416 75 285 11 270 3 280 11 106 PM027-2-12 12.5 276.1 214.3 1.2884 0.0534 0.0029 0.304 0.019 0.04146 0.00061 346 115 270 15 262 4 255 11 103 PM027-2-13 3.2 61.5 58.3 1.0549 0.0481 0.0063 0.264 0.035 0.04130 0.00120 104 234 238 28 261 7 242 18 91 PM027-2-14 7.1 146.0 119.5 1.2218 0.0498 0.0036 0.293 0.023 0.04264 0.00078 186 143 261 18 269 5 267 14 97 PM027-2-15 2.5 33.3 46.9 0.7100 0.0504 0.0068 0.279 0.038 0.04250 0.00120 213 251 250 30 268 7 283 26 93 PM027-2-17 3.8 65.2 69.3 0.9408 0.0506 0.0051 0.288 0.030 0.04188 0.00098 223 191 257 24 264 6 273 18 97 PM027-2-18 10.3 226.1 176.0 1.2847 0.0499 0.0031 0.284 0.019 0.04149 0.00071 190 121 254 15 262 4 260 12 97 PM027-2-19 7.2 179.2 114.1 1.5706 0.0520 0.0040 0.292 0.023 0.04126 0.00088 285 140 260 18 261 5 259 12 100 PM027-2-20 33.2 815.0 540.4 1.5081 0.0515 0.0020 0.297 0.014 0.04166 0.00053 515 162 289 22 263 5 252 17 100 PM027-2-23 4.5 99.6 78.1 1.2753 0.0510 0.0049 0.295 0.029 0.04196 0.00082 241 186 262 23 265 5 251 14 99 PM027-2-24 3.3 44.9 64.2 0.6994 0.0564 0.0057 0.320 0.033 0.04140 0.00110 468 183 282 25 262 7 250 20 108 PM027-2-25 7.8 111.6 145.5 0.7670 0.0540 0.0036 0.312 0.022 0.04192 0.00072 371 129 276 17 265 4 271 14 104 PM027-2-26 2.5 28.4 51.0 0.5569 0.0533 0.0064 0.291 0.034 0.04090 0.00100 342 218 259 27 258 6 265 24 100 PM027-2-27 8193.0 1396.0 1763.0 0.7918 0.1261 0.0022 5.988 0.210 0.34380 0.00420 2044 45 1974 31 1905 20 1873 66 107 PM027-2-28 17.0 234.3 353.7 0.6624 0.0540 0.0024 0.312 0.017 0.04170 0.00055 371 99 276 13 263 3 264 11 105 PM027-2-29 13.1 304.9 217.4 1.4025 0.0535 0.0028 0.309 0.018 0.04162 0.00069 350 102 273 14 263 4 264 12 104 PM027-2-30 19.4 111.7 236.1 0.4731 0.0566 0.0021 0.551 0.026 0.07000 0.00110 476 76 446 17 436 7 442 22 102 PM027-2-31 21.0 91.5 122.1 0.7494 0.0682 0.0025 1.301 0.060 0.13690 0.00190 875 72 846 26 827 11 820 35 102 PM027-2-32 2.9 39.8 58.7 0.6787 0.0486 0.0058 0.273 0.034 0.04124 0.00100 129 231 245 27 261 6 242 20 94 PM027-2-33 3.7 75.1 68.1 1.1028 0.0530 0.0052 0.302 0.031 0.04115 0.00093 329 190 268 24 260 6 253 15 103 PM027-2-34 8.1 127.9 153.7 0.8321 0.0512 0.0034 0.300 0.022 0.04146 0.00070 250 136 266 17 262 4 262 13 102 PM027-2-35 14.0 193.7 275.7 0.7026 0.0540 0.0025 0.307 0.016 0.04116 0.0006100 371 91 272 12 260 4 258 12 105 
下载: 导出CSV
-
[1] Chung S L, Jahn B M. Plume-lithosphere interaction in generation of the Emeishan flood basalts at the Permian-Triassic boundary[J]. Geology, 1995, 23(10): 889-892. doi: 10.1130/0091-7613(1995)023<0889:PLIIGO>2.3.CO;2
[2] Courtillot V, Jaupart C, Manighetti I, et al. On causal links between flood basalts and continental breakup[J]. Earth and Planetary Science Letters, 1999, 166(3): 177-195.
[3] 张招崇. 关于峨眉山大火成岩省一些重要问题的讨论[J]. 中国地质, 2009, 36(3): 634-646. doi: 10.3969/j.issn.1000-3657.2009.03.010
[4] 徐义刚, 何斌, 罗震宇, 等. 我国大火成岩省和地幔柱研究进展与展望[J]. 矿物岩石地球化学通报, 2013, 32(1): 25-39. doi: 10.3969/j.issn.1007-2802.2013.01.002
[5] 张云湘, 骆耀南, 杨崇喜, 等. 攀西裂谷[M]. 北京: 地质出版社, 1988.
[6] 陈文一, 刘家仁, 王中刚, 等. 贵州峨眉山玄武岩喷发期的岩相古地理研究[J]. 古地理学报, 2003, 5(1): 17-28. doi: 10.3969/j.issn.1671-1505.2003.01.002
[7] 何斌, 徐义刚, 肖龙, 等. 2006. 峨眉山地幔柱上升的沉积响应及其地质意义[J]. 地质论评, 2006, 52(1): 30-37. doi: 10.3321/j.issn:0371-5736.2006.01.005
[8] 李宏博, 张招崇, 吕林素, 等. 栖霞组和茅口组等厚图: 对峨眉山地幔柱成因模式的指示意义[J]. 岩石学报, 2011, 27(10): 2963-2974. https://www.cnki.com.cn/Article/CJFDTOTAL-YSXB201110016.htm
[9] 廖震文. 滇黔邻区与峨眉山玄武岩有关的铜矿、金矿地质特征对比[J]. 吉林大学学报(地球科学版), 2010, 40(4): 821-827. https://www.cnki.com.cn/Article/CJFDTOTAL-CCDZ201004012.htm
[10] 曾令高, 张均, 孙腾, 等. 峨眉山大火成岩省烂纸厂铁矿床地质特征、成因及其找矿勘查启示[J]. 吉林大学学报(地球科学版), 2016, 46(2): 412-424. https://www.cnki.com.cn/Article/CJFDTOTAL-CCDZ201602010.htm
[11] Gong D X, Hui B, Dai Z M, et al. A new type of REE deposit found in clay rock at the top of the Permian Emeishan basalt in the Yunnan-Guizhou area[J]. Acta Geologica Sinica, 2020, 94(1): 204-205. doi: 10.1111/1755-6724.14508
[12] 刘殿蕊. 云南宣威地区峨眉山玄武岩风化壳中发现铌、稀土矿[J]. 中国地质, 2020, 47(2): 540-541. https://www.cnki.com.cn/Article/CJFDTOTAL-DIZI202002021.htm
[13] 张兵强, 赵富远, 杨清毫, 等. 贵州省盘县架底金矿床成矿地质条件及找矿方向[J]. 吉林大学学报(地球科学版), 2022, 52(1): 94-108. https://www.cnki.com.cn/Article/CJFDTOTAL-CCDZ202201007.htm
[14] 陈军, 徐义刚. 二叠纪大火成岩省的环境与生物效应: 进展与前瞻[J]. 矿物岩石地球化学通报, 2017, 36(3): 374-393. doi: 10.3969/j.issn.1007-2802.2017.03.002
[15] 王向东. 晚二叠世—早三叠世火山喷发强度、时限及其与生物绝灭和后期复苏的关系[D]. 中国地质大学(武汉)博士学位论文, 2019.
[16] 朱江, 张招崇, 侯通, 等. 贵州盘县峨眉山玄武岩系顶部凝灰岩LA-ICP-MS锆石U-Pb年龄: 对峨眉山大火成岩省与生物大规模灭绝关系的约束[J]. 岩石学报, 2011, 27(9): 2743-2751. https://www.cnki.com.cn/Article/CJFDTOTAL-YSXB201109023.htm
[17] 李香君, 顾战宇, 雍自权, 等. 川西Ys1井峨眉山玄武岩岩相旋回及储层特征[J]. 矿物岩石, 2020, 40(1): 100-112. https://www.cnki.com.cn/Article/CJFDTOTAL-KWYS202001011.htm
[18] 徐涛, 张忠杰, 刘宝峰, 等. 峨眉山大火成岩省地壳速度结构与古地幔柱活动遗迹: 来自丽江-清镇宽角地震资料的约束[J]. 中国科学(D辑), 2015, 45(5): 561-576. https://www.cnki.com.cn/Article/CJFDTOTAL-JDXK201505002.htm
[19] 徐义刚, 何斌, 罗震宇, 等. 我国大火成岩省和地幔柱研究进展与展望[J]. 矿物岩石地球化学通报, 2013, (1): 25-39. https://www.cnki.com.cn/Article/CJFDTOTAL-KYDH201301003.htm
[20] Zhong Y T, He B, Mundil R, et al. CA-TIMS zircon U-Pb dating of felsic ignimbrite from the Binchuan section: implications for the termination age of Emeishan large igneous province[J]. Lithos, 2014, 204: 14-19.
[21] 张宏辉, 袁永盛, 余杨忠, 等. 扬子板块西缘中生代—新生代碰撞造山事件的记录: 来自峨眉山玄武岩的锆石U-Pb同位素证据[J]. 现代地质, 2021, 35(5): 1155-1177. https://www.cnki.com.cn/Article/CJFDTOTAL-XDDZ202105001.htm
[22] Thompson J, Meffre S, Danyushevsky L. Impact of air, laser pulse width and fluence on U-Pb dating of zircons by LA-ICPMS[J]. Journal of Analytical Atomic Spectrometry, 2018, 33: 221-230.
[23] Paton C, Woodhead J D, Hellstrom J C, et al. Improved laser ablation U-Pb zircon geochronology through robust downhole fractionation correction[J]. Geochemistry Geophysics Geosystems, 2010, 11: Q0AA06.
[24] Sláma J, Kosler J, Condon D J, et al. Plesovice zircon--A new natural reference material for U-Pb and Hf isotopic microanalysis[J]. Chemical Geology, 2008, 249: 1-35.
[25] Shellnutt J G, Zhou M F, Yan D P, et al. Longevity of the Permian Emeishan mantle plume(SW China): 1 Ma, 8 Ma or 18 Ma?[J]. Geological Magzine, 2008, 145(3): 373-388. http://kns.cnki.net/KCMS/detail/detail.aspx?dbcode=CJFD&filename=DZXW200804009
[26] Xu Y G, Luo Z Y, Huang X L, et al. Zircon U-Pb and Hf isotope constraints on crustal melting associated with the Emeishan mantle plume[J]. Geochimica et Cosmochimica Acta, 2008, 72: 3084-3104.
[27] 骆文娟, 张招崇, 侯通, 等. 攀西茨达复式岩体年代学和地球化学: 对峨眉山地幔柱活动时间的约束[J]. 岩石学报, 2011, 27(10): 2947-2962. https://www.cnki.com.cn/Article/CJFDTOTAL-YSXB201110015.htm
[28] Ali J R, Lo C H, Thompson G M, et al. Emeishan Basalt Ar-Ar overprint ages define several tectonic events that affected the western Yangtze Platform in the Mesozoic and Cenozoic[J]. Journal of Asian Earth Science, 2004, 23: 163-178.
[29] Boven A, Pasteels P, Punzalan L E, et al. 40Ar/39Ar geochronological constraints on the age and evolution of the Permo-Triassic Emeishan Volcanic Province, Southwest China[J]. Journal of Asian Earth Science, 2002, 20: 157-175.
[30] 李宏博. 峨眉山大火成岩省地幔柱动力学: 基性岩墙群、地球化学及沉积地层学证据[D]. 中国地质大学(北京)博士学位论文, 2012.
[31] 范蔚茗, 王岳军, 彭头平, 等. 桂西晚古生代玄武岩Ar-Ar和U-Pb年代学及其对峨眉山玄武岩省喷发时代的约束[J]. 科学通报, 2004, 49: 1892-1900. https://www.cnki.com.cn/Article/CJFDTOTAL-KXTB200418013.htm
[32] Lo C H, Chung S L, Lee T Y, et al. Age of the Emeishan flood magmatism and relations to Permian-Triassic boundary events[J]. Earth and Planetary Science Letters, 2002, 198: 449-458.
[33] 祝明金, 田亚洲, 聂爱国, 等. 黔南基性岩墙岩石地球化学、SHRIMP锆石U-Pb年代学及地质意义[J]. 地球科学, 2018, 43(4): 1333-1349. https://www.cnki.com.cn/Article/CJFDTOTAL-DQKX201804026.htm
[34] Shellnutt J G, Denyszyn S W, Mundil R. Precise age determination of mafic and felsic intrusive rocks from the Permian Emeishan large igneous province(SW China)[J]. Gondwana Research, 2012, 22(1): 118-126.
[35] Zhong Y T, He B, Mundil R, et al. CA-TIMS zircon U-Pb dating of felsic ignimbrite from the Binchuan section: implications for the termination age of Emeishan large igneous province[J]. Lithos, 2014, 204: 14-19.
[36] Yang J, Cawood P A, Du Y, et al. Early Wuchiapingian cooling linked to Emeishan basaltic weathering?[J]. Earth and Planetary Science Letters, 2018, 492: 102-111.
[37] 何斌, 徐义刚, 王雅玫, 等. 用沉积记录来估计峨眉山玄武岩喷发前的地壳抬升幅度[J]. 大地构造与成矿学, 2005, 29(3): 316-320. https://www.cnki.com.cn/Article/CJFDTOTAL-DGYK200503004.htm
[38] 吴鹏, 刘少峰, 窦国兴. 滇东地区峨眉山地幔柱活动的沉积响应[J]. 岩石学报, 2014, 30(6): 1793-1803. https://www.cnki.com.cn/Article/CJFDTOTAL-YSXB201406020.htm
[39] 邱寻欢. 云南寻甸地区峨眉山玄武岩磁组构研究及其地质意义[D]. 东华理工大学硕士学位论文, 2019.
① 王自廉, 马忠义, 符史标, 等. 昭通幅G-48-2 1/20万区域地质调查报告. 昆明: 云南省地质局区域地质调查队, 1978.
-
图(7)
表(1)
计量
- 文章访问数: 1485
- PDF下载数: 20
- 施引文献: 0