Depositional Environments and Tectonic Background of the Early Devonian Cherts of Southern Ailaoshan Tectonic Belt
-
摘要:
金沙江–哀牢山构造带在晚古生代发育的是古特提斯支洋还是弧后盆地尚存在争论，笔者对哀牢山构造带南段下泥盆统硅质岩开展岩相学、岩石地球化学等分析，以期为该地区构造演化提供新的证据。硅质岩地球化学特征显示出其为生物成因，SiO2与Al2O3、SiO2与TiO2具明显负相关性，说明硅质不是来自陆源物质，具Ce负异常，Ce/Ce*值为0.73～0.76，平均值为0.75，接近大洋盆地硅质岩特征；(La/Ce)N值为1.31～1.49，平均为1.38，接近开阔洋盆硅质岩特征。综合分析认为，硅质岩形成于边缘海向开阔大洋转换的环境，暗示金沙江–哀牢山构造带在晚古生代发育的是古特提斯支洋，而非弧后盆地。
Abstract:There is still a debate about whether the Jinshajiang Ailaoshan tectonic belt developed in the Late Paleozoic was a Paleo Tethyan Ocean or a backarc basin. This paper conducts petrographic and geochemical analyses of the Lower Devonian siliceous rocks in the southern section of the Ailaoshan tectonic belt in order to provide new evidence for the tectonic evolution of the area. The geochemical characteristics of siliceous rocks show that they are biogenic, with a significant negative correlation between SiO2 and Al2O3, and SiO2 and TiO2, indicating that siliceous rocks do not come from terrestrial sources and have a negative Ce anomaly. The Ce/Ce * value is 0.73 to 0.76, with an average value of 0.75, which is close to the characteristics of siliceous rocks in ocean basins; The LaN/CeN value ranges from 1.31 to 1.49, with an average of 1.38, which is close to the characteristics of siliceous rocks in open ocean basins. Based on comprehensive analysis, it is believed that the siliceous rocks were formed in a transitional environment from marginal seas to open oceans, suggesting that the Jinshajiang Ailaoshan tectonic belt developed in the Late Paleozoic in the Paleo Tethyan Ocean rather than in a backarc basin.
-
-
图 5 下泥盆统罗红组硅质岩类Al-Fe-Mn判别图解图（据Adachi M et al., 1986）
Figure 5.
图 6 Fe2O3/TiO2-Al2O3/（Al2O3+Fe2O3）（a）及LaN/CeN-Al2O3/（Al2O3+Fe2O3）（b）图解（据Murray, 1994）
Figure 6.
图 8 下泥盆统罗红组硅质岩北美页岩标准化模式图（据Taylor et al., 1985）
Figure 8.
图 9 哀牢山断裂两侧下泥盆统地层柱状图（东侧地层据云南省地质矿产局，1990；西侧为实测）
Figure 9.
表 1 下泥盆统罗红组硅质岩主量元素（%）分析数据
Table 1. Major （%） compositions of Silicous rock from Lower Devonian Luohong Formation
样号 D1-b1 D1-b2 D1-b3 D1-b4 D1-b5 D1-b6 SiO2 92.6 95.8 95.9 95.7 95.6 95.8 Al2O3 3.12 1.58 1.68 1.62 1.66 1.6 Fe2O3 1.88 1.14 1.04 1.17 1.22 1.35 FeO 0.13 0.19 0.14 0.31 0.89 0.30 P2O5 0.09 0.16 0.02 0.07 0.11 0.03 K2O 0.71 0.35 0.38 0.36 0.35 0.37 Na2O 0.07 0.04 0.02 0.03 0.02 0.03 MgO 0.12 0.07 0.07 0.08 0.06 0.06 CaO 0.04 0.02 ＜0.01 0.02 0.01 0.02 TiO2 0.11 0.05 0.05 0.06 0.04 0.05 MnO − − − − 0.01 − LoI 0.21 1.14 0.28 0.41 1.02 0.44 总量 98.95 100.35 99.44 99.52 100.1 99.75 
下载: 导出CSV
表 2 下泥盆统罗红组硅质岩稀土元素丰度（10−6）及主要参数
Table 2. REE analyses of Silicous rock Lower Devonian Luohong Formation (10−6)
样号 D1-b1 D1-b2 D1-b3 D1-b4 D1-b5 D1-b6 La 7.9 6.9 4.5 5.6 6.2 6.4 Ce 12.9 9.9 7.1 8.9 9.4 9.1 Pr 1.81 1.26 1.02 1.11 1.2 1.18 Nd 7.0 4.5 3.9 4.1 4.4 4.5 Sm 1.48 0.88 0.9 0.93 1.12 1.21 Eu 0.35 0.21 0.22 0.23 0.25 0.23 Gd 1.72 1.02 0.97 0.99 1.12 1.24 Tb 0.31 0.18 0.21 0.2 0.19 0.21 Dy 1.57 0.81 1.02 1.1 1.06 0.97 Ho 0.37 0.17 0.22 0.19 0.18 0.22 Er 1.02 0.51 0.58 0.5 0.54 0.65 Tm 0.15 0.08 0.08 0.09 0.11 0.1 Yb 0.94 0.54 0.5 0.61 0.72 0.71 Lu 0.14 0.08 0.07 0.08 0.09 0.1 ΣREE 37.66 27.04 21.29 24.63 26.58 26.82 LREE/HREE 5.05 6.98 4.83 5.55 5.63 5.39 LaN/YbN 0.79 1.20 0.85 0.87 0.81 0.85 Ce/Ce* 0.76 0.73 0.74 0.75 0.76 0.75 （La/Ce）N 1.31 1.49 1.36 1.34 1.41 1.38
下载: 导出CSV
-
[1] 方维萱, 胡瑞忠, 谢桂青, 等. 云南哀牢山地区构造岩石地层单元及其构造演化[J]. 大地构造与成矿学, 2002, 26（1）: 28−36.
FANG Weixuan, HU Ruizhong, XIE Guiqing, et al. Tectonolithostratigraphic units of the ailaoshan area in Yunnan, China and their implications of tectonic evolution[J]. Geotecttonica et Metallogenia, 2002, 26(1): 28−36.
[2] 黄虎, 杜元生, 杨江海, 等. 水城-紫云-南丹裂陷盆地晚古生代硅质沉积物地球化学特征及其地质意义[J]. 地质学报, 2012, 86（12）: 1994−2010. doi: 10.3969/j.issn.0001-5717.2012.12.010
HUANG Hu, DU Yuansheng, YANG Jianhai, et al. Geochemical features of siliceous sediments of the Shuicheng-Ziyun-Nandan rift basin in the Late Paleozoic and their tectonic implication[J]. Acta Geologica Sinica, 2012, 86(12): 1994−2010. doi: 10.3969/j.issn.0001-5717.2012.12.010
[3] 简平, 汪啸风, 何龙清, 等. 云南新平县双沟蛇绿岩U-Pb年代学初步研究[J]. 岩石学报, 1998, 14（2）: 207−211. doi: 10.3321/j.issn:1000-0569.1998.02.008
JIAN Ping, WANG Xiaofeng, HE Longqing, et al. A preliminary study U-Pb geochronology of the Shuang Gou ophiolite in Xinping County, Yunnan[J]. Acta Petrologica Sinica, 1998, 14(2): 207−211. doi: 10.3321/j.issn:1000-0569.1998.02.008
[4] 刘兵兵, 碰头平, 范蔚茗, 等. 哀牢山构造带两侧上志留—下泥盆统碎屑锆石年代学: 物源及其构造意义[J]. 大地构造与成矿学, 2017, 3（14）: 1−19.
LIU Bingbing, PENG Touping, FAN Weiming, et al. Geochronology of Detrital Zircon from the Upper Silurian‒ LowerDevonian Sedimentary Rocks at both Sides of the Ailaoshan TectonicZone: Provenance and Geological Significance[J]. Geotectonica et Metallogenia, 2017, 3(14): 1−19.
[5] 刘翠, 邓晋福, 刘俊来, 等. 哀牢山构造岩浆带晚二叠世—早三叠世火山岩特征及其构造环境[J]. 岩石学报, 2011, 27（12）: 3599−3602.
LIU Cui, DENG Jinfu, LIU Junlai, et al. Characteristics of volcanic rocks from Late Permian to Early Traissic in Ailaoshan tectono-magmatic belt and implications for tectonic settings[J]. Acta Petrologica Sinica, 2011, 27(12): 3599−3602.
[6] 刘汇川. 云南哀牢山构造带晚古生代至早中生代岩浆岩成因及构造演化[D]. 广州: 中国科学院广州地球化学研究所博士学位论文, 2014, 1-195.
LIU Huichuan. Petrogenesis of Late Paleozoic to early Mesozoic magmatic rocks in the Ailaoshan area (SW Yunnan): implications for the evolution of the Paleo-Tethys [D]. Guangzhou: The degree of Doctor of Science of Guangzhou Insititute of Geochemistry, Chinese Academy of Sciences, 2014, 1-195.
[7] 邱振, 王清晨, 严德天. 广西来宾蓬莱滩剖面中上二叠统硅质岩的地球化学特征及沉积背景[J]. 岩石学报, 2011a, 27（10）: 3141−3155.
QIU Zhen, WANG Qingchen, YAN Detian. Geochemistry and sedimentary background of the Middle-Upper Permian cherts in the Penglaitan section, Laibin, Guangxi Probince[J]. Acta Petrologica Sinica, 2011a, 27(10): 3141−3155.
[8] 邱振, 王清晨. 广西来宾中上二叠统硅质岩海底热液成因的地球化学证据[J]. 中国科学: 地球科学, 2011b, 41(5): 725-737.
QIU Zhen, WANG Qingchen. Geochemical evidence for submarine hydrothermal origin of the Middle-Upper Permian chert in Laibin of Guangxi, China [J]. Science in China: Series D Earth Sciences, 2010b, 41(5): 725-737.
[9] 孙崇波, 李忠权, 王道永. 等. 哀牢山造山带南段扭只二长花岗斑岩地球化学特征及其锆石U-Pb年代学研究[J]. 中国地质, 2016, 43（1）: 111−119.
SUN Chongbo, LI Zhongquan, WANG Daoyong, et al. Petrogeochemistry and zircon U-Pb chronology of the Niuzhi monzoniticporphyry in southern segment ofAilao Mountain tectonic belt[J]. Geologyin China, 2016, 43(1): 111−119.
[10] 孙崇波, 李忠权, 王道永. 等. 云南哀牢山构造带仰宗流纹斑岩锆石U-Pb年龄, 地球化学特征及构造意义[J]. 地质通报, 2017, 36（2-3）: 190−198.
SUN Chongbo, LI Zhongquan, WANG Daoyong, et al. Petrogeochemistry and zircon U-Pb chronology of the Yangzong rhyolite porphyry of Ailaoshan tectonic belt[J]. Geological Bulletin of China, 2017, 36(2-3): 190−198.
[11] 孙崇波, 李忠权, 陈晓东. 等. 哀牢山构造带南段风别山霏细斑岩地球化学特征及其锆石U-Pb年代学研究[J]. 地质论评, 2018, 64（5）: 1251−1262.
SUN Chongbo, LI Zhongquan, CHEN Xiaodong, et al. Petrogeochemistry and zircon U-Pb chronology of the Fengbieshan felsophyre in southern section of Ailaoshan tectonic belt[J]. Geological Review, 2018, 64(5): 1251−1262.
[12] 孙崇波, 李忠权, 王道永. 等. 哀牢山构造带南段马玉花岗闪长岩地球化学特征及其锆石U-Pb年龄[J]. 地质通报, 2019, 38（2-3）: 223−230.
SUN Chongbo, LI Zhongquan, WANG Daoyong, et al. Petrogeochemistry and zircon U-Pb age of the Mayu granodiorite in the southern section of Ailaoshan tectonic belt[J]. Geological Bulletin of China, 2019, 38(2-3): 223−230.
[13] 魏启荣, 沈上越. 哀牢山北段老王寨—浪泥塘一带蛇绿岩的形成环境[J]. 特提斯地质, 1995, 19: 57−70.
WEI Qirong, SHEN Shangyue. Depositional Environments of ophiolite in the Laowangzhai-Langnitang area in the northern part of Ailaoshan[J]. Tethyan Geology, 1995, 19: 57−70.
[14] 魏启荣, 沈上越, 莫宣学. 哀牢山硅质岩特征及其意义[J]. 地质科技情报, 1998, 17（2）: 29−34.
WEI Qirong, SHEN Shangyue, MO Xuanxue. Characteristics and Significance of slicolites in Ailaoshan area[J]. Geological Science and Technology Information, 1998, 17(2): 29−34.
[15] 杨振宇, 沈渭洲, 郑连弟. 广西来宾蓬莱滩二叠纪瓜德鲁普统—乐平统界限剖面元素和同位素地球化学研究及地质意义[J]. 地质学报, 2009, 83（1）: 1−15. doi: 10.3321/j.issn:0001-5717.2009.01.001
YANG Zhenyu, SHEN Weizhou, ZHENG Liandi. Element and isotopic geochemistry of Guadalupian-Lopingian boundary profile at the Penglaitan section of Laibin, Guangxi Province, and its geological implications[J]. Acta Geological Sinica, 2009, 83(1): 1−15. doi: 10.3321/j.issn:0001-5717.2009.01.001
[16] 云南省地质矿产局. 云南省区域地质志[M]. 北京: 地质出版社, 1990.
YUNNAN Bureau of Geology and Mineral Resurces. Regional Geological Records of Yunnan Province[M]. Beijing: Geology Press, 1990.
[17] 钟大赉. 滇川西部古特提斯造山带[M]. 北京: 科学出版社, 1998.
ZHONG Dalai. The paleo Tethyan orogenic belt in western Yunnan and Sichuan [M]. Beijing: Science Press, 1998.
[18] Adachi M, Yamamoto K, Sugisaki R. Hydrothermal chert and associated siliceous rocks from the Northern Pacific: Their geological significance as indication of ocean ridge activity[J]. Sedimentary Geology, 1986, 47(1-2): 125−148. doi: 10.1016/0037-0738(86)90075-8
[19] Bau M, Koschinsky A, Dulski P, et al. Comparison of the partitioning behaviours of yttrium, rare erth elements, and titanium between hydrogenetic marine ferromanganese crusts and seawater[J]. Geochimica et Cosmochimica Acta, 1996, 60(10): 1709−1725. doi: 10.1016/0016-7037(96)00063-4
[20] Chakrabarti R, Knoll A H, Jacobsen S B, et al. Si isotope variability in Proterozoic cherts[J]. Geochimica et Cosmochimica Acta, 2012, 91: 187−201. doi: 10.1016/j.gca.2012.05.025
[21] Chen D Z, Qing H R, Yan X, et al. Hydrothermal venting and basin evolution (Devonian, South China): constraints from rare earth element geochemistry of the chert[J]. Sedimentary Geology, 2006, 183(3-4): 203−216. doi: 10.1016/j.sedgeo.2005.09.020
[22] Chun Kit Lai, Sebastien Meffre, Anthony J C, et al. The central Ailaoshan ophiolite and modern analogs[J]. Gondwana Research: International Geoscience Journal, 2014, 26(1): 75−88.
[23] Elderfield H G, Greaves M J. The rare earth elements in seawater[J]. Nature, 1982, 296: 214−219. doi: 10.1038/296214a0
[24] Fan H F, Wen H J, Zhu X K, et al. Hydrothermal activity during Ediacaran-Cambrian transition: Silicon isotopic evidence[J]. Precambrian Research, 2013, 224: 23−35. doi: 10.1016/j.precamres.2012.09.004
[25] Fan W M, Wang Y J, Zhang F F, et al. Permian arc-back-arc basin development along the Ailaoshan tectoniczone: Ceochemical, isotopic and geochronol evidence from the Mojiang volcanic rocks, Southwest china[J]. Lithos, 2010, 119(3-4): 553−568. doi: 10.1016/j.lithos.2010.08.010
[26] Fleet A J. Hydrothermal and hydrogenous ferro-manganese deposits: Do they from a continuum? The rare earth element evidence. In: Rona P A, Bostrom K, Laubier L, Smith K L, eds. Hydrothermal Process at Seafloot Spreding Centers [J]. New York: Plenum Press, 1983, 535-555.
[27] Girty G H, Ridge D L, Knaack C, et al. Provenance and depoditional setting of Paleozoic chert and argillite, Sierra Nevada, California[J]. Journal of Sedimentary Research, 1996, 66(1): 107−118.
[28] Hara H, Kurihar T, Kurod J, et al. Geological and geochemical aspects of a Devonian siliceous succession in Northern Thailand: Implications for the opening of the Paleo-Tethys[J]. Palaeogeography, Palaeoclimatology, Palaeoecology, 2010, 297(2): 432−464.
[29] Huang Hu, Du Yuansheng, Huang Zhiqiang, et al. Depositional chemistry of chert during Late Paleozoic from western Guangxi and its implication for the tectonic evolution of the Youjiang Basin[J]. Science China: Earth Sciences, 2013, 43(2): 304−316.
[30] Jian P, Liu D Y, Kröner A, et al. Devonian to Permian platetectonic cycle of the Paleo-Tethys Orogen in southwest China (I): Geochemistry of ophiolites, arc/back-arcassemblages and within-plate igneous rocks[J]. Lithos, 2009a, 113: 748−766. doi: 10.1016/j.lithos.2009.04.004
[31] Jian P, Liu D Y, Kröner A, et al. Devonian to Permian platetectonic cycle of the Paleo-Tethys Orogen in southwestChina (II): Insights from zircon ages of ophiolites, arc/back-arc assemblages and within-plate igneousrocks and generation of the Emeishan CFB province[J]. Lithos, 2009b, 113: 767−784. doi: 10.1016/j.lithos.2009.04.006
[32] Jones J H, Hart S R. Extreme Incompatibility of Pb during the Crystallization of Magmatic Iron-Meteorites[J]. Meteoritics, 1994, 19(4): 248−248.
[33] Lewis K H, Garwood R J, Brasier M D, et al. Carbonaceous microstructures from sedimentary laminated chert within the 3.46 Ga Apex Basalt, Chinaman Creek locality, Pilbara, Western Australia[J]. Precambrian Research, 2016, 278: 161−178. doi: 10.1016/j.precamres.2016.03.013
[34] Metcalfe I. Palaeozoic and Mesozoic tectonicevolution and palaeogeography of East Asian crustalfragments: The Korean Peninsula in context[J]. Gondwana Research, 2006, 9: 24−46.
[35] Metcalfe I. Gondwana dispersion and Asian accretion: Tectonic and palaeogeographic evolution of easternTethys[J]. Journal of Asian Earth Sciences, 2013, 66: 1−33. doi: 10.1016/j.jseaes.2012.12.020
[36] Miroshnichenko N V, Perevoznikova Y V. The Intermetallic Compound Ni3Au and Gold-Nickel Solid Solutins in Metalliferous Sediments of the Triassic Chert Formation in Sikhote-Alin in the Far East[J]. Russian Journal of Pacific Geology, 2010, 4(1): 56−62. doi: 10.1134/S1819714010010045
[37] Molnar P and Tapponnier P. Cenozoic tectonics ofAsia: Effects of a continental collision [J]. Science, 189(4201): 1975, 419-426.
[38] Murray R W. Chemical criteria to identify the depoditionalenvironment of chert: general principles and application[J]. Sediment Geology, 1994, 90: 213−232. doi: 10.1016/0037-0738(94)90039-6
[39] Murray R W, Buchholtz T, Brink M R, et al. Rare earth elements as indicators of different marine depos-itional environments in chert and shale[J]. Geology, 1990, 18: 268−271.
[40] Murray R W, Buchholtz T, Brink M R, et al. Rare earth, major, and trace elements in chert from Franciscan Complex and Monterey Group: Assessing REE sources to fine-grained marine sediments[J]. Geochimica et Cosmochimica Acta, 1991, 55(7): 1875−1895. doi: 10.1016/0016-7037(91)90030-9
[41] Murray R W, Buchholtz Ten Brink M R, Gerlach D C, et al. Rare earth, major, and trace element composition of Monterey and DSDP chert and associated host sediment: Assessing the influence of chemical fractionation during diagenesis[J]. Geochimica et Cosmochimica Acta, 1992, 56(7): 2657−2671. doi: 10.1016/0016-7037(92)90351-I
[42] Pan G T, Wang L Q, Li R S, et al. Tectonic evolution ofthe Qinghai‒ T ibet Plateau[J]. Journal of Asian Earth Sciences, 2012, 53: 3−14. doi: 10.1016/j.jseaes.2011.12.018
[43] Schärer U, Tapponnier P, Lacassin R, et al. Intraplate tectonics in Asia: Aprecise age for large-scale Miocene movement alongthe Ailao Shan ‒ Red River shear zone[J]. China Earth and Planetary Science Letters, 1990, 97(1-2): 65−77. doi: 10.1016/0012-821X(90)90099-J
[44] Tapponnier P, Lacassin R, Leloup P H, et al. The Ailaoshan/Red River metamorphic belt: Tertiary left-lateral shear between Indochina and South China[J]. Nature, 1990, 343(6257): 431−437. doi: 10.1038/343431a0
[45] Taylor S R, McLennan S M. The Continental Crust, Its Composition and Evolution: an Examination of the Geochemical Record Preserved in Sedimentary Rocks [M]. Oxford: Blackwell Scientific Publications, 1985, 1−312.
[46] Thassanapak H, Udchachon M, Chonglakmani C, et al. Geochemistry of Middle Triassic radiolarian cherts from northern Thailand: Imlication for depositional environment[J]. Journal of Earth Science, 2011, 22(6): 688−703. doi: 10.1007/s12583-011-0220-7
[47] Thurston P C, Kamber B S, Whitehouse M. Archean cherts in banded iron formation insight into Neoarchean Ocean chemistry and depositional prscesses[J]. Precambrian Research, 2012, 214−215: 227−257. doi: 10.1016/j.precamres.2012.04.004
[48] Wang Q F, Deng J, Li C S, et al. The boundary between the Simao and Yangtze blocksnd their locations in Gondwana and Rodinia: Constraintsfrom detrital and inherited zircons[J]. Gondwana Research, 2014, 26: 438−448.
[49] Xia X P, Nie X S, Lai C K, et al. Where was the Ailaoshan Ocean and when did it open: A perspective based on detrital zircon U-Pb ageand Hf isotope evidence[J]. Gondwana Research, 2016, 36: 488−502. doi: 10.1016/j.gr.2015.08.006
[50] Xu J F, Castillo P R. Geochemical and Nd-Pb isotopic characteristics of theTethyan asthenosphere: implications for the origin of the Indian Ocean mantle domain[J]. Tectonophysics, 2004, 393(1−4): 9−27. doi: 10.1016/j.tecto.2004.07.028
[51] Yin Leiming, Borjiginb Tenger, Knollc Andrew H, et al. Sheet-like microfossils from hydrothermally influenced basinal cherts of thelower Cambrian (Terreneuvian) Niutitang Formation, Guizhou, South China[J]. Palword, 2016, 350: 1−11.
-
图(9)
表(2)
计量
- 文章访问数: 50
- PDF下载数: 10
- 施引文献: 0