Geochronology and geochemistry of the Early Yanshanian magmatic rocks in southeastern Guangxi: Geological implication
-
摘要:
对桂东南南渡、昙容地区中基性岩浆岩展开岩相学、年代学、全岩地球化学和Sr-Nd同位素研究, 结果表明南渡、昙容中基性岩浆岩主体分别为二长岩和霓辉正长岩, 锆石U-Pb年龄分别为159.8 Ma和156.8 Ma, 均形成于晚侏罗世. 南渡二长岩偏基性, 昙容正长岩偏中性, 在SiO2-K2O图上, 样品整体为钾玄岩系列. 轻稀土元素明显富集于重稀土元素, 总体表现为轻稀土富集右倾型, 其中南渡样品还表现出明显Ba负异常, 昙容样品表现出明显Sr、Ti负异常. 同位素特征显示南渡样品的ISr值为0.70554~0.70959, εNd(t)值为-10.58~-0.75, 主要落在富集地幔且靠近全球硅酸盐地球区域; 昙容样品的ISr值为0.69033-0.69615, εNd(t)值均为0.36, 主要落在亏损地幔与富集地幔之间. 综上所述, 研究区晚中生代处于古太平洋板块西向俯冲的弧后伸展构造背景. 其中南渡二长岩样品应为由富集地幔部分熔融形成, 幔源岩浆在上升过程中受到地壳物质的混染, 存在一定量的斜长石分离结晶作用; 而昙容霓辉正长岩可能是在富集地幔部分熔融的影响下, 受热导致新生下地壳部分熔融形成.
Abstract:The paper studies the petrography, geochronology, whole-rock geochemistry, and Sr-Nd isotope of the intermediate-basic magmatic rocks in Nandu and Tanrong areas of southeastern Guangxi. The results show that the main rock types of Nandu and Tanrong intermediate-basic magmatic rocks are monzonite and aegirine-augite syenite, with the zircon U-Pb ages of 159.8 Ma and 156.8 Ma, respectively, indicating both formed during the Late Jurassic. The Nandu monzonite is more basic, while the Tanrong syenite is relatively intermediate. In the SiO2-K2O diagram, all samples plot within the shoshonitic series. The LREEs are significantly enriched relative to HREEs, exhibiting an overall right- dipping pattern. The Nandu samples show obvious negative Ba anomalies, while Tanrong samples distinct negative Sr and Ti anomalies. The isotope characteristics reveal that the ISr values of Nandu samples range from 0.70554 to 0.70959, with the εNd(t) values from -10.58 to -0.75, mostly falling within the enriched mantle and close to the Bulk Silicate Earth(BSE) area. The ISr values of Tanrong samples are 0.69033-0.69615, with the εNd(t) value of 0.36, mainly plotting between depleted mantle and enriched mantle fields. In summary, the study area was in a back-arc extensional tectonic setting associated with the westward subduction of Paleo-Pacific Plate during the Late Mesozoic. The Nandu monzonite samples were likely formed by partial melting of enriched mantle material, with the mantle-derived magma contaminated by crustal material during ascent, accompanied by a certain degree of plagioclase fractional crystallization, while the Tanrong aegirine-augite syenite was probably generated by partial melting of newly formed lower crust, induced by heat under the influence of partial melting of enriched mantle.
-
Key words:
- Jurassic period /
- magmatic rock /
- zircon U-Pb dating /
- geochemistry /
- southeastern Guangxi
-
-
[1] 毛景文, 谢桂青, 李晓峰, 等. 华南地区中生代大规模成矿作用与岩石圈多阶段伸展[J]. 地学前缘, 2004, 11(1): 45-55.
Mao J W, Xie G Q, Li X F, et al. Mesozoic large scale mineralization and multiple lithospheric extension in South China[J]. Earth Science Frontiers, 2004, 11(1): 45-55.
[2] 王光杰, 滕吉文, 张中杰. 中国华南大陆及陆缘地带的大地构造基本格局[J]. 地球物理学进展, 2000, 15(3): 25-44.
Wang G J, Teng J W, Zang Z J. The continental structure pattern of South China and its marginal regions[J]. Progress in Geophysics, 2000, 15(3): 25-44.
[3] 刘兴源. 桂东南地区晚中生代岩浆岩成因及其地球动力学意义[D]. 桂林: 桂林理工大学, 2022.
Liu X Y. Petrogenesis of Late Mesozoic granites in southeastern Guangxi and their geodynamic implications[D]. Guilin: Guilin University of Technology, 2022.
[4] 李衣鑫, 康志强, 许继峰, 等. 桂东南早白垩世晚期火山岩年代学、地球化学特征及地质意义[J]. 地球科学, 2023, 48(8): 2872-2887.
Li Y X, Kang Z Q, Xu J F, et al. Chronological, geochemical characteristics and geological significance of volcanic rocks in the late Early Cretaceous in southeast Guangxi[J]. Earth Science, 2023, 48 (8): 2872-2887.
[5] 刘迪, 康志强, 许继峰, 等. 桂东南马山玄武岩年代学、地球化学特征及成因意义[J]. 桂林理工大学学报, 2019, 39(4): 806-816.
Liu D, Kang Z Q, Xu J F, et al. Chronology, geochemistry and genetic significance of Mashan basalt in southeast Guangxi[J]. Journal of Guilin University of Technology, 2019, 39(4): 806-816.
[6] Zhou X M, Li W X. Origin of Late Mesozoic igneous rocks in Southeastern China: Implications for lithosphere subduction and underplating of mafic magmas[J]. Tectonophysics, 2000, 326(3/4): 269-287.
[7] 李程. 广西岑溪市新塘火成杂岩体的演化及其地质意义[D]. 桂林: 桂林理工大学, 2018.
Li C. The evolution and geological significance of complex rock mass in Xintang City, Cenxi City, Guangxi[D]. Guilin: Guilin University of Technology, 2018.
[8] 劳妙姬, 邹和平, 杜晓东, 等. 广西横县马山晚侏罗世钾玄质侵入岩的年代学和地球化学研究: 兼论钦杭成矿带西南段燕山期构造背景[J]. 地学前缘, 2015, 22(2): 95-107.
Lao M J, Zou H P, Du X D, et al. Geochronology and geochemistry of the Mashan Late Jurassic shoshonitic intrusives in Hengxian, Guangxi: With a discussion on Yanshanian tectonic settings of the southwestern segment of Qinzhou-Hangzhou metallogenic belt[J]. Earth Science Frontiers, 2015, 22(2): 95-107.
[9] 陈新跃, 王岳军, 张玉芝, 等. 桂东南南渡正长岩年代学、地球化学特征及其构造意义[J]. 大地构造与成矿学, 2013, 37(2): 284-293.
Chen X Y, Wang Y J, Zhang Y Z, et al. Geochronology and geochemical characteristics of the Nandu syenite in SE Guangxi and its implications [J]. Geotectonica et Metallogenia, 2013, 37(2): 284-293.
[10] 周鹏程, 秦亚, 杨启军, 等. 桂东南云开地区南渡钾玄质侵入岩的年代学、地球化学及其地质意义[J]. 桂林理工大学学报, 2023, 43 (4): 535-546.
Zhou P C, Qin Y, Yang Q J, et al. Chronology, geochemistry and its geological significance of Nandu shoshonitic pluton in Yunkai area, southeastern Guangxi[J]. Journal of Guilin University of Technology, 2023, 43(4): 535-546.
[11] 刘洋, 方念乔, 强萌麟, 等. 粤桂地区白垩纪中期安山岩年代学、地球化学特征及其构造意义[J]. 现代地质, 2021, 35(4): 968-980.
Liu Y, Fang N Q, Qiang M L, et al. Geochronology, geochemistry, and tectonic significance of mid-Cretaceous andesites in Guangxi and Guangdong[J]. Geoscience, 2021, 35(4): 968-980.
[12] 强萌麟. 南海北部陆缘白垩纪安山岩基本特征及其与东南沿海安山岩对比[D]. 北京: 中国地质大学, 2016.
Qiang M L. The basic characteristics of cretaceous andesites in the northern margin of South China Sea and its comparison with the andesites of southeast China[D]. Beijing: China University of Geosciences, 2016.
[13] 张伯友, 石满全, 杨树锋, 等. 古特提斯造山带在华南两广交界地区的新证据[J]. 地质论评, 1995, 41(1): 1-6.
Zhang B Y, Shi M Q, Yang S F, et al. New evidence of the paleotethyan orogenic belt on the Guangdong-Guangxi border region, south China [J]. Geological Review, 1995, 41(1): 1-6.
[14] 覃小锋, 夏斌, 周府生, 等. 广西云开地区元古代不整合事件的确定及其构造意义[J]. 现代地质, 2007, 21(1): 22-30.
Qin X F, Xia B, Zhou F S, et al. Confirm of proterozoic unconformity event in the Yunkai area of Guangxi and its tectonic significance[J]. Geoscience, 2007, 21(1): 22-30.
[15] 周永章, 张恩, 陈炳辉, 等. 华南云开变质地体基底与成矿[J]. 矿床地质, 2002, 21(S1): 323-325.
Zhou Y Z, Zhang E, Chen B H, et al. Basement and its mineralization of Yunkai metamorphic block, South China[J]. Mineral Deposits, 2002, 21(S1): 323-325.
[16] 李献华. 广西北部新元古代花岗岩锆石U-Pb年代学及其构造意义[J]. 地球化学, 1999, 28(1): 1-9.
Li X H. U-Pb zircon ages of granites from northern Guangxi and their tectonic significance[J]. Geochimica, 1999, 28(1): 1-9.
[17] 吕劲松, 张雪辉, 孙建东, 等. 钦杭成矿带东段燕山期中酸性岩浆活动时空演化与成矿规律[J]. 岩石学报, 2017, 33(11): 3635- 3658.
Lv J S, Zhang X H, Sun J D, et al. Spatiotemporal evolution and metallogenic regularity of felsic rocks in the Yanshanian of the eastern segment Qinhang metallogenic belt, South China[J]. Acta Petrologica Sinica, 2017, 33(11): 3635-3658.
[18] 徐畅, 王岳军, 张玉芝, 等. 云开池垌志留纪辉长岩体的年代学、地球化学特征及构造意义[J]. 地球科学, 2019, 44(4): 1202-1216.
Xu C, Wang Y J, Zhang Y Z, et al. Geochronological and geochemical constraints of Chidong Silurian gabbroic pluton in Yunkai domain and its tectonic implications[J]. Earth Science, 2019, 44(4): 1202-1216.
[19] 陈志刚, 李献华, 李武显, 等. 赣南全南正长岩的SHRIMP锆石U-Pb年龄及其对华南燕山早期构造背景的制约[J]. 地球化学, 2003, 32(3): 223-229.
Chen Z G, Li X H, Li W X, et al. SHRIMP U-Pb zircon age of the Quannan syenite, southern Jiangxi: Constraints on the early Yanshanian tectonic setting of SE China[J]. Geochimica, 2003, 32(3): 223-229.
[20] Liu Y S, Gao S, Hu Z C, et al. Continental and oceanic crust recycling- induced melt peridotite interactions in the Trans-North China orogen: U-Pb dating, Hf isotopes and trace elements in zircons from mantle xenoliths[J]. Journal of Petrology, 2010, 51(1/2): 537-571.
[21] Andersen T. Correction of common lead in U-Pb analyses that do not report 204Pb[J]. Chemical Geology, 2002, 192(1/2): 59-79.
[22] Ludwig K R. User's manual for Isoplot 3.6: A geochronological toolkit for Microsoft Excel[R]. Berkeley Geochronology Center, 2003.
[23] 李岱鲜, 康志强, 刘迪, 等. 桂东南云开地区回龙岩体的年代学、地球化学特征及其地质意义[J]. 现代地质, 2020, 34(5): 1015-1027.
Li D X, Kang Z Q, Liu D, et al. Geochronological, geochemical and geological significance of Huilong gabbroic pluton in southeastern Guangxi[J]. Geoscience, 2020, 34(5): 1015-1027.
[24] 梁细荣, 韦刚健, 李献华, 等. 利用MC-ICPMS精确测定143Nd/144Nd和Sm/Nd比值[J]. 地球化学, 2003, 32(1): 91-96.
Liang X R, Wei G J, Li X H, et al. Precise measurement of 143Nd/144Nd and Sm/Nd ratios using multiple-collectors inductively coupled plasma-mass spectrometer (MC-ICPMS)[J]. Geochimica, 2003, 32 (1): 91-96.
[25] Hoskin P W O, Black L P. Metamorphic zircon formation by solid-state recrystallization of protolith igneous zircon[J]. Journal of Metamorphic Geology, 2000, 18(4): 423-439.
[26] Le Maitre R W. A proposal by the IUGS Subcommission on the systematics of igneous rocks for a chemical classification of volcanic rocks based on the total alkali silica (TAS) diagram[J]. Australian Journal of Earth Sciences, 1984, 31(2): 243-255.
[27] Miyashiro A. Volcanic rock series in island arcs and active continental margins[J]. American Journal of Science, 1974, 274(4): 321-355.
[28] Sun S S, McDonough W F. Chemical and isotopic systematics of oceanic basalts: Implications for mantle composition and processes[J]. Geological Society, London, Special Publications, 1989, 42: 313-345.
[29] Taylor S R. McLennan S M. The continental crust: Its composition and evolution[M]. Oxford: Blackwell Scientific Publications, 1985.
[30] 王金荣, 陈万峰, 张旗, 等. N-MORB和E-MORB数据挖掘——玄武岩判别图及洋中脊源区地幔性质的讨论[J]. 岩石学报, 2017, 33 (3): 993-1005.
Wang J R, Chen W F, Zhang Q, et al. Preliminary research on data mining of N-MORB and E-MORB: Discussion on method of the basalt discrimination diagrams and the character of MORB's mantle source [J]. Acta Petrologica Sinica, 2017, 33(3): 993-1005.
[31] 陈万峰, 王金荣, 张旗, 等. 洋岛和洋底高原玄武岩数据挖掘: 地球化学特征及其与MORB的对比[J]. 地质学报, 2017, 91(11): 2443-2455.
Chen W F, Wang J R, Zhang Q, et al. Data mining of ocean island basalt and ocean plateau basalt: Geochemical characteristics and comparison with MORB[J]. Acta Geologica Sinica, 2017, 91(11): 2443-2455.
[32] 杨婧, 王金荣, 张旗, 等. 弧后盆地玄武岩(BABB)数据挖掘: 与MORB及IAB的对比[J]. 地球科学进展, 2016, 31(1): 66-77.
Yang J, Wang J R, Zhang Q, et al. Back-arc basin basalt (BABB) data mining: Comparison with MORB and IAB[J]. Advances in Earth Science, 2016, 31(1): 66-77.
[33] 王鲲鹏, 樊双虎, 彭小华. 新疆乌什塔拉地区晚泥盆世火山岩地球化学特征及构造意义[J]. 西北地质, 2014, 47(2): 23-29.
Wang K P, Fan S H, Peng X H. Geochemical characteristics and tectonic significance of the Late Devonian volcanics in Wushentara area, Xinjiang[J]. Northwestern Geology, 2014, 47(2): 23-29.
[34] 孙涛, 周新民. 中国东南部晚中生代伸展应力体制的岩石学标志[J]. 南京大学学报(自然科学), 2002, 38(6): 737-746.
Sun T, Zhou X M. Late Mesozoic extension in Southeast China: Petrologic symbols[J]. Journal of Nanjing University (Natural Sciences), 2002, 38(6): 737-746.
[35] Xie W, Song X Y, Deng Y F, et al. Geochemistry and petrogenetic implications of a Late Devonian mafic-ultramafic intrusion at the southern margin of the Central Asian Orogenic Belt[J]. Lithos, 2012, 144-145: 209-230.
[36] O'Hara M J, Yoder H S Jr. Formation and fractionation of basic magmas at high pressures[J]. Scottish Journal of Geology, 1967, 3 (1): 67-117.
[37] Hébert R, Guilmette C, Dostal J, et al. Miocene post-collisional shoshonites and their crustal xenoliths, Yarlung Zangbo Suture Zone southern Tibet: Geodynamic implications[J]. Gondwana Research, 2014, 25(3): 1263-1271.
[38] Harris P G, Middlemost E A K. The evolution of kimberlites[J]. Lithos, 1970, 3(1): 77-88.
[39] 甘成势, 王岳军, 蔡永丰, 等. 南岭地区温公岩体的岩石成因及其构造指示[J]. 地球科学, 2016, 41(1): 17-34.
Gan C S, Wang Y J, Cai Y F, et al. The petrogenesis and tectonic implication of Wengong intrusion in the Nanling Range[J]. Earth Science, 2016, 41(1): 17-34.
[40] 张靖祎, 彭头平, 范蔚茗, 等. 缅甸密支那早白垩世钾玄质岩石成因及其大地构造意义[J]. 大地构造与成矿学, 2021, 45(3): 553- 569.
Zhang J Y, Peng T P, Fan W M, et al. Petrogenesis of the Early Cretaceous shoshonitic rocks in Myitkina of Myanmar and its tectonic implications[J]. Geotectonica et Metallogenia, 2021, 45(3): 553- 569.
[41] 潘荣, 朱筱敏, 苏春乾, 等. 黑龙江伊春市北部白垩系美丰组钾玄岩系列的厘定及地球化学特征[J]. 高校地质学报, 2013, 19(2): 316-326.
Pan R, Zhu X M, Su C Q, et al. Redefinition and geochemical characteristics of the Mesozoic shoshonite rock series of the Meifeng Formation in northern Yichun City, Heilongjiang Province[J]. Geological Journal of China Universities, 2013, 19(2): 316-326.
[42] 朱强, 施珂, 吴礼彬, 等. 扬子板块新元古代中期的持续俯冲作用: 来自南华纪岛弧火山岩年代学和岩石地球化学新证据[J]. 地学前缘, 2020, 27(4): 17-32.
Zhu Q, Shi K, Wu L B, et al. Continued subduction of the Yangtze Plate in the Middle Neoproterozoic: New evidence based on the geochronology and petro-geochemistry of island arc volcanic rocks in the Nanhua Period[J]. Earth Science Frontiers, 2020, 27(4): 17-32.
[43] 赵振华. 关于岩石微量元素构造环境判别图解使用的有关问题[J]. 大地构造与成矿学, 2007, 31(1): 92-103.
Zhao Z H. How to use the trace element diagrams to discriminate tectonic settings[J]. Geotectonica et Metallogenia, 2007, 31(1): 92- 103.
[44] Pearce J A. Trace element characteristics of lavas from destructive plate boundaries[M]//Thorpe R S. Andesites: Orogenic Andesites and Related Rocks. New York: John Wiley and Sons, 1982: 528-548.
[45] McKenzie D, Bickle M J. The volume and composition of melt generated by extension of the lithosphere[J]. Journal of Petrology, 1988, 29(3): 625-679.
[46] 秦涛. 大兴安岭中段晚中生代火山岩地球化学与岩石成因研究[D]. 长春: 吉林大学, 2022.
Qin T. The geochemical and petrogenetic studies on Late Mesozoic volcanic rocks in the central segment of Great Xing'an Range[D]. Changchun: Jilin University, 2022.
[47] Jiang Y H, Jiang S Y, Dai B Z, et al. Middle to Late Jurassic felsic and mafic magmatism in southern Hunan Province, southeast China: Implications for a continental arc to rifting[J]. Lithos, 2009, 107(3/4): 185-204.
[48] 舒良树. 华南构造演化的基本特征[J]. 地质通报, 2012, 31(7): 1035-1053.
Shu L S. An analysis of principal features of tectonic evolution in South China Block[J]. Geological Bulletin of China, 2012, 31(7): 1035- 1053.
[49] 张旗, 金惟俊, 李承东, 等. 中国东部燕山期大规模岩浆活动与岩石圈减薄: 与大火成岩省的关系[J]. 地学前缘, 2009, 16(2): 21- 51.
Zhang Q, Jin W J, Li C D, et al. Yanshanian large-scale magmatism and lithosphere thinning in eastern China: Relation to large igneous province[J]. Earth Science Frontiers, 2009, 16(2): 21-51.
[50] 李武显, 周新民. 古太平洋岩石圈消减与中国东南部晚中生代火成岩成因——岩石圈消减与玄武岩底侵相结合模式的补充证据[J]. 大地构造与成矿学, 2001, 25(1): 55-63.
Li W X, Zhou X M. Subduction of the Paleo-Pacific Plate and origin of Late Mesozoic igneous rocks in southeastern China: Some supplement evidences for the model of lithosphere subduction and underplating of mafic magma[J]. Geotectonica et Metallogenia, 2001, 25(1): 55-63.
[51] 刘凯, 厉子龙, 徐维光, 等. 华南中生代岩浆岩时空分布和迁移与古太平洋板块俯冲过程[J]. 矿物岩石地球化学通报, 2016, 35 (6): 1141-1155.
Liu K, Li Z L, Xu W G, et al. The spatial-temporal distributions and migrations of mesozoic magmaism in South China and subduction process of the Paleo-Pacific Plate[J]. Bulletin of Mineralogy, Petrology and Geochemistry, 2016, 35(6): 1141-1155.
[52] Charvet J, Lapierre H, Yu Y W. Geodynamic significance of the Mesozoic volcanism of southeastern China[J]. Journal of Southeast Asian Earth Sciences, 1994, 9(4): 387-396.
[53] 周新民, 李武显. 中国东南部晚中生代火成岩成因: 岩石圈消减和玄武岩底侵相结合的模式[J]. 自然科学进展, 2000, 10(3): 240- 247.
Zhou X M, Li W X. Origin of Late Mesozoic igneous rocks in Southeast China: A model combining lithospheric reduction and basalt bottom intrusion[J]. Progress in Natural Science, 2000, 10(3): 240-247. (in Chinese)
[54] Gilder S A, Gill J, Coe R S, et al. Isotopic and paleomagnetic constraints on the Mesozoic tectonic evolution of South China[J]. Journal of Geophysical Research: Solid Earth, 1996, 101(B7): 16137-16154.
[55] 李献华, 周汉文, 刘颖, 等. 桂东南钾玄质侵入岩带及其岩石学和地球化学特征[J]. 科学通报, 1999, 44(18): 1992-1998.
Li X H, Zhou H W, Liu Y, et al. Shoshonitic intrusive suite in SE Guangxi: Petrology and geochemistry[J]. Chinese Science Bulletin, 2000, 45(7): 653-659.
[56] 陈志刚, 李献华, 李武显. 全南正长岩的地球化学特征及成因[J]. 地质论评, 2002, 48(S1): 77-83.
Chen Z G, Li X H, Li W X. Geochemical characteristics and origin of the Quannan syenite[J]. Geological Review, 2002, 48(S1): 77-83.
[57] 王文东, 刘涛, 周传芳, 等. 黑龙江富源沟晚三叠世中-基性火山岩的厘定及地质意义[J]. 地质与资源, 2023, 32(6): 670-680. doi: 10.13686/j.cnki.dzyzy.2023.06.003
Wang W D, Liu T, Zhou C F, et al. Identification of the Late Triassic Fuyuangou intermediate-basic volcanic rocks in Heilongjiang Province: Geological implication[J]. Geology and Resources, 2023, 32(6): 670-680. doi: 10.13686/j.cnki.dzyzy.2023.06.003
[58] Meschede M. A method of discriminating between different types of mid-ocean ridge basalts and continental tholeiites with the Nb-Zr-Y diagram[J]. Chemical Geology, 1986, 56(3/4): 207-218.
[59] 李强, 程学芹, 王艳凯, 等. 大兴安岭北段盘古河上游早古生代中基性杂岩体U-Pb年龄、地球化学特征及其地质意义[J]. 地质论评, 2024, 70(1): 155-174.
Li Q, Cheng X Q, Wang Y K, et al. U-Pb age, geochemical characteristics of the Early Paleozoic intermediate-basic complex in the upper reaches of Pangu River, northern Great Hinggan Mountains and their geological implications[J]. Geological Review, 2024, 70(1): 155-174.
-
下载:
图(11)
计量
- 文章访问数: 44
- PDF下载数: 24
- 施引文献: 0