赣南地区寒武纪高滩组碎屑锆石U-Pb年龄和Hf同位素特征及地质意义
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摘要
寒武纪高滩组广泛分布于赣南武功山-雩山地区,主体为一套浅变质砂岩夹板岩的复理石建造。为分析其物源,并对源区地壳生长和构造演化提供约束,本文对采自高滩组的变长石石英杂砂岩进行了LA-ICP-MS碎屑锆石U-Pb年代学和Hf同位素研究。锆石U-Pb年龄数据显示2 500 Ma、1 100～900 Ma和900～700 Ma 3个主要年龄峰值。2 500 Ma的年龄峰值代表了新太古代末期—古元古代的古陆核生长事件。1 100～900 Ma和900～700 Ma两个峰最显著,表明Rodinia超大陆聚合裂解在华南地区的响应,为该区寒武纪地层提供了主要物源。此外,3 003 Ma锆石年龄的捕获说明,华夏地块可能存在太古宙地壳基底。Hf同位素数据表明,源区锆石结晶多为古老地壳组分部分熔融产生的岩浆。结合锆石年龄数据分析认为,华南地区存在强烈的新元古代岩浆活动,该时期岩浆活动主要是古老地壳物质的再循环。
The Cambrian Gaotan Formation is widely distributed in the Wugongshan-Yushan area of Gannan.It is mainly a set of flysch composed of low metamorphic sandstone and slate.The researchers have little research about it and lack of the latest data.In order to analyze its provenance and provide constraints on crustal growth and tectonic evolution in the source area, the LA-ICP-MS detrital zircon U-Pb geochronology and Hf isotope study were carried out on a sandstone from the Gaotan Formation.The U-Pb age data shows three peaks of 2 500 Ma, 1 100～900 Ma and 900～700 Ma.The age peak of 2 500 Ma represents crustal growth event in the late Neoarchean-Paleoproterozoic.The two peaks of 1100～900 Ma and 900～700 Ma are the most significant,which indicates that the response of the amalgamation and breakup of the Rodinia supercontinent in southern China provides the main provenance for the Cambrian strata in study area.In addition,the capture of 3 003 Ma sugggets that the Cathysia block may have the Archean crustal base;Hf isotope data indicates that most of the zircon in the provenance region crystallized from the magma produced by partial melting of the ancient crustal materials.Combined with the analysis of zircon age data,there is a strong Neoproterozoic magmatism in South China,and the magmatism during this period is mainly the recycling of the magma produced by the melting of ancient crustal materials.
The Cambrian Gaotan Formation is widely distributed in the Wugongshan-Yushan area of Gannan.It is mainly a set of flysch composed of low metamorphic sandstone and slate.The researchers have little research about it and lack of the latest data.In order to analyze its provenance and provide constraints on crustal growth and tectonic evolution in the source area, the LA-ICP-MS detrital zircon U-Pb geochronology and Hf isotope study were carried out on a sandstone from the Gaotan Formation.The U-Pb age data shows three peaks of 2 500 Ma, 1 100～900 Ma and 900～700 Ma.The age peak of 2 500 Ma represents crustal growth event in the late Neoarchean-Paleoproterozoic.The two peaks of 1100～900 Ma and 900～700 Ma are the most significant,which indicates that the response of the amalgamation and breakup of the Rodinia supercontinent in southern China provides the main provenance for the Cambrian strata in study area.In addition,the capture of 3 003 Ma sugggets that the Cathysia block may have the Archean crustal base;Hf isotope data indicates that most of the zircon in the provenance region crystallized from the magma produced by partial melting of the ancient crustal materials.Combined with the analysis of zircon age data,there is a strong Neoproterozoic magmatism in South China,and the magmatism during this period is mainly the recycling of the magma produced by the melting of ancient crustal materials.
引文
[1]舒良树.华南前泥盆纪构造演化:从华夏地块到加里东期造山带[J].高校地质学报,2006(4):418-431.
[2]Wang J,Shu L,Santosh M.U-Pb and Lu-Hf isotopes of detrital zircon grains from Neoproterozoic sedimentary rocks in the central Jiangnan Orogen,South China:Implications for Precambrian crustal evolution[J].Precambrian Research,2017,294:175-188.
[3]舒良树.华南构造演化的基本特征[J].地质通报,2012,31(7):1035-1053.
[4]周恳恳,牟传龙,葛祥英,等.新一轮岩相古地理编图对华南重大地质问题的反映--早古生代晚期“华南统一板块”演化[J].沉积学报,2017,35(3):449-459.
[5]Yao J,Shu L,Santosh M,et al.Precambrian crustal evolution of the South China Block and its relation to supercontinent history:Constraints from U-Pb ages,Lu-Hf isotopes and REE geochemistry of zircons from sandstones and granodiorite[J].Precambrian Research,2012,208-211:19-48.
[6]黄仁波,刘家润,杨振宇,等.浙江江山寒武系碎屑锆石U-Pb年龄与沉积指向构造及其古地理意义[J].高校地质学报,2016,22(3):474-485.
[7]沈渭洲,舒良树,向磊,等.江西井冈山地区早古生代沉积岩的地球化学特征及其对沉积环境的制约[J].岩石学报,2009,25(10):2442-2458.
[8]舒良树,于津海,贾东,等.华南东段早古生代造山带研究[J].地质通报,2008(10):1581-1593.
[9]Shu LS,Jahn BM,Charvet J,et al.Early Paleozoic depositional environment and intracontinental orogeny in the Cathaysia Block(South China):implications from stratigraphic,structural,geochemical and geochronologic evidence.American Journal of Science,2014,314:154-186.
[10]Rong J Y,Zhan R B,Xu H G,et al.Expansion of the Cathaysian Oldland through the Ordovician-Silurian transition:Emerging evidence and possible dynamics[J].Science China Earth Sciences,2010,53(1):1-17.
[11]周博文,曾国丰,徐文坦,等.赣南地区早南华世钾质斑脱岩的发现及其大地构造意义[J].地质学刊,2018,42(1):95-107.
[12]江西省地质矿产勘查开发局,江西省地质调查研究院.江西省区域地质志.北京:地质出版社,2012.
[13]Liu Yong-sheng,Gao Shan,Hu Zhao-chu,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 of mantle xenoliths[J].Journal of Petrologr,2010,51(1-2):537-571.
[14]Ludwig K R.ISOPLOT 3.00:A Geochronological Toolkit for Microsoft Excel[J].Berkeley Geochronology Center,California:Berkeley 2003,:39.
[15]S?derlund U,Patchett P J,Vervoort J D.The 176 Lu decay constant determined by Lu-Hf and U-Pb isotope systematics of Precambrian mafic intrusions[J].Earth and Planetary Science Letters,2004,219(3):311-324.
[16]Bouvier A,Vervoort J D,Patchett P J.The Lu-Hf and Sm-Nd isotopic composition of CHUR:constraints from unequilibrated chon drites and implications for the bulk composition of terrestrial plan ets[J].Earth and Planetary Science Letters,2008,273(1):48-57.
[17]Griffin W L,Pearson N J,Belousova E.The Hf isotope composi tion of cratonic mantle:LAM-MC-ICPMS analysis of zircon megacrysts in kimberlites[J].Geochimica et Cosmochimica Ac ta,2000,64(1):133-147.
[18]钱一雄,王亮,康志宏,等.塔西南奥陶系玛列兹肯群碎屑岩年代学研究[J].新疆地质,2018,36(01):30-37.
[19]Hawkesworth C J,Dhuime B,Pietranik A B,et al.The generation and evolution of the continental crust[J].Journal of the Geological Society,2010,167(2):229-248.
[20]翁凯,徐学义,马中平,等.西准噶尔谢米斯台地区中泥盆统呼吉尔斯特组砂岩源区示踪[J].新疆地质,2017,35(02):127-133.
[21]Yan C,Shu L,Santosh M,et al.The Precambrian tectonic evolution of the western Jiangnan Orogen and western Cathaysia Block:Evidence from detrital zircon age spectra and geochemistry of clastic rocks[J].Precambrian Research,2015,268:33-60.
[22]Yao J,Shu L,Santosh M.Detrital zircon U-Pb geochronology,Hfisotopes and geochemistry-New clues for the Precambrian crustal evolution of Cathaysia Block,South China[J].Gondwana Research,2011,20(2):553-567.
[23]Li Xian-hua,Li Wu-xian,Li Zheng-xiang,et al.amalgamation between the Yangtze and Cathaysia Blocks in South China:Constraints from SHRIMP U-Pb zircon ages,geochemistry and Nd-Hf isotopes of the Shuangxiwu volcanic rocks[J].Precambrian Research,2009,174:117-128.
[24]Li Xian-hua.Timing of the Cathaysia block formation:Constraints from SHRIMP U-Pb zircon geochronology[J].Episodes,1997,20:188-192.
[25]于津海,Y.S.O’Reilly,王丽娟,等.华夏地块古老物质的发现和前寒武纪地壳的形成[J].科学通报,2007(1):11-18.
[26]向磊,舒良树.华南东段前泥盆纪构造演化:来自碎屑锆石的证据[J].中国科学:地球科学,2010,40(10):1377-1388.
[27]吴福元,李献华,郑永飞,等.Lu-Hf同位素体系及其岩石学应用[J].岩石学报,2007(2):185-220.
[2]Wang J,Shu L,Santosh M.U-Pb and Lu-Hf isotopes of detrital zircon grains from Neoproterozoic sedimentary rocks in the central Jiangnan Orogen,South China:Implications for Precambrian crustal evolution[J].Precambrian Research,2017,294:175-188.
[3]舒良树.华南构造演化的基本特征[J].地质通报,2012,31(7):1035-1053.
[4]周恳恳,牟传龙,葛祥英,等.新一轮岩相古地理编图对华南重大地质问题的反映--早古生代晚期“华南统一板块”演化[J].沉积学报,2017,35(3):449-459.
[5]Yao J,Shu L,Santosh M,et al.Precambrian crustal evolution of the South China Block and its relation to supercontinent history:Constraints from U-Pb ages,Lu-Hf isotopes and REE geochemistry of zircons from sandstones and granodiorite[J].Precambrian Research,2012,208-211:19-48.
[6]黄仁波,刘家润,杨振宇,等.浙江江山寒武系碎屑锆石U-Pb年龄与沉积指向构造及其古地理意义[J].高校地质学报,2016,22(3):474-485.
[7]沈渭洲,舒良树,向磊,等.江西井冈山地区早古生代沉积岩的地球化学特征及其对沉积环境的制约[J].岩石学报,2009,25(10):2442-2458.
[8]舒良树,于津海,贾东,等.华南东段早古生代造山带研究[J].地质通报,2008(10):1581-1593.
[9]Shu LS,Jahn BM,Charvet J,et al.Early Paleozoic depositional environment and intracontinental orogeny in the Cathaysia Block(South China):implications from stratigraphic,structural,geochemical and geochronologic evidence.American Journal of Science,2014,314:154-186.
[10]Rong J Y,Zhan R B,Xu H G,et al.Expansion of the Cathaysian Oldland through the Ordovician-Silurian transition:Emerging evidence and possible dynamics[J].Science China Earth Sciences,2010,53(1):1-17.
[11]周博文,曾国丰,徐文坦,等.赣南地区早南华世钾质斑脱岩的发现及其大地构造意义[J].地质学刊,2018,42(1):95-107.
[12]江西省地质矿产勘查开发局,江西省地质调查研究院.江西省区域地质志.北京:地质出版社,2012.
[13]Liu Yong-sheng,Gao Shan,Hu Zhao-chu,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 of mantle xenoliths[J].Journal of Petrologr,2010,51(1-2):537-571.
[14]Ludwig K R.ISOPLOT 3.00:A Geochronological Toolkit for Microsoft Excel[J].Berkeley Geochronology Center,California:Berkeley 2003,:39.
[15]S?derlund U,Patchett P J,Vervoort J D.The 176 Lu decay constant determined by Lu-Hf and U-Pb isotope systematics of Precambrian mafic intrusions[J].Earth and Planetary Science Letters,2004,219(3):311-324.
[16]Bouvier A,Vervoort J D,Patchett P J.The Lu-Hf and Sm-Nd isotopic composition of CHUR:constraints from unequilibrated chon drites and implications for the bulk composition of terrestrial plan ets[J].Earth and Planetary Science Letters,2008,273(1):48-57.
[17]Griffin W L,Pearson N J,Belousova E.The Hf isotope composi tion of cratonic mantle:LAM-MC-ICPMS analysis of zircon megacrysts in kimberlites[J].Geochimica et Cosmochimica Ac ta,2000,64(1):133-147.
[18]钱一雄,王亮,康志宏,等.塔西南奥陶系玛列兹肯群碎屑岩年代学研究[J].新疆地质,2018,36(01):30-37.
[19]Hawkesworth C J,Dhuime B,Pietranik A B,et al.The generation and evolution of the continental crust[J].Journal of the Geological Society,2010,167(2):229-248.
[20]翁凯,徐学义,马中平,等.西准噶尔谢米斯台地区中泥盆统呼吉尔斯特组砂岩源区示踪[J].新疆地质,2017,35(02):127-133.
[21]Yan C,Shu L,Santosh M,et al.The Precambrian tectonic evolution of the western Jiangnan Orogen and western Cathaysia Block:Evidence from detrital zircon age spectra and geochemistry of clastic rocks[J].Precambrian Research,2015,268:33-60.
[22]Yao J,Shu L,Santosh M.Detrital zircon U-Pb geochronology,Hfisotopes and geochemistry-New clues for the Precambrian crustal evolution of Cathaysia Block,South China[J].Gondwana Research,2011,20(2):553-567.
[23]Li Xian-hua,Li Wu-xian,Li Zheng-xiang,et al.amalgamation between the Yangtze and Cathaysia Blocks in South China:Constraints from SHRIMP U-Pb zircon ages,geochemistry and Nd-Hf isotopes of the Shuangxiwu volcanic rocks[J].Precambrian Research,2009,174:117-128.
[24]Li Xian-hua.Timing of the Cathaysia block formation:Constraints from SHRIMP U-Pb zircon geochronology[J].Episodes,1997,20:188-192.
[25]于津海,Y.S.O’Reilly,王丽娟,等.华夏地块古老物质的发现和前寒武纪地壳的形成[J].科学通报,2007(1):11-18.
[26]向磊,舒良树.华南东段前泥盆纪构造演化:来自碎屑锆石的证据[J].中国科学:地球科学,2010,40(10):1377-1388.
[27]吴福元,李献华,郑永飞,等.Lu-Hf同位素体系及其岩石学应用[J].岩石学报,2007(2):185-220.