摘要
长期以来,对于承载郯庐断裂全演化过程的肥东群的变质岩石学和年代学的研究一直较为薄弱,诸多的研究主要关注于构造地质学、地球化学及变形时限方面。本文通过对肥东群不同类型岩石的岩相学、热力学和年代学研究,详实地探究了肥东群的变质条件和时限,并充分讨论了肥东群的两期韧性变形时限。研究显示,肥东群普遍经历了角闪岩相的变质,温压条件大致为T=550~650℃和P=0.5~0.9GPa。同时,依据5个二长花岗片麻岩、1个变形花岗岩(167.2±4.6Ma)和1个花岗闪长斑岩岩脉的年龄(130±5Ma)的锆石年龄和前人的年龄数据分析,认为早期的变形以一组倾向南东的面理和线理为代表,其形成的时限可能在133~167Ma时间段。而晚期的变形以一组宽约3~5m NE向的陡倾糜棱岩带为特征,其变形时限可能在122~133Ma。
For a long time,the investigation on the petrology and geochronology for Feidong Group( FDG),which documents the evolution of the Tan-Lu fault,is very limited. A lot of research focused on the structure,geochemistry and deformation geochronology for the FDG. In this contribution,according to the study of petrology,thermodynamics and geochronology for various types of rocks of the FDG,the metamorphic conditions and date of the FDG have been analyzed in detail,and two deformed periods have been defined for the FDG. The study reveals that the FDG had underwent amphibole metamorphism T = 550 ~ 650℃ and P = 0. 5 ~ 0. 9GPa. By the analysis of LA-ICP-MS,five two-feldspar granitic gneisses from the FDG give complex age range from 413 Ma to 2498 Ma with various origin. Meanwhile,the zircon U-Pb ages of 167. 2 ± 4. 6Ma from the deformed granite and 130 ± 5Ma from prophyro grainitic diorite have been confirmed. Combined structural investigation,dating with previous study,two deformation period for the FDG has been distinguished:( 1) the early deformation with a SE dipping foliation and lineation has been conjectured in the 133 ~ 167 Ma,and( 2)the later deformation cropping out as a 3 ~ 5m width of the NE-direction steep mylonitic zone has been defined in the 122 ~ 133 Ma.
引文
Benisek A,Dachs E and Kroll H.2010.A ternary feldspar-mixing mode based on calorimetric data:Development and application Contributions to Mineralogy and Petrology,160(3):327-337
Bhadra S and Bhattacharya A.2007.The barometer tremolite+tschermakite+2albite=2pargasite+8quartz:Constraints from experimental data at unit silica activity,with application to garnetfree natural assemblages.American Mineralogist,92(4):491-502
Bureau of Geology and Mineral Resources of Anhui Province.1987.Regional Geology of Anhui Province.Beijing:Geological Publishing House(in Chinese)
Chen XH,Wang XF,Zhang Q,Chen BL,Chen ZL,Harrison TM and Yin A.2000.Geochronologic study on the formation and evolution of Tan-Lu Fault.Journal of Changchun University of Science and Technology,30(3):215-220(in Chinese with English abstract)
Fletcher CJN,Fitches WR,Rundle CC and Evans JA.1995.Geological and isotopic constraints on the timing of movement in the Tan-Lu Fault Zone,northeastern China.Journal of Southeast Asian Earth Sciences,11(1):15-22
Ge NJ and Zhou DZ.1993.The isotopic dating of metamorphic rock series of Feidong Group,Anhui Province.Geology of Anhui,3(3):22-25(in Chinese with English abstract)
Gilder SA,Leloup PH,Courtillot V,Chen Y,Coe RS,Zhao XX,Xiao WJ,Halim N,CognéJP and Zhu RX.1999.Tectonic evolution of the Tancheng-Lujiang(Tan-Lu)fault via Middle Triassic to Early Cenozoic paleomagnetic data.Journal of Geophysical Research,104(B7):15365-15390
Holland TJB and Blundy JD.1994.Non-ideal interactions in calcic amphiboles and their bearing on amphibole-plagioclase thermometry.Contributions to Mineralogy and Petrology,116(4):433-447
Hsu KJ,Li J,Chen I,Wang Q,Sun S and Sengor AMC.1987.Tectonic evolution of Qinling Mountains,China.Eclogae Geologicae Helvetiae,80(3):735-752
Kang T,Liu XY,Wang J,Nie F and Shi YH.2013.Analysis of metamorphic attribution and geochronology for the Feidong terrane in the east of the Tan-Lu Fault.Acta Petrologica Sinica,29(9):3142-3158(in Chinese with English abstract)
Li SG,Liu DL,Chen YZ,Wang SS,Qiu J,Hu SL and Shang HQ.1993.Time of the blueschist belt formation in central China.Scientia Geologica Sinica,28(1):21-27(in Chinese with English abstract)
Li SG,Jagoutz E,Chen YZ and Li QL.2000.Sm-Nd and Rb-Sr isotopic chronology and cooling history of ultrahigh pressure metamorphic rocks and their country rocks at Shuanghe in the Dabie Mountains,Central China.Geochim.Cosmochim.Acta,64(6):1077-1093
Li XH,Li ZX and Li WX.2014.Detrital zircon U-Pb age and Hf isotope constrains on the generation and reworking of Precambrian continental crust in the Cathaysia Block,South China:A synthesis.Gondwana Research,25(3):1202-1215
Li ZX.1994.Collision between the North and South China blocks:Acrustal-detachment model for suturing in the region east of the Tanlu fault.Geology,22(8):739-742
Lin JL and Fuller M.1990.Paleomagnetism,North and South China collision,and the Tan-Lu fault.Philosophical Transactions of the Royal Society of London A,331(1620):589-598
Lin SF and Li ZX.1995.Collision between the North and South China blocks:A crustal-detachment model for suturing in the region east of the Tanlu fault:Comment and reply.Geology,23(6):574-575
Lin W,Faure M,Wang QC,MoniéP and Panis D.2005.Triassic polyphase deformation in the Feidong-Zhangbaling Massif(eastern China)and its place in the collision between North China and South China blocks.Journal of Asian Earth Sciences,25(1):121-136
Lin W,Shi YH and Wang QC.2009.Exhumation tectonics of the HP-UHP orogenic belt in eastern China:New structural-petrological insights from the Tongcheng massif,eastern Dabieshan.Lithos,109(3-4):285-303
Ludwig KR.2003.User’s Manual for Isoplot/Exersion 3.00:AGeochronological Toolkit for Microsoft Excel.Berkeley Geochronology Center:Special Publication,4:1-70
Nie F,Shi YH,Wang J,Cao S and Shi YH.2014.Investigation on the metamorphic conditions and geochronology for the magnet garnet amphibole in the Tan-Lu Fault Zone(Anhui segment),and discussion of its tectonic attribution.Acta Petrologica Sinica,30(6):1718-1730(in Chinese with English abstract)
Oh CW and Liou JG.1998.A petrogenetic grid for eclogite and related facies under high-pressure metamorphism.Island Arc,7(1-2):36-51
Okay AI and Sengor AMC.1992.Evidence for intracontinental thrust related exhumation of the ultra-high-pressure rocks in China.Geology,20(5):411-414
Ota T,Maruyama M,Parkinson CD and Masago H.2002.Thermobaric structure of the Kokchetav massif from a north-south transect in the Kulet and Saldat-Kol regions.In:Parkinson CD,Katayama I,Liou JG and Maruyama S(eds.).The Diamond-Bearing Kokchetav Massif,Kazakhstan.Tokyo,Japan:Universal Academy Press,Inc.,283-319
Pumpelly R.1866.Geological Researches in China,Mongolia,and Japan,during the Years 1862-1865.London:Smithsonian Institution
Schmid JC,Ratschbacher L,Hacker BR,Gaitzsch I and Dong SW.1999.How did the foreland react?Yangtze foreland fold-and-thrust belt deformation related to exhumation of the Dabie Shan ultrahighpressure continental crust(eastern China).Terra Nova,11(6):266-272
Shi YH,Zhu G and Wang DX.2009.Metamorphic P-T evolution for the garnet amphibolite from Feidong Group in the south of Zhangbaling uplift across Tan-Lu fault and its influence on tectonics.Acta Petrologica Sinica,25(12):3335-3345(in Chinese with English abstract)
Wang EC,Meng QR,Burchfiel BC and Zhang GW.2003.Mesozoic large-scale lateral extrusion,rotation,and uplift of the TongbaiDabie Shan belt in east China.Geology,31(4):307-310
Wang W,Song CZ,Li JH,Ren SL,Zhang Y,Liu H and Yang F.2015.Zircon U-Pb dating for shearing movement on the Feidong segment of the Tan-Lu fault zone.Chinese Journal of Geology,50(3):800-809(in Chinese with English abstract)
Whitney DL and Evans BW.2010.Abbreviations for names of rockforming minerals.American Mineralogist,95(1):185-187
Wu CM and Chen HX.2015a.Revised Ti-in-biotite geothermometer for ilmenite-or rutile-bearing crustal metapelites.Science Bulletin,60(1):116-121
Wu CM and Chen HX.2015b.Calibration of a Ti-in-muscovite geothermometer for ilmenite-and Al2SiO 5-bearing metapelites.Lithos,212-215:122-127
Wu YB and Zheng YF.2004.Genesis of zircon and its constraints on interpretation of U-Pb age.Chinese Science Bulletin,49(15):1554-1569
Xu JW,Zhu G,Tong WX,Cui KR and Liu Q.1987.Formation and evolution of the Tancheng-Lujiang wrench fault system:A major shear system to the northern of the Pacific Ocean.Tectonophysics,134(4):273-310
Xu JW and Zhu G.1994.Tectonic models of the Tan-Lu fault zone,eastern China.International Geology Review,36(8):771-784
Yin A and Nie SY.1993.An indentation model for the North and South China collision and the development of the Tan-Lu and Honam fault systems,eastern Asia.Tectonics,12(4):801-813
Zhang KJ.1997.North and South China collision along the eastern and southern North China margins.Tectonophysics,270(1-2):145-156
Zhang Q,Teyssier C,Dunlap J and Zhu G.2007.Oblique collision between North and South China recorded in Zhangbaling and Fucha Shan(Dabie-Sulu transfer zone).The Geology Society America,434:167-206
Zhang SB and Zheng YF.2013.Formation and evolution of Precambrian continental lithosphere in South China.Gondwana Research,23(4):1241-1260
Zhang ZM,Liou JG and Coleman RG.1984.An outline of the plate tectonics of China.Geol.Soc.Am.Bull.,95(3):295-312
Zhao GC and Cawood PA.2012.Precambrian geology of China.Precambrian Research,222-223:13-54
Zhao T,Zhu G,Lin SZ,Yan LJ and Jiang QQ.2014.Protolith ages and deformation mechanism of metamorphic rocks in the Zhangbaling uplift segment of the Tan-Lu Fault Zone.Science China(Earth Sciences),57(11):2740-2757
Zheng YF.2008.A perspective view on ultrahigh-pressure metamorphism and continental collision in the Dabie-Sulu orogenic belt.Chinese Science Bulletin,53(20):3081-3104
Zhu G,Wang YS,Niu ML,Liu GS and Xie CL.2004.Synorogenic movement of the Tan-Lu fault zone.Earth Science Frontiers,11(3):169-182(in Chinese with English abstract)
Zhu G,Wang YS,Liu GS,Niu ML,Xie CL and Li CC.2005.40Ar/39Ar dating of strike-slip motion on the Tan-Lu Fault Zone,East China.Journal of Structural Geology,27(8):1379-1398
Zhu G,Liu GS,Niu ML,Xie CL,Wang YS and Xiang BW.2009.Syncollisional transform faulting of the Tan-Lu Fault Zone,East China.International Journal of Earth Sciences,98(1):135-155
Zhu G,Zhang L,Xie CL,Niu ML and Wang YS.2009.Geochronological constraints on tectonic evolution of the Tan-Lu fault zone.Chinese Journal of Geology,44(4):1327-1342(in Chinese with English abstract)
Zhu G,Niu ML,Xie CL and Wang YS.2010.Sinistral to normal faulting along the Tan-Lu Fault Zone:Evidence for geodynamic switching of the East China continental margin.The Journal of Geology,118(3):277-293
Zhu G,Jiang DZ,Zhang BL and Chen Y.2012.Destruction of the eastern North China Craton in a backarc setting:Evidence from crustal deformation kinematics.Gondwana Research,22(1):86-103
安徽省地质矿产局.1987.安徽省区域地质志.北京:地质出版社
陈宣华,王小凤,张青,陈柏林,陈正乐,Harrison TM,Yin A.2000.郯庐断裂带形成演化的年代学研究.长春科技大学学报,30(3):215-220
葛宁洁,周导之.1993.安徽肥东群变质岩系的同位素地质定年.安徽地质,3(3):22-25
康涛,刘晓燕,王娟,聂峰,石永红.2013.郯庐断裂东侧肥东地块变质属性及年代学研究.岩石学报,29(9):3142-3158
李曙光,刘德良,陈移之,王松山,裘冀,胡世玲,桑海清.1993.中国中部蓝片岩的形成时代.地质科学,28(1):21-27
聂峰,石永红,王娟,曹晟,石永红.2014.郯庐断裂带(安徽段)内磁铁石榴角闪岩的形成条件、年代学及构造归属的探究.岩石学报,30(6):1718-1730
石永红,朱光,王道轩.2009.郯庐断裂带张八岭隆起南段肥东群石榴角闪岩变质P-T演化史对其构造属性的制约.岩石学报,25(12):3335-3345
王微,宋传中,李加好,任升莲,张妍,刘欢,杨帆.2015.郯庐断裂带肥东段剪切活动锆石U-Pb测年.地质科学,50(3):800-809
吴元保,郑永飞.2004.锆石成因矿物学研究及其对U-Pb年龄解释的制约.科学通报.49(16):1589-1604
朱光,王勇生,牛漫兰,刘国生,谢成龙.2004.郯庐断裂带的同造山运动.地学前缘,11(3):169-182
朱光,张力,谢成龙,牛漫兰,王勇生.2009.郯庐断裂带构造演化的同位素年代学制约.地质科学,44(4):1327-1342