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1 GeologicalScienceandTechnologyInformation Vol.36 No.2 Mar doi: /j.cnki.dzkq ,,,. : U-Pb [J].,2017,36(2):1-12. : U-Pb 1, 2, 1, 1, 1 (1., ;2. ( ), ) :, SiO 2,Na 2O CaO TiO 2 ;, Eu U-Pb 1000~700, 2500~1800 Ma2, -, 2500 Ma,2, 437~435 Ma,,, : ; ; ;U-Pb :P :A : (2017) ,, U-Pb,,, [1-8] [9] 1, [10] ;, -, [11] - ; [20],,, [12], ;,,,, [13] ; U-Pb [21],,, [14] ;, U-Pb -, [22] -,, -, ( 1) [15-19] : : : (DD ) : (1988 ),,, @qq.com : (1969 ),,, BZYang@cug.edu.cn

3 2 : U-Pb 3 3 PM02 Fig.3 SedimentaryinterlayersandthesampleslocationsofPM02sectioninKepingtageFormation NIST %, (CaO)=0.35% ~2.10% ( (CaO), 6.48%), (K 2O)=0.63% ~ s, 10s, 2s, 2.56%, 1.11%~7.40% 60s (Fe 2O 3+MgO) 5.19%, ICPMSDataCal [24] 3.28%, 02-9 Al 2O 3 CaO K 2O ( 17.45%) ( %), (SiO 2 ) 67.28% ~92.58% ( 79.43%) 1 (Fe 2O 3 )=0.58%~1.83%, (MgO)=0.42%~ ( 4-a), 4 [25]; [26] (a) (b) Fig.4 Chondrite-normalized(a)andUCC(uppercontinentcrust)-normalized(b)REEpaternsofsandstoneinKepingtageFormation

4 Table1 1 MjorandtraceelementsdateofsandstonefromtheKepingtageFormation SiO Al2O TiO Fe2O FeO CaO MgO K2O Na2O MnO P2O La Ce Pr Nd Sm Eu Gd Tb Dy Ho Er Tm Yb Lu Th Sc Co Cr La/Sc La/Y Th/Sc Sc/Cr : %; 10-6, (LREE) (HREE) (LREE/HREE=1.14 ~13.16),Ce ( REE) ( ),, ;, -, ( ), ( 2), Th/U [27] 0.06~4.69( Tw10-2 Tw62-45 Tw62-22 ( 4-b), ) 0.1,, Ce TW10, U-Pb 3.3 U-Pb 521 Ma, 2400~500Ma, 2 3, 1000~700 Ma,2400~1800 Ma 80 U-Pb ( 5) ( 7-a); TW32, U-Pb, 435Ma, 2500~400Ma, 2 (>15%),3, 1000~700,2500~1800 Ma ( 7-b); TW62, U-Pb ( 6), 437Ma, 1800~400Ma, 2,,, 1000~700 Ma,2300~ -, 50~150μm, 1700 Ma( 7-c)

5 2 : U-Pb 5 Fig.5 5 U-Pb U-PbConcordiaofzirconsinsandstoneofKepingtageFormation Th/U 6 Fig.6 CLimagesofdetritalzirconsofthesandstoneinKepingtageFormation 2 U-Pb Table2 ZirconU-Pbage-datingofsandstonesinKepingtageFormation /Ma 207 Pb/ 206 Pb 1σ 207 Pb/ 235 U 1σ 206 Pb/ 238 U 1σ 207 Pb/ 206 Pb 1σ 207 Pb/ 235 U 1σ 206 Pb/ 238 U 1σ

6 Th/U /Ma 207 Pb/ 206 Pb 1σ 207 Pb/ 235 U 1σ 206 Pb/ 238 U 1σ 207 Pb/ 206 Pb 1σ 207 Pb/ 235 U 1σ 206 Pb/ 238 U 1σ

7 2 : U-Pb 7 2 Th/U /Ma 207 Pb/ 206 Pb 1σ 207 Pb/ 235 U 1σ 206 Pb/ 238 U 1σ 207 Pb/ 206 Pb 1σ 207 Pb/ 235 U 1σ 206 Pb/ 238 U 1σ

8 Th/U /Ma 207 Pb/ 206 Pb 1σ 207 Pb/ 235 U 1σ 206 Pb/ 238 U 1σ 207 Pb/ 206 Pb 1σ 207 Pb/ 235 U 1σ 206 Pb/ 238 U 1σ

9 2 : U-Pb 9 2 Th/U /Ma 207 Pb/ 206 Pb 1σ 207 Pb/ 235 U 1σ 206 Pb/ 238 U 1σ 207 Pb/ 206 Pb 1σ 207 Pb/ 235 U 1σ 206 Pb/ 238 U 1σ U-Pb Fig.7 ColumngraphforzirconagesdistributionofKepingtageFormation % ) (TiO 2 )(0.15%~0.55%, 0.40%),, U-Pb (TiO 2 )- (Fe 2O 3+MgO) ( 8- a) K 2O/Na 2O- (SiO 2 ) ( 8-b) [28-29], (REE) [30] ;,, ( REE Th Sc Cr Ni ),, La/Sc 2.76~9.29, [31-33] ; ( ) 5.32;La/Y 0.92~2.18, 1.61;Th/Sc 0.67~1.90, 1.10; ( 8-c), 4.2,, U-Pb [34] 2, 1000~700,2500~, Fe 2O 3+MgO TiO 2 Al 2O 3 SiO Ma, -, K 2O/Na 2O Al 2O 3 /(Na 2O+CaO), (SiO 2 ),Na 2O CaO TiO 2 U-Pb 2500 Ma (Tw10 (SiO 2 )(67.28%~92.58%, 7,Tw32 8,Tw62 3 ) 79.43%), (Na 2O)(0.28%~1.92%, 1.31%) (CaO)(0.35%~2.10%, 0.86%, Sc/Cr 0.17~0.28, 0.22 La/Y-Sc/Cr,

10 A. ;B. ;C. ;D. (a b [32];c [17]) Fig.8 Discriminatiomdiagramsofsandstonefrom KepingtageFormationfortectonicseting U-Pb 2600 Ma, TIMS 2565 Ma [28-29] 2500~1800 Ma [(2492±19) (1836±25)Ma] [47-49] [(1943±6)Ma], -, -,Carrola [35] (1962±27)Ma [50] (2100~ 1800 Ma) [36] [9-10] 1000~700 Ma U-Pb [(807±21) 20 Ma],,, [(755±15)Ma] A ( [(815±57)Ma] ( U-Pb 8), 753 Ma) [ SHRIMP,3 U-Pb (757.4±6.2)Ma], ( 7), [37-41],, Rodinia, [42], Rodinia 850~750 Ma, 5,, (1),, 2 [(435±8),(437±11)Ma], (2) 1000, ~700 Ma 2500~1800 Ma, 2500 Ma, [(430.6±1.6)Ma],, (3), [(419.2±3.1),(418±2.7) Ma] [43-44] :, [1],,. [45-46],, [M]. :,1991:1-29.

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12 [42],,,. Newinsightsfromgeochemistry,geochronologyandpetrology [J].,2010,31(1): [43],,, [J].,2006,25 [47],,,. [J]. (6): [44],,,. [48],,,, [J].,2013, : SHRIMP LA-ICP-MS [J]. 32(2/3): [45] Wang B,Shu L,Faure M,etal.Paleozoictectonicsofthe southernchinesetianshan:insightsfrom structural,chrono- logicalandgeochemicalstudiesofthe Heiyingshan ophiolitic 104. [46]ChenXJ,ShuLs,Santosh M.LatePaleozoicpost-colisional magmatismintheeastern Tianshan Belt,NorthwestChina:,2009,28(12): :,2007,37(2): [49],,. : [J].,2002,21(2): [50]CarrolaA R,Graham SA,ChangEZ,etal.Sinianthrough Permiantectonostratigraphic evolution ofthe northwestern Tarim Basin,China[J].GeologicalSocietyofAmericaMemoir, 2001,194: ProvenanceAnalysisfrom EarlySilurianKepingtage FormationinKepingArea,Xinjiang: Constraintsfrom GeochemicalCharacteristicsand ZirconU-PbGeochronology LiLulu 1,YangBaozhong 2,YinYonghui 1,LiuLonglong 1,WangBing 1 (1.No.7GoldGeologicalPartyofPAP,YantaiShandong264000,China; 2.SchoolofEarthSciences,ChinaUniversityofGeosciences(Wuhan),Wuhan430074,China) melange(nw China)[J].Tectonophysics,2011,497(1/4):85- ofbimodalvolcanicrocks[j].lithos,2011,127(3/4):581- Abstract:Takinggray-greensandstoneofKepingtageFormationforresearchobjects,systematicgeochem- icalandisotopicgeochronologicalanalysesareapplied.resultssuggestthattherearehighcontentofsio 2 andlowcontentofna 2O,CaOandTiO 2. LREE> HREE,abnormityofEuisnegative.U-Pbagesof zirconsconcentratein Maand Ma,whichmaycorrespondingtotectonicuplifting eventsoccurredduringlateproterozoicnanhuatoqingbaikouperiodand magmaticemplacementcouple withintensetectonicmovementsduringpaleoproterozoic.severalu-pbagesofzirconsover2500ma,may berelatedtoremeltingofarcheozoicstrata.twou-pbagesofzirconsbetween437 Mato435 Mamaybe relatedtomagmationresultedfromsouthwardsubductionofthesouth Tianshan Ocean.Analysesshow thatthekepingareawassituatedonapassivecontinentalmarginduringearlysilurian.sedimentaryrocks aremainlysourcedfrom Pre-Cambrianbasementrocksin Tabeiarea,mixing withseveralgranitzircons from EarlySilurian. Keywords:KepingtageFormation;geochemistry;provenanceregion;U-Pbdating

, 3.1 PM303, 10(2)( 5, 5 ), 1 w (SiO 2 ) 68% ~89%, 2( 1, 1) (Al 2O 3,Fe 2O 3,MnO) (MgO,K 2O, Na 2O),w(TiO 2 ) w (SiO 2 ) ;,w (TiO 2 ) 0.31%

, 3.1 PM303, 10(2)( 5, 5 ), 1 w (SiO 2 ) 68% ~89%, 2( 1, 1) (Al 2O 3,Fe 2O 3,MnO) (MgO,K 2O, Na 2O),w(TiO 2 ) w (SiO 2 ) ;,w (TiO 2 ) 0.31% 36 3 2017 5 GeologicalScienceandTechnologyInformation Vol.36 No.3 May 2017 doi:10.19509/j.cnki.dzkq.2017.0302,,,. [J].,2017,36(3): 7-17. 1, 1, 1, 2, 1 3 (1., 264004;2. ( ), 430074; 3., 710000) :, (Al 2O