Autochthonous Upper Permian (Midian) Carbonates In
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TurkishJournalofEarthSciences (TurkishJ.EarthSci.),Vol.13, 2004,pp.215-229. Copyright©TÜB‹TAK AutochthonousUpperPermian(Midian)Carbonates intheWesternSakaryaCompositeTerrane,GeyveArea, Turkey:PreliminaryData NECAT‹TURHAN1,CENG‹ZOKUYUCU1 &M.CEMALGÖNCÜO⁄LU2 1 DepartmentofGeologicalResearch,GeneralDirectorateofMineralResearchandExploration(MTA), TR-06520Ankara,Turkey 2 DepartmentofGeologicalEngineering,MiddleEastTechnicalUniversity, TR-06531Ankara,Turkey(e-mail:[email protected]) Abstract: Permianlimestonesoccurwidelywithintheclasticunitsofthe“KarakayaComplex”andareinterpreted asallochthonousbodiesorolistoliths.IntheKadirlerareatothesouthofGeyve,however,UpperPermian(Midian) quartzsandstonesandcarbonateswitharichforaminiferfaunadisconformablyoverlieacrystallinebasement complex.Thisbasementcomplexcomprisesmetaclasticrocks,recrystallisedlimestones,metacherts,and metadiabases,andisintrudedbygranodiorites.Theoverlyingbasalconglomeratesandquartziticsandstonesare dominatedbypebblesfromthebasementcomplexandarefollowedupwardbymedium-tothick-bedded dolomites,dolomiticlimestonesandlimestones. TheforaminiferalassemblagewithNeoschwagerinahaydeni DutkevitchandKhabakov,Neoschwagerina ex.gr. ventricosa Skinner, Charliellarossae Alt›nerandÖzkan-Alt›ner, Hemigordiopsisrenzi Reichel, Yabeina sp., Pseudokahlerina sp.andKahlerina sp.inthesecarbonatesisindicativeofdepositioninashelf-lagoonduringthe MidianstageoftheLatePermian. ThisnewfindingconstitutesfurthersupportformodelsthatsuggestacompositecharacterfortheSakarya Terrane,andthatthe“Karakayabasin”inNWAnatoliaopenedaboveaVariscan-consolidatedcrustalbasementand itsPermianplatform,whencethelimestoneolistolithsofthe“KarakayaComplex”weremainlyderived.Moreover, theMidiantransgressionandtheforaminiferalassemblageinthestudiedsuccessionsaretypicalfeaturesofthe northernTauride-AnatolidePlatform,indicatingthattheSakaryaCompositeTerranewasattachedtothelatter priortotheopeningofthe‹zmir-AnkarabranchofNeotethys. KeyWords: KarakayaComplex,basement,autochthon,limestone,UpperPermian SakaryaKompozitBirli¤iBat›s›nda(Geyve,Türkiye)OtoktonÜstPermiyen (Midiyen)Karbonatlar›:ÖnBulgular Özet: Permiyenyafll›kireçtafllar›“KarakayaKompleksi”nink›r›nt›l›birimleriiçindeyayg›nolarakgözlenirlerve alloktonkütlelerveyaolistolitlerolarakyorumlan›rlar.Ancak,Geyve’ningüneyinde,Kadirleryöresinde foraminifercezenginkumtafllar›vekireçtafllar›metamorfikbirtemelüzerindeuyumsuzolarakyeralmaktad›r. Metamorfiktemel;metak›r›nt›l›kayalar,rekristalizekireçtafllar›,metaçörtlervemetadiyabazlardanoluflurvebir granodiyoritkütlesitaraf›ndankesilmifltir.Butemelüzerindeyeralantabankonglomeras›vekuvarsitikkumtafllar› metamorfiktemeldentüremeçak›llariçerirveüstedo¤ruorta-kal›ntabakal›dolomitler,dolomitikkireçtafllar›ve kireçtafllar›nageçifllidir. Karbonatkayalar›n›nkapsad›¤›foraminifertoplulu¤u( Neoschwagerinahaydeni DutkevitchandKhabakov, Neoschwagerina ex.gr. ventricosa Skinner, Charliellarossae Alt›nerandÖzkan-Alt›ner, Hemigordiopsisrenzi Reichel,Yabeina sp.,Pseudokahlerina sp.ve Kahlerina sp.),bubiriminMidiyens›ras›ndas›¤denizelbirortamda (flelflagünü)çökeldi¤inigösterir. Bubulgu,“SakaryaTektonikBirli¤inin”kompozitnitelikteoldu¤u,Karakayabaseni'ninPermiyenplatform karbonatlar›ileörtülübirVariskenk›tasalkabukparças›üzerindeaç›ld›¤›veiçindeyeralankireçtafl›olistolitlerinin buplatformdankaynakland›¤›hususundakigörüflleridesteklemektedir.‹ncelenenalandakibelirginMidiyen transgresyonuveforaminifertoplulu¤uToroslar›nkuzeykesimiileözdeflnitelikteolup,SakaryaveTorid-Anatolid tektonikbirliklerininNeotetis’in‹zmir-Ankarakoluaç›lanade¤inbitiflikolduklar›naiflaretetmektedir. AnahtarSözcükler:KarakayaKompleksi,otokton,temel,kireçtafl›,ÜstPermiyen 215 AUTOCHTHONOUSMIDIANCARBONATESINTHEWESTERNSAKARYACOMPOSITETERRANE Introduction Mesozoicage”.Withsomedifferencesinthetimingofthe Oneofthemostdebatedissuesconcerningthegeology events,fiengör etal. (1984),Göncüo¤lu etal. (1987), ofNWTurkeyisthegeologicalevolutionoftheKarakaya Okayetal. (1991)and,Y›lmaz etal. (1995)havenoted ComplexinNWAnatolia.Theterm“Karakaya”was thatthebasementrocksarecharacterisedbyaVariscan- initiallyintroducedbyBingöl(1968)asthe“Karakaya consolidatedcrystallinecomplex(Sakaryabasement)and Series”,foraslightlymetamorphicsuccessionat itsUpperPalaeozoiccarbonatecover.Thelatter KarakayaHilltothesouthofBeyobas›Villageinthe representsthenorthernmarginoftheGondwanan Edremitarea,NWAnatolia.Sincethen,thenamehas Tauride-Anatolideunit,uponwhichtheTriassicKarakaya beenappliedbydifferentauthorstoawiderangeof clasticrocksformedinamarginalbasin,abovethe rockunitsindifferentpartsofnorthwesternand southward-subductingPalaeotethyanoceaniclithosphere northernAnatolia(Figure1a).Tekeli(1981)proposed (Figure2a).Okayetal. (1996)andLeven&Okay(1996) thatthispartlymetamorphicandextremelytectonised proposedacompletelydifferentscenario,inwhichthe assemblagerepresentstheremnantsoftheLate SakaryabasementwasattachedtotheLaurasianmargin Palaeozoic–EarlyMesozoicPalaeotethysoffiengör nexttothe‹stanbulUnit.AlltheTriassicKarakayaunits (1979)(forabriefreviewseeOkayetal. 1996;Okay& (Nilüfer:Early–MiddleTriassicfore-arc,Çal:islandarcor Göncüo¤lu2002). matureseamountwithPermo–Triassiccarbonate platform,HodulandOrhanlar:Middle–LateTriassic Thecontroversyregardingtheoverallgeodynamic accretionarycomplexes,Denizgören:Triassicophiolites) evolutionalsoincludesthecrystalline“basementrocks”of wereformedduringtheclosureofthePalaeotethys.The theKarakayaComplex,theirpalaeogeographiclocation, Permiancarbonates(includingtheEzineUnit)were ageandcontactrelationswiththePermo–Triassicnon- derivedfromaTauride-Anatolide-typecontinentalsliver, to-slightlymetamorphicsedimentaryandvolcanicrocks. whichwasriftedfromthelatterbyback-arcspreading Tekeli(1981)’soriginalsuggestionwasthatthe (Figure2b)resultingintheopeningofthe‹zmir-Ankara “metamorphicsatthebase”were“coevalwiththe branchofNeotethys. Karakayamélangeand,hence,ofLate Palaeozoic–Early A BLACK SEA N B N Bahaiye ÝSTANBUL (Esenköy) EXPLANATIONS ANKARA Muttalip Göçük D. post-Triassic cover Study Area (Figure 1b) ÝZMÝR 0 100 km Sakarya Composite Terrane Pazarkaya T. Karaoluk T. recrystallized limestone and Alýplar Karþýköy pillow basalts Koca D. Asarkaya T. arkosic sandstones Triassic Yukarýyayla U. Permian- Derbent Limestone Çinetaþý T. Canbazkaya Formation Figure 3a U. Permian Sindir D. granodiorite Cumalý black recrystallized limestones 0 500 1000 m Kayýplar Figure 3b Kabaklý D. (Aragat) Kadirler pre-Permian micaschists, metacherts, metarhyolites (undifferentiated) normal reverse contact foliation bedding a fault fault Figure1. (a)DistributionoftheSakaryaCompositeTerraneinNWAnatoliaand (b) thegeologicalmapofthestudyareawithandthelocationsof thestudiedsections. 216 N.TURHANET AL. a Early Triassic b L. Permian te Moesia li Ýstanbul Zone i o h p V Stranja o V Sakarya Zone V Zone n e V Karakaya r ö Rift g V (future Neotethyan z i n V Vardar ocean) V PALEO-TETHYS De V Volcanic arc V V V V Unit V V Nilüfer V back-arc rifting K V IDE BLOC V Ýzmir-Ankara Rift AUR Pindos V - T IDE TOL Okay et al. 1991 ANA Okay et al. 1996 c NS Late Permian EURASIA subduction GONDWANA jamming Çanðaldað arc or equivalent carbonate platforms on Gondwanan continental slivers MODEL 1 site of new subduction zone MODEL 2 Karakaya Complex Karakaya Complex Early Triasic ophiolite formation ophiolite formation rifting (i.e., Chios, Karaburun) Pickett & Robertson 1996 d Tauride-Anatolide Platform Late Permian Future Sakarya Microcontinent deposition of the platform carbonates Paleotethys Hercynian consolidated basement opening of Karakaya Early Triassic Basin s.s. deposition of continental clastics closure of Paleotethys rifting along KBB uplift Göncüoðlu et al. 2000a e South North SOUTHERN BIOFACIES NORTHERN BIOFACIES BELT BELT BEYÞEHÝR - AKSEKÝ - HADIM HIGH DEPOSITIONAL BASEMENT OF FUTURE AREA OF SAKARYA CONTINENT ANTALYA or GEYÝK DAÐI ALADAÐ BOLKAR DAÐI UPPER PERMIAN ALANYA ? BLOCKS OF (Hercynian Orogen) KARAKAYA UNITS Permian ? PRE- ? LATE PERMIAN ? ? ? Altýner et al. 2000 ORDOVICIAN DEVONIAN CARBONIFEROUS LOWER PERMIAN UPPER PERMIAN f Çal Unit SNOrhanlar Greywacke Nilüfer oceanic plateau Laurasian margin (a) Mid Triassic Okay 2000 Figure2. CartoonsofpreviouslysuggestedgeodynamicmodelsfortheevolutionoftheKarakaya units.Forthedetailsconcerningthecartoons,seetext. 217 AUTOCHTHONOUSMIDIANCARBONATESINTHEWESTERNSAKARYACOMPOSITETERRANE Pickett&Robertson(1996)’smodelinvolvesthe underlainthePermo–Carboniferouslimestonesinthe closureofthePalaeotethysbysouthandnorthward SakaryaZone”asclearlyformulatedbyOkay(2000). subduction(Figure2c).TheyconsideredtheKarakaya Inthisstudy,wewillfirstbrieflysummarisethe ComplexasaPalaeotethyanaccretionarycomplexwith previousdataonthebasementrocksoftheKarakayaunit Triassicophiolites(DenizgörenOphiolite),seamounts andtheirrelationswithPermianlimestones.Fieldand (NilüferUnit),trenchsequences(OrtaobaUnit)abyssal- palaeontologicaldatafromtheGeyveareawillthenbe plaindeposits(KalabakUnit)andPermiancarbonate presentedandtheevolutionofthe“KarakayaComplex” platformsonGondwanancontinentalsliverswithintra- discussed. platformrifts(ÇalUnit). Göncüo¤luetal. (1997,2000c)pointedoutthatthe pre-Liassic“KarakayaComplex”withintheAlpineSakarya ReviewofPreviousInterpretations unitinnorthernTurkeyactuallyincludesremnantsof AccordingtotheoriginaldescriptionofBingöl(1968), Variscanbasement,aTriassicrift-complexformedabove theKarakayaunitincludesinitstypelocalityquartzites, itsPermiancover,aswellasthrustslicesofthe feldspathicsandstone,metaspiliteandmetamorphosed Palaeotethyanorogeniccomplex(Figure2d).Itwasalso spiliticbasaltsthatdisconformablyoverliethecrystalline