3. Okay, A.I., İşintek, İ., Altıner, D., Özkan-Altıner, S., Okay, N., 2012, An olistostrome

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Tectonophysics568–569(2012)282–295
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Tectonophysics
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An olistostrome–mélange belt formed along a suture: Bornova Flysch zone,
western Turkey
Aral I. Okay a,⁎, İsmail İşintek b, Demir Altıner c, Sevinç Özkan-Altıner c, Nilgün Okay d
aEurasiaInstituteofEarthSciencesandDepartmentofGeology,FacultyofMines,IstanbulTechnicalUniversity,Maslak34469,Istanbul,Turkey
bDokuzEylülUniversity,FacultyofEngineering,DepartmentofGeology,Tınaztepe,Buca35160İzmir,Turkey
cMiddleEastTechnicalUniversity(METU),DepartmentofGeologicalEngineering,TR-06531Ankara
dDepartmentofGeology,FacultyofMines,IstanbulTechnicalUniversity,Maslak34469,Istanbul,Turkey
a r t i c l e i n f o a b s t r a c t
Articlehistory: TheBornovaFlyschZone(BFZ)inwesternTurkeyisaregionalolistostrome–mélangebeltlocatedbetween
Received2March2011 theİzmir–AnkaraTethyansutureinnorthwestandtheMenderesMassifinthesoutheast.TheBFZconsists
Receivedinrevisedform31December2011 mostlyoftectonizedgravitymassflows.TheblocksareMesozoiclimestoneandophiolite,whichareenclosed
Accepted7January2012 inCretaceous–Paleoceneshearedsandstoneandshale.Thelimestoneblocksareoftwotypes.Thefirsttype
Availableonline31January2012
consistsofLateTriassictoCretaceousshallowmarinecarbonates.ThesecondtypehasanUpperTriassicshal-
lowmarinesectionoverlainbyJurassictoCretaceouspelagiclimestones.Asemi-intactpartoftheplatform
Keywords:
occursintheKaraburunpeninsulaandontheislandofChios.TheophioliticblocksintheBFZincludeultra-
Olistostrome
Mélange maficrock,gabbro,basaltandradiolarianchertofMiddleTriassictoCretaceousinage.Theformationofthe
Turkey BFZoverlapswiththeCretaceoussubductionandHP/LTmetamorphismofthenorthernpassivecontinental
BornovaFlyschZone marginoftheAnatolide–TaurideBlock.Thissubductionzonewasboundedinthewestbyastrike–sliptear
Stratigraphy fault. The BFZ formed in anarrow basin between this tear fault and theTethyan ocean.The mass flows
Mesozoic camefromthesoutheastfromtheoverridingophioliteandaccretionarycomplex,andfromthenorthwest
fromtheupliftedsegmentsoftheplatformmargin.ThismodelprovidesanexplanationaswhytheBFZis
unmetamorphosed,whereastheequivalentstrataintheMenderesMassifweremetamorphosedatdepths
ofover20km.Italsoexplainstheprominenceofgravity flowsandthesouthwardyoungingintheBFZ,
andfortheapparentlyanomalousobservationthat,althoughtheTethyanoceanlaytothenorthwest,the
ophioliticblocksaremorecommononthesoutheasternpartoftheBFZ.Regionsawayfromthetearfault,
suchastheKaraburunpeninsula,wereleastaffectedbysubsidenceanddeformationduringtheCretaceous
andPaleocene.
©2012ElsevierB.V.Allrightsreserved.
1.Introduction environments, even passive continental margins, have been sug-
gested as regions of mélange and olistostrome formation (cf. Festa
Definition of mélanges and olistostromes and their distinction etal.,2010). Here,wedescribearegionalbeltofolistostromesand
havebeensubjectofdiscussions(e.g.,Festaetal.,2010;Hsü,1968, mélanges in northwest Turkey, provide new biostratigraphic data
1974; Raymond, 1984; Şengör, 2003; Silver and Beutner, 1980). fromtheblocks,andinterprettheirorigins.Wearguethattheolistos-
Bothrockbodiesconsistofblocksinafragmentedfinergrainedma- tromesandmélangesintheBornovaFlyschZonehavebeendeposit-
trixandarecharacterizedbyalackofstratalcontinuity.Acommon ed and deformed in a basin adjacent to a southward propagating
view, adopted here, is that olistostromes are sedimentary deposits strike–sliptearfault,whichconstitutedthenorthwesternboundary
produced by gravity mass flows, whereas sedimentary processes, ofacontinentalsubductionzone.
faulting and tectonic shearing have a role in the formation of TheBornovaFlyschZoneislocatedinwesternTurkeysoutheastof
mélanges. Especially the presence of a shear fabric in the matrix is theTethyanİzmir–Ankarasuture(Fig.1).Itisaca.60kmwideand
commonlytaken as a characteristic feature of a mélange. The most ca.225kmlongbeltofmélange–olistostromeconsistingofdeformed
commontectonicenvironmentfortheformationofthesefragmented Maastrichtian–Paleocene greywacke and shale with Mesozoic lime-
and mixed rock bodies are subduction zones, but other tectonic stone and ophiolite blocks. The northwestern parts of the Bornova
Flysch Zone are dominated by Mesozoic limestone blocks and the
southeastern side by ophiolitic blocks (Fig. 2). The ophiolitic belt
⁎ Correspondingauthor.Tel.:[phone];fax:[phone].
wasincludedbyBrinkmann(1966)andBrinkmannetal.(1972)in
E-mailaddresses:[email protected](A.I.Okay),[email protected](İ.İşintek),
[email protected](D.Altıner),[email protected](S.Özkan-Altıner), the İzmir–Ankara Zone, whereas the carbonate-dominated north-
[email protected](N.Okay). western part was regarded as part of the Pontides. In 1993 it was
0040-1951/$–seefrontmatter©2012ElsevierB.V.Allrightsreserved.
doi:10.1016/j.tecto.2012.01.007
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A.I.Okayetal./Tectonophysics568–569(2012)282–295 283
Fig.1.TectonicmapoftheAegeanregionshowingthesettingoftheBornovaFlyschZone.
shown that this sedimentary belt extending from Balıkesir south- The orientation of the fabric (minor faults, shear zones, fracture
west to the Karaburun Peninsula, attributed previously to the cleavage,cleavage,orientationoftheblocks,etc.)isvariablewithin
Pontides (e.g., Akyürek and Soysal, 1981; Brinkmann, 1966, 1972; anoutcropandbetweenoutcrops,andnoattemptwasmadetosys-
Brinkmannetal.,1970;Ketin,1966;ŞengörandYılmaz,1981),con- tematicallymeasuretheorientationofthefabricelements.Someof
tainstypicalTaurideMesozoicsequences,andthesedimentarybelt thefabricwasproducedduringthegravitationalflow,especiallyat
along with the ophiolitic zone was named as the Bornova Flysch thebaseoftheolistostromes(Fig.3AandC).However,shearingof
Zone(OkayandSiyako,1993;Okayetal.,1996;Moixetal.,2008). beddedsandstoneswithnoevidenceofgravitationalflow,indicates
InparticulartheTauridesequencesarecharacterizedbycarbonate semi-brittle post-depositional deformation. In many outcrops the
depositionintheMiddleTriassictoLateCretaceousinterval,where- superpositionofsedimentaryandtectonicprocessesmakesthedis-
astheSakaryaZoneofthePontideshasastronglydeformedUpper tinction between olistostromes and mélanges highly problematic.
Triassicvolcano-sedimentarybasementunconformablyoverlainby TheBornovaFlyschZoneconsistsofmélangeswithnoevidencefor
LowerJurassiccontinentalclasticrocks.Theextensiveandcoherent sedimentary processes in their genesis, olistostromes, and tecto-
MesozoicsequencesontheKaraburunPeninsulaandontheadjacent nizedolistostromes.
islandofChioshavealsoTaurideaffinities.TheBornovaFlyschZone The sandstones in the Bornova Flysch Zone are medium to
forms a peculiar mélange–olistostrome belt between the İzmir– thickly bedded, commonly laminated greywackes with a greenish
Ankara suture and the Menderes Massif, which shows Eocene re- gray, black color in fresh outcrops; they are intercalated with
gionalmetamorphism(Fig.2). greenish gray laminated shales. In weathered outcrops the sand-
stones andshales have a typical brownish yellow color. There are
2.ThematrixoftheBornovaFlyschZone no paleontological ages from the sandstone-shale matrix of the
Bornova Flysch Zone. However, some parts of the Bornova Flysch
IntheBornovaFlyschZoneblocksofvarioussizesandlithologies Zone, especially in the İzmir–Manisa region, include calcareous
are surrounded by a clastic matrix of sandstone and shale. On the shales with thin pelagic limestone intercalations. These yielded
mesoscopicscalethematrixrangesfromessentiallyundeformedto pelagicforaminiferaofMiddle-LateMaastrichtian–Danian(Kocaçay
acrudefoliationinducedbygravitationalflow(Fig.3A)totectonical- region,locality1inFig.2,Erdoğan,1990a;İşinteketal.,2007)and
ly sheared sandstones and shales with a penetrative scaly fabric Middle-Late Maastrichtian ages (Kocaçay and Spil Dağı regions,
(Fig.3B).However,eveninapparentlyundeformedmatrix,thebed- localities1and6inFig.2,Erdoğan,1990a;İşinteketal.,2007)and
ding in the sandstones cannot be traced along or across strike for nannofossilsofEarlyPaleoceneage(Işıklar,locality4inFig.2,Özer
morethan10m;shearinghasdestroyedmostsignsofthebedding. andİrtem,1982).
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284 A.I.Okayetal./Tectonophysics568–569(2012)282–295
Fig.2.GeologicalmapoftheBornovaFlyschZone(compiledfromKonak,2002;KonakandŞenel,2002).ThenumbersrefertothestratigraphicsectionsinFigs.4and5.
The youngest blocks in the Bornova Flysch Zone are usually ofsimilarsizeasthelimestoneclastsintheconglomeratearephyl-
TuronianinthenortheastandCampanianinthesouthwest.However, lite, amphibolite, quartz, red and green chert, quartzite and sand-
in one locality close to İzmir (Kocaçay, locality 1 in Figs. 2 and 4), stone(İşinteketal.,2007;Konuk,1977).
Paleoceneshallowmarinelimestoneclastsoccurinachannelfillcon- Anupperlimittotheageofthematrix,aswellastothepenetra-
glomerate(Erdoğan,1990a;İşinteketal.,2007;Konuk,1977).These tivesemi-brittledeformationoftheBornovaFlyschZoneisgivenby
are 1 to 20m across, grey, biohermal limestones with abundant theundeformedLowerEocene(Cuisian)shallowmarinelimestones,
corals,sponges,redalgae,dasycladeaalgaeandforaminifera.Forami- whichlieunconformablyoverthematrixandblocksoftheBornova
niferaandalgaefromtwelvesamplesoutoftenblocksgiveaMiddle FlyschZonenortheastofAkhisar(Fig.2,Akdeniz,1980).Hencepale-
to Late Paleocene age based on Lockhartia? sp., Miscellanea sp., ontologicaldataconstraintheageofdepositionanddeformationof
Cymopoliamayaense,Broeckellabelgica,Neomerissp.,Oreoporellacf. theclasticmatrixtoMaastrichtian–Paleocene.Thestratigraphicbase
malaviae,Acroporella?chiapasis,Zettelinaradoicicae.Theotherclasts oftheflyschisnotobservedinthemainbodyoftheBornovaFlysch
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A.I.Okayetal./Tectonophysics568–569(2012)282–295 285
Fig.3.FieldphotosoftheBornovaFlyschZone.A.crudefoliationinthedebrisflowinducedbygravitationalflow.B.Tectonicallydeformedsandstone-shalematrixwithascaly
fabric.C.Olistostromehorizonsdippingsteeplytotheleft.D.Ablockmorethan10-m-acrossintheolistostromes.
Zone,onlyintheKaraburunPeninsulaMaastrichtiansiliciclastictur- limestoneslie unconformablyoveroldercarbonatesand commonly
bidites lie stratigraphically on Campanian to Maastrichtian pelagic ontheTriassiclimestones.Withinthiscommonframeworktheblocks
limestones(seebelow). can be divided into two types, called here as the platform and
platform-margin(Figs.4and5).
3.BlocksintheBornovaFlyschZone
3.1.1.Platform-typelimestoneblocks
TheclastsintheBornovaFlyschZonerangefromgrainstoblocks
Intheplatform-typeblocks,theshallowmarinecarbonatedeposi-
measuringseveralkilometersormore.Thereisevidenceinthefield
tion continues from the Triassic into the Cretaceous with gaps in
thatthesmallerclasts,uptoaseveralmetersinsize,aresedimentary.
thestratigraphicsequence.Theseblocksarerestrictedtotheİzmir–
They occur as angular clasts in a sandy silty matrix in very poorly
ManisaregionclosetotheKaraburunpeninsulaandeastofAkhisar
sorted mass flows (Fig. 3C). The observed thickness of the mass
(localities1,3,4,5and6inFig.2,forthegeographiccoordinatesof
flowsrangesfromafewmeterstotensofmeters.Forlargerblocks,
the measured sections see Table 1 and for characteristic fossil taxa
thecontacts between theblock and the sandymatrixare generally
Fig. 6). The youngest ages from the platform carbonates of the
sheared; this is probably due to post-depositional deformation,
platform-type blocks are Cenomanian–Turonian in the Naldöken
whichwasfocusedalongsuchcontacts(Fig.3D).Althoughthereare
andKemalpaşaareas(loc.3and5inFig.2)andTuronian–Coniacian
sandstoneblocks,derivedfromthefragmentationofthecompetent
in the Işıklar area (loc. 4, Fig. 4, Özer and İrtem, 1982; Erdoğan,
sandstonebeds,mostblocksintheBornovaFlyschZoneareexotic,
1990a;İşinteketal.,2007).Pelagicredmarlsandmicriticlimestones
and are essentially of two types; limestone and ophiolite; these
of LateCretaceous age lie unconformably overJurassic–Lower Creta-
typesaregenerallynotmixed;thelimestoneblocksaredominantin
ceouslimestonesordirectlyovertheTriassiccarbonates.Thebaseof
thenorthwestandtheophioliticblocksinthesoutheast.Theageof
the red pelagic limestones is Coniacian (?)–Early Campanian in the
the blocks range from Middle Triassic to Late Cretaceous, and are
platform-type blocks and the youngest ages are Early Maastrichtian
olderthanthematrix.
(PoissonandŞahinci,1988;Erdoğan,1990a;Figs.4and6).
3.1.Limestoneblocks
3.1.2.Platform-margintypelimestoneblocks
By far the most common clasts in the Bornova Flysch Zone are Intheplatform-margin-typeblockstheJurassic–LowerCretaceous
Mesozoiclimestones,whichrangeinsizefromafewcentimetersto ischaracterizedbyacondensedpelagicmarinesequenceofpelagic
severaltensofkilometers.Inthekilometer-sizeblocks,itisdifficult limestone and radiolarian chert with a total thickness of less than
toascertainwhetheroneisdealingwithasingleblockorseveraljux- 50m(Fig.5).TheyareknownonlyfromnorthofManisa.Thecon-
taposed blocks. Detailed biostratigraphic studies have been carried densed series usually starts with Middle or Upper Jurassic pelagic
out in a large number of limestoneblocks(Erdoğan, 1990a;İşintek limestones(Fig.6),whichrestontheUpperTriassicshallowmarine
etal.,2007;OkayandAltıner,2007;OkayandSiyako,1993;Poisson carbonates. In the Urbut section, the Jurassic–Lower Cretaceous se-
and Şahinci, 1988; Şahinci, 1976). Their common stratigraphic fea- quence is only 19 meters thick but includes Tithonian, Berriasian,
turesare:a)aLateTriassictoCretaceousagerange,b)LateTriassic Valanginian and Albian stages as determined by the foraminifera
is represented by thickly bedded to massive shallow marine lime- fauna(Fig.5,OkayandAltıner,2007).Theabsenceofsomeinterven-
stones.VolumetricallytheUpperTriassiclimestonesmakeupmore ingLowerCretaceousstages(e.g.,Hauterivian,BarremianandAptian)
than 80% of the carbonate blocks, c) Cretaceous red pelagic couldrepresentarealgaporcouldbeduetolackofsampling.
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286 A.I.Okayetal./Tectonophysics568–569(2012)282–295
Fig.4.StratigraphyoftheKaraburunpeninsulaandplatform-typeblocksfromtheBornovaFlyschZone.Datasources:Karaburun(Erdoğanetal.,1990;İşintek,2002),1.Kocaçay
(Erdoğan,1990a;İşinteketal.,2007),2.Eğridere(İşinteketal.,2007),3.Naldöken(Erdoğan,1990a;İşinteketal.,2007),4.Işıklar(Özerandİrtem,1982),5.Kemalpaşa(Poissonand
Şahinci,1988),6.SpilDağı(Erdoğan,1990a).ThenumbersarekeyedtothemapinFig.2.ForgeographiccoordinatesofthemeasuredsectionsseeTable1.
The Triassic–Lower Cretaceous carbonates are unconformably partofthe Bornova FlyschZone.The oldestradiolaria agesfrom the
overlainbyredpelagiclimestones.IntheUrbutsection,Turonianpe- cherts are Middle Triassic (Ladinian–Carnian) and the ages range
lagic limestones contain several meters large Upper Triassic lime- up to the Cenomanian with an apparent gap from Late Triassic
stone olistoliths, showing that the disintegration of the carbonate (Norian) to Early Jurassic (Fig. 7, Tekin and Göncüoğlu, 2007,
depositionalsystemstartedalreadyintheTuronianinthenortheast, 2009).Thegeochemistryoftheassociatedbasaltsinthemélangeis
whereasplatformcarbonatedepositionwascontinuingatthistime indicativeforthemid-ocean-ridgeandsupra-subductionzonetype
inthesouthwest(OkayandAltıner,2007).Intheplatform-margin- tholeiites, and ocean island type alkali basalts (Aldanmaz et al.,
type blocks, the age of the red pelagic limestones is also older 2008).Thestratigraphicandgeochemicalfeaturesoftheophiolite
(Aptian-CenomaniantoTuronian,Fig.6)thanthatintheplatform- and radiolarite blocks suggest that they were derived from a
type blocks (Coniacian-Maastrichtian) again indicating a general sediment-starvedoceanicaccretionarycomplex.Agesfromtheradi-
diachronous collapse of the carbonate depositional system with olarianchertsindicatethattheİzmir–Ankaraoceanhadanagerange
younging towards the southwest.Thisalso implies thatthe age of fromatleastMiddleTriassictoCretaceous(TekinandGöncüoğlu,
theflyschmatrixyoungsfromnortheasttosouthwest. 2007).
3.2.Ophioliteandradiolarianchertblocks 4.KaraburunandChiossequence
TheophioliticblocksintheBornovaFlyschZoneincludepartially The thick and extensive Paleozoic-Mesozoic sequences in the
ortotallyserpentinitizedperidotite,gabbro,diabaseandbasalt.They KaraburunPeninsulaandontheadjacentislandofChiosdifferfrom
rangeinsizefromafewmeterstoseveralkilometers.Theproportion theblocksintheBornovaFlyschZonemainlybytheirsizeandtheir
oftheophioliticblocksincreasessoutheastwardsattheexpenseof relativestratigraphiccoherence.TheKaraburun–Chiosseriescanbe
limestone blocks, and in Sındırgı region the Bornova Flysch Zone stratigraphically divided into three parts; the lowest part is a Late
consist in places of an ophiolitic mélange (Tekin and Göncüoğlu, Paleozoic mélange withSilurian,DevonianandCarboniferousblocks
2007,2009;Uz,1990). (ÇakmakoğluandBilgin,2006;Grovesetal.,2003;Kozur,1997,1998;
Redradiolarianribboncherts,oftenintercalatedwithmudstones RobertsonandPickett,2000;Stampflietal.,2003;Zanchietal.,2003),
andshales,andassociatedwithbasaltsarecommoninthesoutheastern which is unconformably overlain by an over 2000m thick,
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A.I.Okayetal./Tectonophysics568–569(2012)282–295 287
NN NN NN NN heterogeneous,LowertoMiddleTriassicsequenceofpelagiccherty
1132 3642 1034 7500 limestone, radiolarian chert, mafic lava, tuff, sandstone and mud-
71 51 63 75
5151 6868 1919 3535 stone (Besenecker et al., 1968; Erdoğan et al., 1990; Jacobshagen,
52 22 33 33
–4–4 –4–4 –4–4 –4–4 1972). This series is overlain by a 2320-m-thick shallow-marine,
93E87E 96E75E 81E53E 75E25E massive to thickly bedded sequence of limestone and dolomite,
71 80 28 14
1719 3334 5150 6969 Middle Triassic to Cretaceous in age (Brinkmann et al., 1972;
55 55 55 55
00 00 00 00 Erdoğan et al., 1990; İşintek, 2002; Masse & İşintek, 2000). The
B:F: B:F: B:F: B:F:
platform-typeblocksintheBornovaFlyschZonearederivedfromthis
part of the sequence. It is probable that pre-Middle Triassic parts of
ht. theKaraburun–ChiossequencearealsopresentintheBornovaFlysch
şıIklar –Cenom.Campan. ğSpilda–Cenom.Maastric Evkaftepe–NorianCenom. Gelenbe–NorianEocene 5S. mctbİşiouoiinntdnTttsdieh(unlkFeecui,hge2AM.bs0n4leu0oi,ss0pcBoik;awrzsniİonaşwirik(cndomMtueciainlakddntr,donbb2loeet0ehnt0dTea2iarftl)fiAie.a.,clsbT1upshi9lilatcae7n)tt2ofMwo;sdhriEidimtarsdhdltliloonemoğwgfTaaurnjiKmoisahaersartbsfraraiirbocnleu–.me,aCr1kulrt9sihenm9tiena0ebmc;sseetMeagootdinuarniissemxsss.iee,nwnaatetinntarhdd--
3
ne val is represented by carbonates except some red sandstone
–5681E4257948N–6230E4258473N–2304E4258516N–2756E4258582N –0881E4272711N–1327E4273232N –8681E4324903N–7718E4324333N mandlieinthezo iaJbanurtaerteueaxsrscelsiaatice.cytei1laoer7nnsv0deii0nlssAm.5tlThb0hie0taehnLmitachctk(aei,cErkTbrandronioenadsğsassataienorcse.feTbttshhyeaeepla.Ja,Mupr1raiaa9dtrs9edasd0llilec;e–flİTrLşourioinmnawtsceesoktirnhc,C–fe2oLr0reiom0atvas2iesctir)eycl.oymcTuinahsargebrckaoAUernlbpdbaopitbaneenysr-
B:052F:052B:052F:052 B:053F:053 B:055F:055 8datu ccaornbgolonmateersasthe,oswiltsatnonuepawnadrdmduedesptoennein(gFicgh.4a)ra.Tctheirswanadsfaorleloowveedrlbaiynubpy-
97 lift, deformation and erosion in the Cenomanian–Santonian interval
1
n beforethe deposition oftheUpper Cretaceous series,asshown by
a
Naldöken –LiassicCenom. –BarremianTuron. Keçiliköy–NorianTuron. ğEmirolu–NorianTuron. TM)ontheEurope İtfclişohemireonmeutoessabtk.bosSleenyitremvoaainlbl.ta,liroo2rocn0csk0tktsr7hsa;aitrntOiagntkrhtgaaheiypnehCagainBcimdnorrpeSanailgoaynetvaiiakafornono,Fsbm1lyaa9ssEr9acea3hlr)ocl.yobZnsoTegnrrlieovasme(sdEiecrridnatotoemğEsaaalnrine,lyyu1Con9frc9eot0thnaae--;
U TheUpperCretaceoussequencefromtheKaraburunisbestknown
(
or fromtheBalıklıovalocalityinthecentreofthePeninsula(Fig.2).The
014N333N 602N821N 418N484N 463N550N Mercat Bataelsık,lwıohvaichUpapreeroCvreertlaacineobuys sreedqeupeonscietesdtacratsrbwonitahtebadseablrcisonfogllloomweerd-
–037E4261–820E4261 –836E4255–138E4254 –668E4310–559E4310 –280E4354–400E4354 Transverse bs1iy9lt9sr0teobdn).epPeseellaaqgguiicecnflocimerae(msBtironinnifkeemsra,awdnanhtieechtthaepl.a,as1gs9e7uo7pf;tEhinleçtoireedatapslhe.,laa2lge0i–1cs0la;imnEdresdsttoooğnnaeen–s,
B:0520F:0519 B:0531F:0530 B:0552F:0552 B:0570F:0570 niversal MasaeaasrtlryicChatmiapnainniaangeto(eBarrinlykmMaaansntreicthatli.a,n1;9t7h7e;oEvredrolyğianng,fl1y9s9c0hbi)s.aTlhsoe
U flyschsequencewithamin.thicknessof1000metersistectonically
n
ei overlain by Triassic carbonates. Compared to the matrix of the
ocene atesar Bfoorrmnosvaa cFolyhsecrhenZtonseeq,utehneceB;aliıtklpıorvoabaflbylyschcoirsrelsitptolenddseftoormanedeaarnldy
Kocaçay –Maastricht.Pale şKemalpaa–Cenom.Coniac. ıSrtköy–NorianCenom. Urbut–NorianTuron. North.Thecoordin sFP(tFleyaingsgTic.enhhs2eou,ZfrloEaetnhlriadseetoiodoağbnneaspdenbor,etvsht1eiwte9dieo9aienn0pnbpoth)tafh.reteeThKnhteatyellmpyericecaci,aktorlphlibooxelcorooaercflnlkiyttt-yhmsseieonaqBrttturoheierxednn,sKcoeeaavrnraiiaegnbsFulutolyharfsuerctnhhcKeplaZaeBrosnaotnbisrnenus.arounuvlndaa
N, blocksranginginsizefromafewcentimeterstoseveralkilometers
ns. 53684N53562N42036N42260N37981N37677N46684N46583N46906N45667N 34996N34203N n;E,East; luqiuepeionnfcaeMdbeeusftootzrhomeiceredliamflryeessactlhosonmebaslotorcifkxst.hToehfesteybrplpoeecnfkotsuinanirdteei.pnIrnettdhhoeemKKiaanrlaaenbctiuklyrrumengaisodene-
o 2222222222 33 o
easuredsecti –0462215E4–0462735E4–0469673E4–0462360E4–0458398E4–0459258E4–0460572E4–0460324E4–0454364E4–0456948E4 –0553492E4–0553498E4 dofthesecti sflt(heEyqersducyoheoğnupacenneng,aee1nts9rtd9a0bttialnho)gec.kTiKsnhateaorracetbohnureertaudfcrnatpcbseteeluaqtrgwueiesceneilncnimetthheisseistvoTdenreireafyossrsiomircfreesCdghauaomlllaliporsawtwonsimiattrnhaormatinhgaeeel
hem B:F:B:F:B:F:B:F:B:F: B:F: F,en carbonates of the Karaburun sequence in the Kalecik region. The
oft on; Karaburunsequencerepresentsanintermediatestageinthedevel-
Table1Geographiccoordinates Karaburun –AnisianNorian Norian –NorianLias –RhaetianAlbian –Campan.Maastricht. ıSarkaya–NorianTuron. B,beginningofthesecti o5İszop.muCmTtiohrhen–enetAataBsnoctoktfrwantrrheioatelvhasamtutiFhotéulenlyrasseMncoghwefenZi.ttdohhenereteBhsioesrMiSnnaaokscvsaoairnfyFtaaalnycZdstocithnnheZethooCefnynetcholaerdthPicownCetositdmeapslol,enixngattnhhdee
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288 A.I.Okayetal./Tectonophysics568–569(2012)282–295
Fig.5.Stratigraphyoftheplatform-margin-typeblocksfromtheBornovaFlyschZone.Datasources:7.Keçiliköy(İşinteketal.,2007),8.Sırtköy(İşinteketal.,2007),9.Evkaftepe
(İşinteketal.,2007),10.Emiroğlu(İşinteketal.,2007),11.Sarıkaya(İşinteketal.,2007),12.Urbut(OkayandAltıner,2007),13.Gelenbe(OkayandSiyako,1993).Thenumbersare
keyedtothemapinFig.2.ForsymbolsseeFig.4.ForgeographiccoordinatesofthemeasuredsectionsseeTable1.
inthenortheastwiththeCretaceousblueschistsoftheTavşanlıZone thedeformedsandstoneandshaleoftheBornovaFlyschZonelietec-
(Figs. 1 and 2). Most of these contacts are covered by the tonically over the Triassic metamorphic rocks of the Sakarya Zone
Miocenesedimentaryandvolcanicrocks.ThecontactstotheSakarya and over the Cretaceous blueschists of the Tavşanlı Zone (Akyüz
and Tavşanlı zones are only exposed northeast of Balıkesir, where andOkay,1996).
Fig.6.MicrophotographsfromthemeasuredsectionsoftheMesozoiclimestoneblocksfromtheBornovaFlyschZone.Forthelocationofthesectionsandtheirbiostratigraphysee
Figs.2,4and5.(1)TriasinahantkeniandAulotortusfriedlifromtheRhaetiansequenceoftheEğridereblockinBornova.Sampleno.6034,scalebar:910microns.(2)Aulotortusfriedli
andTriasinahantkenifromtheRhaetiansequenceoftheEğridereblockinBornova.Sampleno.6034,scalebar:900microns.(3).PaleodasycladusmediterraneusfromtheLiassicse-
quenceoftheEğridereblockinBornova.Sampleno.6060,scalebar:1041microns.(4)ThinshelledbivalviabearingredlimestonefromtheuppermostRhaetiantoLiassicofthe
KeçiliköysequenceinManisa.Sampleno.6271,scalebar:2040microns.(5)CrinoidallimestonefromtheRhaetianoftheKırkağaçsequenceinManisa.Sampleno.5569,scalebar:
1692microns.(6)TriasinahantkenifromplatformtypeRhaetiansequenceofEmiroğluÇayırısequenceinKırkağaç.Sampleno.5801,scalebar:1010micron.(7)Aulotortusgr.sinuo-
susfromtheRhaetianoftheEmiroğluÇayırısequenceinKırkağaç.Sampleno.5821,scalebar:954microns(8and10)Calpionellaalpinafromtheredpelagiclimestonesfromthe
EmiroğluÇayırısequenceinKırkağaç(Fig.8)andEvkaftepesequenceinAkhisar(Fig.10).Sampleno.5713and5289,scalebar:114micronsand200microns,respectively.(9and
17).Globuligerinagr.oxfordianafromtheredpelagiclimestonesfrompassivemargintypesequenceofEmiroğluÇayırısequenceinKırkağaç.Sampleno.5764and5785,scalebar:
100micronand84micronrespectively.(11)RedmondoideslugeonifromplatformtypeDoggersequenceofNaldökenblockinBornova.Sampleno.5160,scalebar:827micron.(12,
22)HedbergellatrochoideabearinglateAptianredpelagiclimestonesoftheEmiroğluÇayırısequenceinKırkağaç.Sampleno.5776,scalebar:191micronsand378micronsrespectively.
(13)MuricohedbergellarischifromthelateAptianredpelagiclimestonesoftheEmiroğluÇayırısequenceinKırkağaç.Sampleno.5778,scalebar:185microns.(14)Gorbachikellasp.from
theupperAptianredpelagiclimestonesoftheEmiroğluÇayırısequenceinKırkağaç.Sampleno.5785,scalebar:115microns.(15)Saccocomasp.fromtheTithoniantoBerriasianred
pelagiclimestonesoftheEmiroğluÇayırısequenceinKırkağaç.Sampleno.5761,scalebar:181microns.(16)Praeglobotruncanasp.fromtheCenomanianpelagiclimestonesoftheSar-
ıkayainSoma.Sampleno.5761,scalebar:141microns.(18)RudistfromtheTuroniantoprobablelowermostSantonianoftheNaldökenblockinBornova.Sampleno.5880,sca-
lebar:10milimeters.(19)Helvetoglobotruncanahelveticafromthelower-middleTuronianpelagiclimestonesoftheEmiroğluÇayırısequenceinKırkağaç.Sampleno.5806,scalebar:
132microns.(20)MarginotruncanapseudolinneianaandMarginotruncanasp.fromthelower-middleTuronianpelagiclimestonesoftheEmiroğluÇayırısequenceinKırkağaç.Sampleno.
5818,scalebar:445microns(21,24)Caucasellasp.fromtheupperAptianredpelagiclimestonesoftheEmiroğluÇayırısequenceinKırkağaç.Sampleno.5764,scalebar:160and141
micronsrespectively.(23)Praeglobotruncanadelrioensis,RotaliporagreenhornensisandRotaliporasp.fromtheupperCenomanianpelagiclimestonesoftheSarıkayasequenceinSoma.
Sampleno.5551,scalebar:478microns.(25)RotaliporacushmaniandRotaliporaapenninicafromtheupperCenomanianpelagiclimestonesoftheSarıkayasequenceinSoma.Sample
no.5551,scalebar:378microns.
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290 A.I.Okayetal./Tectonophysics568–569(2012)282–295
Fig.7.GeneralizedsyntheticstratigraphyoftheMenderesMassif(Dürr,1975;Gutnicetal.,1979;Özeretal.,2001),Karaburunandplatform-typeblocksintheBornovaFlyschZone,
platform-margin-typeblocks(İşinteketal.,2007;OkayandAltıner,2007),andradiolarianchertsintheophioliticmélange(TekinandGöncüoğlu,2007,2009).ForsymbolsseeFig.4.
NorthofGölmarmara,limestoneblocksoftheBornovaFlyschZone the platform carbonates are dated by rudists as Cenomanian and
liewithalow-angletectoniccontactoverthemarbleandmicaschist Santonian–Campanian(Özer,1998).Theseneriticcarbonatesareun-
of theMenderesMassif(Akdeniz etal.,1980).TheBornova Flysch conformably overlain by thinly bedded recrystallized red pelagic
Zone is in contact with the Cycladic Complex north of Kuşadası limestones of Late Campanian–Maastrichtian (Özer et al., 2001) or
(Fig. 2). There, flysch with limestone, radiolarite and serpentinite Paleocene(Çağlayanetal.,1980)ages,whichpassupintoaflyschse-
blockslieswithasubhorizontaltectoniccontactoverthemicaschists quence with serpentinite and carbonate olistoliths (Çağlayan et al.,
of theCycladic Complex (BaşarırandKonuk,1981).Thecontactis 1980;Dürr,1975).Özeretal.(2001)describeaMiddlePaleocenepe-
characterized by a several meters thick brittle cataclastic zone, lagicfaunafromthecarbonatelensesintheflyschandGutnicetal.
which places unmetamorphosed limestone or sandstone over the (1979)mentionthepresenceofEarlyEocenenummulites.Theslight-
garnet-micaschists of the Cycladic Complex. The brittle faults be- ly metamorphosed Lower Tertiary flysch of the Menderes Massif is
tween the Bornova Flysch Zone and the Menderes Massif and the tectonically overlain by the Lycian Nappes (Fig. 2). The metamor-
CycladicComplexpostdatetheEocenemetamorphismofthelatter phismintheMenderesMassifisBarroviantypeandofEoceneage;
unitsandareprobablyextensionalbeingrelatedtotheexhumation the peak P-T conditions of the Alpine metamorphism close to the
ofthemetamorphicrocks. basement-coverinterfaceinthesouthernMenderesMassifareesti-
mated as ca. 8kbar and 550°C (Okay, 2001; Whitney and Bozkurt,
6.Stratigraphiccomparisonwiththeneighboringunits 2002) corresponding to burial depths of ca. 28km. The few Ar–Ar
whitemicaagesdatetheBarrovianmetamorphismoftheMenderes
The Mesozoic stratigraphy of the Menderes Massif shows close Massif to the range of 44Ma to 34Ma (Hetzel and Reischmann,
similaritytothatobservedintheplatform-typeblocksintheBornova 1996).IncontrasttotheMenderesMassif,theCycladicComplexhas
Flysch Zone (Fig. 5). It has a thick platform carbonate sequence of undergoneablueschisttoeclogitefaciesmetamorphism.Theageof
TriassictoCretaceousage(Dürr,1975;Gutnicetal.,1979;Çağlayan metamorphismiswellconstrainedbyRb–Sr,Ar–Arwhitemicaand
et al., 1980; Bozkurt and Oberhansli, 2001). The upper parts of Lu–Hf garnet methods as Early Eocene (ca. 52Ma, e.g., Bröcker and
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A.I.Okayetal./Tectonophysics568–569(2012)282–295 291
Enders,2001;Tomascheketal.,2003;Putlitzetal.,2005;Lagosetal., carbonateplatform.TheisolatedophiolitebodiesintheAnatolide–
2007). Taurides exhibit petrological and structural similarities suggesting
TheLycianNappestothesoutheastoftheMenderesMassifconsist thattheywerepartofalargeophiolitecomplex,comparableinsizeto
ofacomplexthruststackmadeupofcontinentalmarginsediments theSemailophioliteinOman(Dileketal.,1999;OkayandWhitney,
andophiolite(deGraciansky,1968;Gutnicetal.,1979;Şeneletal., 2010; Önen, 2003). The ages of the sub-ophiolite metamorphism in
1981). The basal parts of the Lycian Nappes show a low-grade HP/ the Anatolide–Taurides are also very similar (ca. 93Ma, Parlak and
LT metamorphism characterized by the presence of carpholite Delaloye,1999;Çeliketal.,2006)indicatingaCenomanianinception
(Rimmeléet al., 2003). The Lyciannappes are generally considered oftheophioliteobduction.TheHP/LTmetamorphismisdatedatca.
torootnorthoftheMenderesMassifwiththeimplicationthatthey 80MaintheTavşanlıZone(Sherlocketal.,1999)andca.63Main
constitutedthetectoniccoverovertheMenderesMassifduringthe theAfyonZoneandintheLyciannappes(Pourteauetal.,2010a,b)il-
Eocene,andwereerodedduringtheOligocene–Mioceneexhumation lustrating the progressive burial of the Anatolide–Tauride Block
oftheMassif.Platform-margin-typesequencesaredescribedfromthe undertheobductedophiolite.Theagesofdepositionanddeforma-
upperpartsoftheLycianNappes,especiallyfromtheDomuzdağıunit, tionof theBornova FlyschZoneoverlapwith theHP/LTmetamor-
whichformsatectonicsliceintheophioliticmélange(Şenel,1997). phismintheTavşanlıandAfyonzones(Fig.8)implyingalinkwith
Shallow marine platform carbonates, Norian–Rhaetian in age, form thecontinentalsubductionandtheformationoftheBornovaFlysch
the base of the Domuzdağ sequence (Fig. 7). These are overlain by Zone.
Liassic limestones, about 10m thick, which are apparently lacking
in the equivalent blocks in the Bornova Flysch Zone. The overlying
condensed uppermost Jurassic–lowermost Cretaceous pelagic 7.2.TheBornovasegmentoftheİzmir–Ankarasuture
carbonates, marking the collapse of the carbonate platform, are
found in both units (Fig. 7). In the Domuzdağ and Urbut sections, Theİzmir–AnkarasutureformsthemainTethyandividebetween
theTithoniantoLowerCretaceouscarbonatesshareacommoncal- thePontidesandtheAnatolide–TauridesinTurkey.Inthewestern
pionellidassemblageofTintinnopsellacarpathica,Calpionellaalpina, Anatolia, it is strongly segmented with a sharp 55° bend close to
Calpionellopsis oblonga, Calpionellites darderi. In the Domuzdağ se- Balıkesirandasmoother90°bendnorthwestofİzmir(Fig.1).The
quence,thelowermostCretaceouspelagiccarbonatesectionextends Balıkesir bend is considerably larger than the rotation induced by
down to the upper Tithonian, which is only 10cm thick (Poisson, the post-Oligocene Aegean extension,which islessthan 30°(e.g.,
1977). In both the Domuzdağ and Urbut sections, the Cretaceous KisselandLaj,1988).TheBornovaFlyschZoneislocatedbetween
pelagiclimestoneslieunconformablyovertheLowerCretaceous,and the Balıkesir and İzmir bends and extends parallel to the SW-NE
inplacesdirectlyovertheUpperTriassiccarbonates.Similarcondensed trendingBornova segmentoftheİzmir–Ankarasuture.Similarly,the
Mesozoic sequences are also described from the central Taurides trend of the internal high-pressure metamorphic belts, the Tavşanlı
(Monod, 1977). The presence of platform–margin-type sequences in andAfyonzones,areeast–westandobliquetotheBornovasegment
theLycianNappessupportsthenorthernoriginoftheLycianNappes oftheİzmir–Ankarasuture(Fig.1).
andimpliesthatalargecomplexthrustsheetcoveredthewestern TheBornovasegmentoftheİzmir–Ankarasutureconstitutesalso
AnatoliaduringtheLateCretaceous. a paleotectonic lineamentseparatingthe Early Cretaceous ophiolite
obductioninGreecefromtheLateCretaceousoneinAnatolia(Okay
etal.,1996).Ophioliteandoceanicsedimentaryrockswereemplaced
7.Discussion duringtheearliestCretaceous(ca.145Ma)southwestwardoverthe
Pelagonian zone (e.g., Jacobshagen, 1986; Papanikolau, 2009;
7.1. Continental subduction, ophiolite obduction and the deposition of Robertsonetal.,1991).ThisearliestCretaceousophioliteobduction
theBornovaFlysch can be traced as far southeast as the Sporades islands (Fig. 1,
Jacobshagen and Wallbrecher, 1984), but there is no evidence for
DuringtheLateCretaceous,thenorthernmarginoftheAnatolide– ophioliteobductionontheKaraburunPeninsula,wherethisperiodis
Tauridecarbonate platform was subducted northward in an intra- marked by a disconformity of latest Jurassic-Early Cretaceous age
oceanic subduction zone and underwent HP/LT metamorphism (Erdoğan et al., 1990; İşintek, 2002). On the other hand, the Late
(e.g. Okay and Whitney, 2010). The subduction of the continental CretaceousophioliteobductionovertheAnatolide–Tauridecarbonate
crustcanalsobeviewedastheobductionofophiolite,accretionary platformdidnotextendintotheAegeanwestoftheBornovasegment.
complexandslicesofcontinentalmarginovertheAnatolide–Tauride Oneexplanationforthisalternatingandmutuallyexclusiveobduction
Fig.8.RelationbetweenmetamorphismoftheAnatolide–TaurideBlockandthedepositionoftheBornovaFlysch.Seethetextforsourcesofdata.