Linking slab break-off, Hellenic trench retreat, and uplift of the Central and Eastern Anatolian ...

22 Pages·2013·12.53 MB·English

Earth-ScienceReviews128(2014)147–168
ContentslistsavailableatScienceDirect
Earth-Science Reviews
journal homepage: www.elsevier.com/locate/earscirev
Linking slab break-off, Hellenic trench retreat, and uplift of the
Central and Eastern Anatolian plateaus
T.F.Schildgena,⁎,C.Yıldırımb,D.Cosentinoc,d,M.R.Streckera
aInstitutfürErd-undUmweltwissenschaften,andDFGLeibnizCenterforSurfaceProcessesandClimateStudies,UniversitätPotsdam,14476Potsdam-Golm,Germany
bEurasiaInstituteofEarthSciences,IstanbulTechnicalUniversity,Istanbul,Turkey
cDipartimentodiScienzeGeologiche,UniversitàdegliStudiRomaTre,Rome,Italy
dIstitutodiGeologiaAmbientaleeGeoingeneria(IGAG-CNR),Rome,Italy
a r t i c l e i n f o a b s t r a c t
Articlehistory: TheCentralandEasternAnatolianplateausareintegralpartsoftheworld'sthirdlargestorogenicplateau.Inthe
Received23January2013 pastdecade,geophysicalsurveyshaveprovidedinsightsintothecrust,lithosphere,andmantlebeneathEastern
Accepted13November2013 Anatolia.Theseobservationsarenowaccompaniedbyrecentsurveys inCentralAnatoliaandnewdata
Availableonline21November2013
constrainingthetimingandmagnitudeofupliftalongitsnorthernandsouthernmargins.Togetherwithpredic-
tionsfromgeodynamicmodelsontheeffectsofvariousprocessesonsurfacedeformationanduplift,theobser-
Keywords:
vationscanbeintegratedtoidentifyprobablemechanismsofAnatolianPlateaugrowth.
Anatolianplateau
AchangeoverfromshorteningtoextensionalongthesouthernmarginofCentralAnatoliathatiscoevalwiththe
Surfaceuplift
NorthAnatolianFault startofupliftcanbemosteasilyassociatedwithoceanicslabbreak-offandtearing.Thisinterpretationissupport-
Slabbreak-off edbytomography,deepseismicity(orlackthereof),andgravitydata.Basedonthetimingofuplift,geophysical
EratosthenesSeamount andgeochemicalobservations,andmodelpredictions,slabbreak-offlikelyoccurredfirstbeneathEasternAnato-
Hellenictrench liainmiddletolateMiocenetime,andpropagatedwestwardtowardCyprusbythelatestMiocene.Alternatively,
thebreak-offnearCypruscouldhaveoccurredinlatePliocenetoearlyPleistocenetime,inassociationwithcol-
lisionoftheEratosthenesSeamount(continentalfragment)withthesubductionzone.Upliftatthenorthern
marginofCentralAnatoliaappearstoresultfromcrustalshorteningstartinginthelateMioceneorearlyPliocene,
whichhasbeenlinkedtothebroadrestrainingbendoftheNorthAnatolianFault.Theuplifthistoryoftheinterior
ofCentralAnatoliasincethelateMioceneisunclear,althoughshorteningthereappearstohaveendedbythelate
Miocene,followedbyNE–SWextension.Thischangeinthedeformationstylebroadlycoincideswithfaster
retreatoftheHellenictrenchaswellasupliftofthenorthernandsouthernmarginsofCentralAnatolia.
Thesedifferenteventsthroughouttheplateaumaybelinked,asfasterretreatoftheHellenictrenchhasbeenpre-
dictedtooccurafterslabbreak-off,whichcouldhaveinducedextensionofCentralAnatoliaandhelpedtoform
theNorthAnatolianFaultthroughacceleratedwestwardmovementofAnatoliarelativetoEurasia.Correlative
geochronologicevidencethatwesummarizeheresupportsthehypothesisthatthegeodynamicactivitythrough-
outtheAegean–AnatoliandomainstartinginlatestMiocenetoearlyPliocenetimedefinesaseriesofeventsthat
mayallbelinkedtoslabbreak-off.
©2013ElsevierB.V.Allrightsreserved.
Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 148
2. PaleotopographyalongthesouthernmarginoftheCentralAnatolianPlateau(CentralTaurides) . . . . . . . . . . . . . . . . . . . . . . . . 149
2.1. Paleotopographicconstraintsat7Ma . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 150
2.2. Paleotopographicconstraintsat5Ma . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 151
2.3. Paleotopographicconstraintsat1.6Ma . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 151
2.4. Creatingpaleotopographicmaps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 151
3. Upliftconstraintsfromotherregions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 153
3.1. UpliftofthenorthernmarginoftheCentralAnatolianPlateau(Central Pontides) . . . . . . . . . . . . . . . . . . . . . . . . . . . 153
3.2. UpliftoftheinterioroftheCentralAnatolianPlateau . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 153
3.3. UpliftoftheEasternAnatolianPlateau . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 154
⁎ Correspondingauthor.Tel.:[phone].
E-mailaddress:[email protected](T.F.Schildgen).
0012-8252/$–seefrontmatter©2013ElsevierB.V.Allrightsreserved.
http://dx.doi.org/10.1016/j.earscirev.2013.11.006
148 T.F.Schildgenetal./Earth-ScienceReviews128(2014)147–168
4. Crustalscaledeformation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 154
4.1. CrustalshorteningatthenorthernmarginoftheCentralAnatolianPlateau . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 155
4.2. StructuralevolutionofthesouthernmarginoftheCentralAnatolianPlateau . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 156
4.3. StructuralevolutionoftheinteriorofCentralAnatoliaandtheAegean . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 157
4.4. StructuralevolutionofEasternAnatolia . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 157
5. Geophysicalperspectivesonthecrust,lithosphere,andsubductingslabs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 157
6. Discussion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 158
6.1. Crustalshorteningandthickening . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 158
6.2. EratosthenesSeamount(continentalfragment)subduction/collision . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 160
6.3. Lithosphericslabbreak-offandtearing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 160
6.4. Lithosphericdelaminationanduppermantleconvection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 160
6.5. Linkingslabbreak-off,HellenictrenchretreatandupliftoftheCentralandEasternAnatolianplateaus . . . . . . . . . . . . . . . . . . 162
7. Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 162
Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 164
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 164
1.Introduction marginsofbothregions(Figs.1and2).WhileEasternAnatoliaexhibits
symmetricplateaumorphologyinaN–Stopographicswathprofile
Awiderangeofgeodynamicmechanismshasbeeninvokedtoex- (Fig.1C),CentralAnatoliahasalowerinteriorcomparedtoitsmargins,
plainthegrowthofhightopographyinorogenicbeltsandplateaus.In andshowsadistinctasymmetryinitsminimumelevations,reflecting
somecases,asinglemechanismcapableofinducingbroad,regionalup- thepredominantlynorthward-directeddrainage(Fig.1B).
lift,suchaslithosphericdelamination,hasemergedasafavoredinter- TheArabia–EurasiacollisionattheeasternendoftheAegean–
pretation,forexampleintheSierraNevada(Jonesetal.,2004;Zandt AnatoliandomainisinferredtohavestartedinlateEocene/Oligocene
etal.,2004)andthesouthernCentralAndes(KayandKay,1993;Kay time (e.g., Jolivet and Faccenna, 2000; Agard et al., 2005; Dargahi
etal.,1994;Yuanetal.,2002).Often,however,delaminationonlyoccurs et al., 2010; Ballato et al., 2011; McQuarrie and van Hinsbergen,
aftersignificantcrustalandlithosphericshorteningandthickening, 2013),ormorespecificallyintwostagesbetween36and20Maand
whichitselfshouldproduceisostaticuplift.Suchtemporalchangesin after20Ma(Ballatoetal.,2011),andwasfollowedbycrustalshorten-
upliftmechanismshavespurredinvestigationsintotherelativecontri- ingacrossEasternAnatolia(Şengöretal.,2008).DespitealateCreta-
butionsofcrustalshortening,lithosphericthinning,lowercrustalflow, ceous to Eocene history involving shortening and the accretion of
magmaticaddition,orotherprocessesinproducinguplift(e.g.,Dewey severalcontinentalfragments(e.g.,ŞengörandYılmaz,1981;Dixon
andBurke,1973;FroidevauxandIsacks,1984;Allmendingeretal., andRobertson,1984;Tekelietal.,1984;Şengöretal.,1985;Polat,
1997;Şengöretal.,2008).Furthercomplicationsariseinregionsnear 1992; Şengör and Natal'in, 1996; Okay and Tüysüz, 1999; Tüysüz,
oceanicsubductionzones,wherethesubductionofoceanicridges,sea- 1999;AndrewandRobertson,2001;SunalandTüysüz,2002;Parlak
mounts,oroceanicplateaus(Livaccarietal.,1981;Cloos,1991;Espurt and Robertson, 2004; Okay et al., 2006; Pourteau et al., 2010;
etal.,2008),changesinslabdip(Jordanetal.,1983;Gutscheretal., Robertson et al., 2012; Pourteau et al., 2013), Central Anatolia has
2000), magmatic underplating (Brown, 1993), and slab break-off predominantlymovedwestwardrelativetoEurasiasincethetimeof
(DaviesandvonBlanckenburg,1995)mayallpotentiallydeformand Arabiancollision,accommodatedalongtheNorthandEastAnatolian
elevatetheoverridingplate.Morerecently,theeffectsofuppermantle strike–slipfaults(Ketin,1948;McKenzie,1976;Şengör,1979;Dewey
flowinproducingdynamictopographyhavebeenconsideredcapableof andŞengör,1979;Şengöretal.,1985).ContinuedArabia–Eurasiacon-
producingkm-scaleuplift(Boschietal.,2010;FaccennaandBecker, vergencemaycontributetothiswestward“escape”ofAnatolia,butroll-
2010;Karlstrometal.,2012),whilethedevelopmentoflarge,mantle- backoftheHellenictrenchislikelythepredominantforce(LePichon,
scaleconvectioncellsmayberesponsible fortheinitialshortening 1982;Jolivetetal.,2013),particularlyconsideringGPSdatashowing
seeninmajororogenicplateausliketheAndesandTibet(Faccenna westward movement of Anatolia relative to Eurasia that increases
etal.,2013). towardthetrench(Reilingeretal.,1997).
Theworld'slargestorogenicplateausinTibetandtheAndesaretyp- ThetectoniclinksacrosstheAegean–Aantolianregionarefairly
icallyviewedasresultingfromacombinationofthesedeep-seatedpro- clear,butlessobvioushavebeenthemechanismsthathavecontributed
cesses,andappeartohavegrowninbothelevationandarealextent tothegrowthoftheAnatolianPlateauovertime,andifthosemecha-
throughtime(e.g.,Isacks,1988;Allmendingeretal.,1997;Tapponnier nismsmayberelatedtooneanother.WhilehightopographyinEastern
etal.,2001).Onceattainingcriticalelevations,theinfluenceoflocal Anatoliaislargelybelievedtoresultfromlithosphericslabdelamination
topographichighsonthedistributionandamountofrainfallandconse- andbreak-off(Keskin,2003;Şengöretal.,2003;Keskin,2007;Şengör
quenterosionanddepositionpatterns(e.g.,BookhagenandStrecker, etal.,2008),recentworkinCentralAnatoliapointstomultipleuplift
2008; Roe et al., 2008) can also help to create a regional plateau mechanismsthatvaryacrosstheregion.AlongthenorthernCentralAn-
morphology (Sobel et al., 2003). In some cases, these feedbacks atolianPlateaumargin,Yildirimetal.(2011)suggestedthatthemost
betweentectonicsandsurfaceprocessesappeartostronglyinfluence recentphaseofupliftresultsfromstrainaccumulationalongthebroad
theevolutionofplateaumargins(e.g.,Hodgesetal.,2004;Strecker bendoftheNorthAnatolianFault.Alongthesouthernplateaumargin,
etal.,2007,2009). upliftmechanismsthathavebeenproposedinclude:(1)slabbreak-off
Iforogenicplateausgrowgraduallythroughtime,therelatively (Cosentinoetal.,2012);(2)upwellingasthenospherethroughaslab
smallAnatolianPlateaumaybeanearly-stageanalogfortheworld's tear(Schildgenetal.,2012b);and(3)acombinationofslabbreak-off,
largerorogenicplateaus.High-elevation(2to2.5kmaverage),high- slabtearing,andcollisionofacontinentalfragmentwiththesubduction
relieftopographyinEasternAnatoliatransitionstolowerelevation zonesouthofCyprus(Schildgenetal.,2012a).Upliftintheinteriorof
(1.5to2kmaverage),low-relieftopographyinCentralAnatolia,with CentralAnatoliaisdifficulttoconstrain,buthasbeensuggestedtoresult
high-relief mountain ranges bounding the northern and southern fromlithosphericdelamination(Bartoletal.,2012),ormantleflow
T.F.Schildgenetal./Earth-ScienceReviews128(2014)147–168 149
A
B C
Fig.1.(A):Regionalmapshowingtopography(ShuttleRadarTopographyMissionlevel3data,Jarvisetal.,2008)andmajortectonicboundaries.CAP:CentralAnatolianPlateau;
EAP:EasternAnatolianPlateau;CP:CentralPontides;CT:CentralTaurides;BZS:Bitlis–Zagrossuture;NAF:NorthAnatolianFault;EAF:EastAnatolianFault;DSFZ:DeadSeaFault
Zone;ES:EratosthenesSeamount;PT:PaphosTransform;LV:LakeVan.Whitearrowswithnumbersinsiderepresentplatemovement(mm/yr)withrespecttoastableEurasia(Reilinger
etal.,2006).Dashedyellowrectanglesshow150-kmwideregionssampledfortopographicswathprofiles(minimum,mean,andmaximumelevations)acrossCentralAnatolia(B)and
EasternAnatolia(C).
patterns(Boschietal.,2010;FaccennaandBecker,2010).Thesevarious Anatolia:thenorthernmarginoftheCentralAnatolia,itsinterior,and
processesmaybelinkedtooneanother,asslabbreak-offhasbeensug- EasternAnatolia.Fromthissurfaceperspective,wemovetodeeper
gestedtohelpinducerollbackoftheHellenictrench,whichcouldin indicationsof uplift mechanisms, including structural deformation,
turnpullAnatoliawestwardandhelpcreatetheNorthAnatolianFault volcanicgeochemistry,andgeophysicaldata.Specifically,weexplore
(Faccennaetal.,2006)andalsoaffectmantleflowpatterns(LePichon howprocessesrelatedtolithosphericslabsubduction,mantleflow,
andKreemer,2010). andplateboundaryinteractionsmayhaveconstitutedaseriesoflinked
ThewealthofrecentdatafromCentralAnatoliathatinspiredthese eventsthattogethergeneratedtheCentralandEasternAnatolianpla-
interpretationsspansarangeofstructural,geophysical,geochemical, teaus, while also inducing extension from the Aegean to Central
geomorphological,andgeochronologicalobservations.Inthisreview, Anatolia.
weattempttosynthesizethedatathathavecontributedtovarious
proposedupliftmechanismsandexploretheirfeasibilityinthecontext 2. Paleotopography along the southern margin of the Central
ofpublishedgeodynamicmodelsandrefinementstothechronologyof AnatolianPlateau(CentralTaurides)
eventsthroughouttheregion.Weparticularlyfocusonhowrecentdata
fromCentralAnatoliahelplinkextensionalprocessesintheAegean Paleoelevationstudieshaveprimarilyfocusedonareaswheremulti-
withcollisionalprocessesintheeast,allwithinthecontextoforogenic kilometer-scaleuplifthasgivenrisetochangesinstablecarbonand
plateauformation. oxygenisotopecompositionsrecordedinpaleosols(e.g.,Chamberlain
Followingadetailedreconstructionofpaleotopographyinsouthern andPoage,2000;BlisniukandStern,2005;RowleyandCurrie,2006;
CentralAnatolia,wesummarizeupliftconstraintsfromotherpartsof Garzione et al., 2008), or where changes in relief are large and
150 T.F.Schildgenetal./Earth-ScienceReviews128(2014)147–168
Fig.2.Topographicreliefmapcreatedwitha15-km-widemovingwindow.Majortectonicboundaries(asinFig.1)areshownforreference.Thinblacklinesshow2000-m
elevationand−2000-mbathymetriccontours.
fast enough to impact cooling-age patterns in low-temperature biostratigraphyofmarinesediments;(2)radiometricdatingoftufade-
thermochronometers(e.g.,Houseetal.,1998;Clarketal.,2005a,b; positsandashes;(3)cosmogenicnuclideexposuredatingoffluvial
Schildgen et al., 2007; Flowers et al., 2008; Schildgen et al., 2009; strath terraces; and (4) subsurface seismic reflection and well log
Richardsonetal.,2010;Schildgenetal.,2010;Vallaetal.,2010).The data. Next, we summarize the data that we used to reconstruct
Central Anatolian Plateau, with its low relief, modest elevations paleotopographyat7Ma,5Ma,and1.6Ma,asparticularlygoodcon-
(typicallyb1km),andlimitedMioceneexhumation,isnearthelimit straintsexistforthosetimes.TheperiodencompassingtheMessinian
ofthesensitivityofstableisotopesandthermochronologytorecord SalinityCrisis(5.96to5.33Ma)isexcluded,aswidespreadchanges
upliftand/orreliefdevelopment.Fortunately,theregionoffersarange frommarinetobrackishorcontinentaldepositsanderosionofthe
ofalternativesforreconstructingtopography.Forexample,sedimentary basinmarginsduringthatintervalwererelatedtorapid,km-scalesea-
facieschangeswithtransitionsfrommarinetocontinentaldeposition levelfallintheMediterranean(e.g.,Clauzonetal.,1996;Krijgsman
offerclear anddatablehorizonsto pinpointtherise oftopography etal.,1999;Cosentinoetal.,2013)ratherthantosurfaceuplift.
abovesealevel,whilelandformssuchaspaleosurfaces,fluvialterraces,
lakepaleoshorelines,andmarineterracescanserveasreferencelevels 2.1.Paleotopographicconstraintsat7Ma
orstrainmarkersthatlocallyrecordsurfaceupliftanddeformation.
Forlargeriversclosetotheiroutlets,incisionratesderivedfromdated Muchofthemodernreliefalongthesouthernplateaumarginpost-
fluvialterracesanddeltasmaybeviableproxiesforsurfaceupliftrates datesthedepositionoflateMiocenemarinesediments,whichriseto
(e.g.,Demiretal.,2004;Westawayetal.,2004;Seyreketal.,2008; over2kmelevationintheCentralTaurides.Biostratigraphyonthese
Schildgenetal.,2012a;Yıldırımetal.,2013a,2013b).Thehighdensity sediments has yielded Langhian (15.97–13.65Ma, Ocakoğlu, 2002;
oftheselandformsandsedimentarydepositsinCentralAnatoliaoffer Bassant et al., 2005) to Serravallian (13.65–11.61Ma, Tanar and
an opportunity to reconstruct surface uplift with high spatial and Gökçen,1990;Cipollarietal.,2013a)agesintheMutBasin,although
temporalresolution,providinguniqueinsightsintothegeodynamic Cosentinoetal.(2012)reportedlateTortonianagesof8.35to8.10Ma
mechanismsofuplift. fromtheca.2-km-highmarlsnearthevillageofBaşyayla(Fig.3).The
ReconstructionsofpaleogeographyofthesouthernmarginofCen- additional~100mofmarinelimestonesabovethe8.35to8.10Ma
tralAnatolia(e.g.,Robertsonetal.,2003;Fleckeretal.,2005;Jaffey marlsimplythattheyoungestmarinesedimentsnearBaşyaylaare
andRobertson,2005)andfortheTethysregionasawhole(Şengör evenyoungerthan8Ma(Cosentinoetal.,2012).Similarly,theageof
andYılmaz,1981;RobertsonandDixon,1984;Dercourtetal.,1993; patchesoflateMiocenemarinesedimentsalongtheSWplateaumargin
ŞengörandNatal'in,1996;Popovetal.,2004,2006)haveusedophiolite nearthevillageofSarıalan(Deynouxetal.,2005;Fleckeretal.,2005)
outcrops,changesinsedimentfacies,andpaleomagneticrotationsto wasrefinedwithbio-andlithostratigraphyto6.7Mafortheuppermost
reconstructtheevolutionofdepositionalenvironmentsandshoreline sedimentsat1.5kmelevation(Schildgenetal.,2012b).Becausemarine
morphology.Weextendtheseeffortsbystudyingmultiplestepsinthe sedimentationcontinuedtoatleast6.7MaatSarıalan,andmorerecent-
evolutionoftopographyalongthesouthernmarginofCentralAnatolia. lythan8ManearBaşyayla,upliftintheareaabovesealevelstarted
Our reconstructions of paleotopography in this region utilize: (1) sometimeafterca.7Ma.
T.F.Schildgenetal./Earth-ScienceReviews128(2014)147–168 151
Fig.3.MapofthesouthernmarginoftheCentralAnatolianPlateauillustratinglocationsfromwhichdataarederivedtoreconstructpaleotopographicmaps.
OnlapoflateMiocenemarinesedimentsontoMesozoicbasement However,Cipollarietal.(2013b)arguedthatsimilaritieswiththeseis-
rocksrevealstheexistenceofpaleotopographichighsduringthelate micstratigraphyoftheAdanaBasincouldmeanthattheconglomerates
Miocene(Cosentinoetal.,2011,2012).Suchareaswerethesourcefor overlyingtheM-reflectorinsteadcorrelatewiththelateMessinian
Miocene conglomeratesdeliveredtothemarginsof theKöprüand conglomeratesoftheAdanaBasin.
Manavgatbasins(Fleckeretal.,1995,1998;Karabıyıkoğluetal.,2000; TheAdana,Manavgat,andAksubasinsremainedmarineintothe
Deynouxetal.,2005;Monodetal.,2006;Çineretal.,2008). earlyPliocene.IntheAdanaBasin,earlyZancleanmarinemarlsoutcrop
Areasfarthernorthwerepredominantlyterrestrialduringthelate nearthevillageofAvadan(Fig.3;Cipollarietal.,2013b).Inthesouthern
Miocene.OnlycontinentalsedimentationoccurredsincethelateOligo- halfoftheAksuBasin,marinesedimentsareasyoungasearlytomiddle
ceneintheAktoprakandUlukışlabasins(ClarkandRobertson,2002, Pliocene(Bizonetal.,1974;AkayandUysal,1985;Poissonetal.,2003;
2005;JaffeyandRobertson,2005),whichareboundedtothesouthby Sagular,2009;SagularandÇoban,2009;Poissonetal.,2011).Inthe
theCentralTaurides.IntheAltınapaBasin,lacustrinesedimentsre- ManavgatBasin,shallowmarinedepositioncontinuedupto~10km
vealedlateMiocenetoPliocenebiostratigraphicages(GögerandKıral, inlandfromthemoderncoastlinethroughearlyPliocenetime(Akay
1969; Görmüs, 1984; Eren, 1993; Özkan, 1998), while ashes dated andUysal,1985;GloverandRobertson,1998),andfinallyendedduring
with40Ar/39ArgeochronologyyieldedmiddleMioceneandolderdates thelateZanclean(GloverandRobertson,1998).
(Koçetal.,2012).Finally,Koçyiğitetal.(2000)describedearlyMiocene
toQuaternaryfluviallacustrinesedimentsintheAkşehirgraben,imply- 2.3.Paleotopographicconstraintsat1.6Ma
ingtheexistenceofaterrestrialplateauinterior,whileareastothe
southwerepredominantlymarine. NearthevillageofHacıahmetliintheMutBasin(Fig.3),marinesed-
imentsasyoungas1.6Maoutcropatupto1.2kmelevation(Yıldız
2.2.Paleotopographicconstraintsat5Ma et al.,2003; Schildgen et al.,2012a).Therapidgeneration of relief
after1.6Mathatisimpliedbythehighpresent-dayelevationofthesed-
WhilethemarinesedimentationwithintheTauridesimpliesthat imentsiscorroboratedbyrapid(0.52to0.66mm/yr)incisionratesof
theonsetofupliftoccurredsometimeafter7Ma,coarsefluvialcon- theGöksuRiverfromca.130katotoday,basedoncosmogenicexpo-
glomeratedepositioninseveralbasinsflankingtheCentralTaurides sure ages of fluvial strath terraces (Schildgen et al., 2012a). In the
startinginthelatestMioceneindicatesthatupliftlikelystartedprior Adana Basin, lower Pleistocene marine sediments were identified
toca.5.5Ma.NorthoftheCentralTaurides,fluvialconglomeratesof fromwell-logcuttingsafewtensofmetersabovesealevel(Cipollari
theAktoprakBasinoverlielateMiocenelacustrinesediments(Jaffey etal.,2013b).IntheAntalyaBasin,GloverandRobertson(2003)esti-
andRobertson,2005).SouthoftheTauridesintheAdanaBasin,the mated that freshwater tufa deposits started to be deposited in the
ageofthethickfluvialconglomeratesoftheHandereFormation(previ- regionby1.5to2Ma,implyingthatmostofthepresentcoastalarea
ouslyassociatedwiththePliocene,GürbüzandKelling,1993;Nazik, wasabovesealevelbyearlyPleistocenetime.
2004;DarbaşandNazik,2010)hasbeenrefinedthroughbiostratigra-
phy to be associated with the latest Messinian “Lago-Mare” event 2.4.Creatingpaleotopographicmaps
(5.60 to 5.33Ma, CIESM, 2008) (Cosentino et al., 2010a, 2010b;
Cipollarietal.,2013b;Farandaetal.,2013).Plioceneageshadalso Schildgenetal.(2012b)showedthatbyfittingasplinesurfaceto
beeninferredforcoarsedepositsoverlyingthe“M-reflector”intheoff- uplifted late Miocene neritic limestones, the cumulative post-late
shoreCilicia(Aksuetal.,2005)andAntalyabasins(İşleretal.,2005). Mioceneupliftisgreatestparalleltothemodernplateaumargin,and
152 T.F.Schildgenetal./Earth-ScienceReviews128(2014)147–168
Fig.4.PaleotopographicmapsofthesouthernmarginoftheCentralAnatolianPlateau.(A):7Mapaleotopography;(B):5Mapaleotopography;(C):1.6Mapaleotopography;D:present
topography.
T.F.Schildgenetal./Earth-ScienceReviews128(2014)147–168 153
decreasestowardthecoastandtowardtheplateauinterior.Thespline constituteasignificantorographicbarriertoprecipitationbythattime
surfacecanthenbesubtractedfromthemoderntopographytore- (Mazzinietal.,2013).AnalysesofOligocenetoearlyMiocenestableiso-
construct the late Miocene (ca. 7Ma) paleotopography (Schildgen topesacrosstheplateaurevealsimilarresults,withanapparentabsence
et al., 2012b). We constructed additional paleotopographic maps ofsignificantorographicbarriersatboththenorthernandsouthern
(Fig.4)bysubtractingfractionsofthesplinesurfacefromthemodern Central Anatolian Plateau margins by 20 to 16Ma (Lüdecke et al.,
topography.Weassumedthatthepatternofupliftrevealedbythelate 2013).Finally,aseriesoflow-relief,elevatedpaleo-erosionsurfaces
Miocenesedimentshasnotchangedthroughtime,sothatthroughout thatextendfromIstanbulthroughtheCentralPontideshavebeensug-
our reconstruction, the plateau margin is uplifted faster compared gestedtorepresentthevestigesofapaleosurfacethathasundergone
withcoastalandinteriorregions.Thisassumptionisdifficulttotest, differentialuplift(Yılmaz,2007).NearIstanbul,thelow-reliefsurface
buttheoccurrenceofthehighestearlyPleistocenemarinesediments remnantslieat40to300melevation(Yılmazetal.,2010),whilewithin
(Yıldızetal.,2003;Schildgenetal.,2012a)inasimilarlocationasthe theCentralPontides,theyoccuratca.1000to1500melevation(Fig.6).
highestlateMiocenemarinesediments(alongtheaxisoftheCentral Withoutknowingtheageorpotentiallydiachronousnatureofthesur-
Taurides) suggests that a broadly similar pattern of deformation face,itcannotbeusedtoquantifyupliftratesintheCentralPontides.
persisted.Wereconstructedthemapfor5Mabyassumingthatanup- Nonetheless,thepreservationoftheearlytomiddleMiocenemarine
liftrateof0.2mm/yrstartedintheMutBasinat7Ma,tobeconsistent sediments,togetherwiththelackofisotopicevidenceofarainshadow
withresultsreportedbyCosentinoetal.(2012)andSchildgenetal. by 8Ma and the paleosurface remnants, implies surface uplift and
(2012a,2012b).Becausethiswouldleadto0.4kmofupliftby5Ma, incisionofnomorethan1to1.5kmsincethelateMiocene.
or 20% of the 2-km elevation of the marine sediments today, we Geomorphicdataprovidesomecluestorecentdeformationpatterns
subtracted80%ofthesplinesurfacefromthemoderntopography.For andratesintheCentralPontides.IntheKastamonuBasin(Fig.6),in-
the1.6Matimeslice,weassumedthat1.2kmofupliftoccurredafter cisedfluvialstrathterracesandpedimentswereusedtodefineanaver-
1.6Ma(Yıldızetal.,2003;Schildgenetal.,2012a).The0.8kmofuplift ageincisionrateof0.27to0.29mm/yrsinceca.340ka(Yıldırımetal.,
thatoccurredbetweenca.7and1.6Marepresents40%ofthetotal2-km 2013b).Locallyfasterincisionratesoccurnearactivethrusts,indicating
ofuplift,therefore,wesubtracted60%ofthesplinesurfacefromthe thatupliftandincisionweredrivenbymotiononthrustfaults(Yıldırım
moderntopography. etal.,2013b).Moreover,latePleistocenemarineterracesalongthe
Aftercreatingtheinitialmaps,wecorrectedanyinconsistencies BlackSeacoastaroundtheSinopPeninsulaindicateupliftratesthat
betweenthepaleoshorelinepositionsandpublisheddescriptionsofma- decrease from 0.2mm/yr at the southern end of the peninsula to
rineversuscontinentalsedimentsthatweresummarizedintheprevi- 0.02mm/yratthenorthernend(Yıldırımetal.,2013a).Similarly,Qua-
oussections.Wealsoattemptedtoremovesomeartifactsofmodern ternarypaleo-deltasoftheKızılırmakRiver(~120kmdownstream
relief.Forexample,aftersubtractingfractionsofthesmoothsplinesur- fromtheoutletoftheKastamonuBasin,e.g.,Akkan,1970)werecorre-
facefromthemoderntopography,wereducedelevationsoverlong latedwithrelativesea-levelhighstandstoindicateacoastalupliftrate
wavelengths,buttheshort-wavelengthreliefofthemodernlandscape of0.2to0.3mm/yrduringthelast340ka(Demiretal.,2004).These
remained.Thisproblemwasmostprominentwheredeeplyincised upliftandriver-incisionrateestimatesareconsistentwithmodernver-
rivervalleysdraintothecoast.Inthoseareas,therivervalleyswere ticalvelocitiesoflessthan1mm/yr(0.4±0.7mm/yr)constrained
belowsealevelaftersubtractingthesplinesurface,resultinginirregular withPersistentScatterersInSARandGPSvelocitiesforthesameregion
shorelinesresemblingdrownedtopography.Becausetheshorelines (Peyretetal.,2013).Together,thedatasupportthehypothesisoflate
weremorelikelytoberelativelysmooth(assumingthatthemodernre- PleistoceneupliftthroughouttheCentralPontidesrelativetotheBlack
liefwasgeneratedafterthatregionwasuplifted),wemanuallychanged Sea.GiventhattotalupliftintheregionsincethelateMioceneisonly
theshorelinesinourfinalpaleotopographicmaps.Asimilarproblemoc- ca.1to1.5km,therecentincision/upliftratesrecordedintheCentral
cursinsomeinlandareas.Forexample,theErmenekBasinwasbelow Pontidescouldnothavebeenactiveformorethan4to5Myr.
sealevelafterthesplinesubtraction;however,themiddletolateMio-
cenemarinestratigraphysuggeststhatsedimentsalongwhatisnow 3.2.UpliftoftheinterioroftheCentralAnatolianPlateau
thesouthernsideofthevalleyrepresentdeepersedimentsdeposited
lateral to a platform, which is on the northern side of the valley Fewfirmconstraintsexistfortheuplifthistoryoftheinteriorofthe
(Jansonetal.,2010;Cipollarietal.,2013a).Theseobservationssupport CentralAnatolianPlateau.Poissonetal.(1997,2010)describedevi-
ascenariowherethemodernreliefofthevalleywasonlygeneratedfol- denceofanearlyMiocenemarinetransgressionintheSivasBasin,
lowingupliftandfluvialincisionthroughthemiddletolateMiocene whichisnowatca.1300melevation,atalocationthattransitionsbe-
sediments.Forthatreason,wechangedtheelevationsoftheErmenek tweenEasternandCentralAnatolia.Becausecurrentmeanelevations
Basintolieabovesealevelforthe5Mamap.Despitethesecorrections, intheCentralAnatolianPlateauinteriorarecloseto1km(Fig.1B),
smallerartifactspersist,whichcanbeseenintopographicprofilesex- andmuchoftheregionwasterrestrialsinceatleastearlyMiocene
tractedalongtransectsthatcrossthesouthernplateaumargin(Fig.5). time (Dercourt et al., 1993; Popov et al., 2004, 2006; Akgün et al.,
2007andreferenceswithin;alsoseeSection2.1),theinteriormust
3.Upliftconstraintsfromotherregions haveexperiencedb1kmofsurfaceupliftsincethelateMiocene.
Riverterracesalongthenorthward-flowingKızılırmakRiverinthe
3.1. Uplift of the northern margin of the Central Anatolian Plateau centralpartoftheplateaurevealameanincisionrateof0.08mm/yr
(CentralPontides) averagedoverthelast1.99Ma,or0.07mm/yraveragedoverthelast
404ka(Doğan,2011),whichis4×slowerthanincisionthroughthe
TopographicgrowthofthenorthernmarginoftheCentralAnatolian northernplateaumarginsinceca.340ka(Yıldırımetal.,2013b),and
Plateau,whichcomprisestheCentralPontides,ismoreambiguouscom- 8×slowerthanincisionthroughthesouthernplateaumarginsinceca.
paredwiththesouthernmargin.Theyoungestmarinesedimentsre- 130ka(Schildgenetal.,2012a).Theslowerincisionintheinteriorindi-
portedfromtheregionareat1040melevationintheDevrekâniBasin catesthateitherthenorthward-flowingKızılırmakRiveriscurrentlyin
(Fig. 6), with an estimated early to middle Miocene age (Tunoğlu, atransientstate,withupstreamportionsoftherivernotyetadjustedto
1991a,b),implyingca.1-kmofupliftsincethattime.Stableisotope fasterupliftthroughouttheregion,orthatfasteruplifthasoccurred
compositionsfromthe12to8MaTuğlulacustrinesectionoftheÇankırı alongtheplateaumarginscomparedtotheplateauinteriorsincethe
Basin(Mazzinietal.,2013),southoftheNorthAnatolianFault,further- latePleistocene(Yıldırımetal.,2013b).
more show less depletion compared with modern precipitation Overall,itremainsunclearhowmuchsurfaceupliftoccurredinthe
(Schemmeletal.,2013),implyingthattheCentralPontidesdidnot CentralAnatolianPlateauinteriorsincethelateMiocene,butitappears
154 T.F.Schildgenetal./Earth-ScienceReviews128(2014)147–168
2
Swath 1 Swath 2
Fig.5.SwathprofilesacrossfoursectionsofthesouthernmarginoftheCentralAnatolianPlateau.Eachprofilewasextractedfromthemoderntopographyandthethreepaleotopographic
maps,toillustratethetemporalevolutionoftopographyineachregion.Notethatthelong-wavelengthtopographychangesovertime,however,littlechangeoccurstoshort-wavelength
relief,duetothemethodsusedinreconstructingthepaleotopography.InSwath1,linesmarkingtheelevationprofilesat5Maand1.6Maaredashed,toindicateuncertaintyrelatedtothe
lackofinformationonchangesinupliftratesthroughtimefortheSWplateaumargin.
tohaveexperiencedlessupliftcomparedwithboththeCentralPontides generallycalc-alkalineincompositionandclusteredinthenorth
inthenorthandtheCentralTauridesinthesouth. (Pearceetal.,1990;Keskinetal.,1998,Keskin,2007).By6to7Ma,
predominantly alkaline volcanism had spread southwards
andeastwards(Pearceetal.,1990;Keskinetal.,1998;Sumitaand
3.3.UpliftoftheEasternAnatolianPlateau Schmincke,2013).Thisvolcanismandthechangesinvolcanicgeo-
chemistryhavebeenusedtoinferthatfundamentalchangesinthe
The2-to3-kmaverageelevationsoftheEasternAnatolianPlateau mantlelithosphereand/oruppermantlewerecoevalwiththestart
risesignificantlyhigherthanthoseoftheCentralAnatolianPlateau.In of uplift in Eastern Anatolia (Keskin, 2003; Şengör et al., 2003;
EasternAnatolia,theendofmarinesedimentationnearLakeVanduring Keskin,2007;Şengöretal.,2008).
theSerravallian(ca.12Ma)(Fig.1,Gelati,1975;Popovetal.,2004)and
atca.11MaintheKahramanmaraşBasin(southoftheBitlis-Zagrossu-
turezone)(Hüsingetal.,2009),coupledwithlarge-scaleunderthrust- 4.Crustalscaledeformation
ingofthe11Masediments(Hüsingetal.,2009)atteststothefinal
closureoftheNeotethysOceanandlimitsthestartofmoreregionalsur- Apartfromsurface-upliftstudies,structuralandgeophysicalstudies
faceuplift(e.g.,ŞengörandKidd,1979;Şengöretal.,1985,2008;Hüsing provideinsightsintotheprocessesthatcontributetotopographicevo-
etal.,2009).Arecentapatitefission-trackstudyindicatesaccelerated lution,includingcluesaboutcrustalstresspatterns,plate-boundaryin-
exhumationintheBitlis–Zagrosthrustzoneatthesuturebetweenthe teractions,thegeometryoflithosphericslabs,andthelikelihoodof
ArabianandEurasianplatesatca.12Ma(Okayetal.,2010),which delaminationofthemantlelithosphere.Inthefollowingsections,we
mayalsoindicatethestartofanupliftphase. summarizethestructuralevolutionofdifferentsectorsoftheCentral
Consistentwiththeestimatedonsetofupliftisthetimingandnature and Eastern Anatolian plateaus before moving on to geophysical
ofvolcanismintheregion(Fig.7).Earliesteruptionsatca.11Mawere constrainsinSection5.
T.F.Schildgenetal./Earth-ScienceReviews128(2014)147–168 155
A
B
C
Fig.6.Reliefmap(A)andtopographicmap(B)oftheCentralPontidesalongthenorthernmarginoftheCentralAnatolianPlateau.Blackdashedlinesoutlinehigh-elevationregionsoflow
reliefinbothmaps.Theselow-relief,elevatedsurfacesareinterpretedtoberemnantsofadifferentially-upliftederosionalpaleosurfacethatspansthenorthernmarginofTurkey.White
lineoutlinestheperchedDevrekaniBasin.SP:SinopPeninsula;KB:KastamonuBasin;TB:TosyaBasin;DB:DevrekaniBasin;NAF:NorthAnatolianFault.(C):Conceptualmodelforthe
CentralPontidesasabivergentorogenicwedgerelatedtoapositiveflowerstructuredevelopedoverashallowdetachmentsurfacelinkedtotheNorthAnatolianFault(modifiedafter
Yildirimetal.,2011).
4.1.CrustalshorteningatthenorthernmarginoftheCentralAnatolian shortenedandthickenedalonganorth-vergentdetachmentassociated
Plateau withaforelandfold-and-thrust-beltfromthePaleocenetotheEocene
(e.g., Şengör et al., 1985; Şengör, 1995; Okay and Tüysüz, 1999;
Following closure of the northern branch of the Neotethys and Tüysüz,1999;SunalandTüysüz,2002;Okayetal.,2006).Northofthe
collisionofthePontideislandarcwiththeSakaryacontinenttothe Pontides, the south-central and southeastern Black Sea margin is
southmainlyduringlateCretaceoustime,theCentralPontideswere currentlyundergoingshortening(BarkaandReilinger,1997;Cloetingh
156 T.F.Schildgenetal./Earth-ScienceReviews128(2014)147–168
Fig.7.SimplifiedgeologicalmapofTurkeyderivedfrom1:500,000scalemappingfromtheMadenTetkikveAramaGenelMüdürlüğü(MTA),Ankara,Turkey.Allbrownregionsindicate
pre-Miocenerocks.Majortectonicboundaries(asinFig.1)areshownforreference.
etal.,2003).AtthesouthernborderoftheCentralPontides,which 4.2.StructuralevolutionofthesouthernmarginoftheCentralAnatolian
marksthenorthernboundaryoftheAnatolianmicroplate,theNorth Plateau
AnatolianFault(NAF)formsawidenorthward-convexbend(Fig.6)
thatisundergoingdextraldisplacementof24mm/yr(Reilingeretal., TheCentralTauridesalongthesouthernplateaumarginconsist
2006).Variationsinthelateralandfault-normalcomponentofmotion ofmultipleoceanicandcontinentalunitsshortenedinlateCretaceous–
occuralongthebroadrestrainingbend,withfault-normalshortening EocenetimeduringtheclosureoftheNeotethysandsubsequentcolli-
(upto8mm/yr)occurringbetweenEreğliandtheSinopPeninsula sionoftheTauruscarbonateplatformswiththecrystallinecomplexof
(31.5to35°Elatitude)(Yildirimetal.,2011).TheCentralPontidesof Central Anatolia (Şengör and Yılmaz, 1981; Dixon and Robertson,
thatregionarecharacterizedbythrustfaultsthatdeformQuaternary 1984;Pourteauetal.,2010,2013).TheBozkırandAladağnappeswere
sediments(Andrieuxetal.,1995;Yildirimetal.,2011)aswellasactive emplacedfromthenorthinlateCretaceoustomiddle–lateEocenetime
seismicity,suchastheMs6.5Bartınearthquakeof1968,whichshowed (Özgül,1976,1997;Monod,1977;AkayandUysal,1988;Bozkayaand
a thrusting focal mechanism (Ketin and Abdüsselamoğlu, 1969; Yalçin,2000;AndrewandRobertson,2001).Topographicgrowthfrom
McKenzie,1972).SouthoftheNAF,thereactivationofstructuresafter middleEocenetolateOligocenetimeledtowidespreadfluvialandlacus-
lateMiocenetimeintheÇankırıBasinappearstorelatetolocalblockro- trinesedimentation(ClarkandRobertson,2002,2005;Erişetal.,2005;
tationsalongfaultswithstrike–slipcomponents(Luciforaetal.,2013). Şafaketal.,2005),withlocalizedextensionandbasinformationsug-
Seismicreflectionstudieshaverevealeddeepthrustfaultsalongthe gestedtoresultfromsouthwardretreatoftheAfricanslab(Kempler
southern margin of the Black Sea and within the Central Pontides. andBen-Avraham,1987;Robertson,1998,2000;JolivetandFaccenna,
AcrossthesouthernmarginoftheBlackSea,thrustfaultsdeformQua- 2000).Subsidencethatresultedinachangefromterrestrialtomarine
ternarysediments,typicallywithprogressivesouthwardmigrationof sedimentationinsouthernTurkeyandformationoftheCiliciaBasin
deformation(Finettietal.,1988).Similarsouthward-migratingdefor- hasalsobeenexplainedbyslabretreat(Robertson,1998).Afinalstage
mationpatternswereobservedwithintheCentralPontides(Aydın ofshorteningdeformedOligocenelakesediments,butsincelateMiocene
etal.,1995;Şengör,1995;Damcıetal.,2004).Yildirimetal.(2011)in- time,small-scalenormalandstrike–slipfaultinghavepredominated
tegratedtheseismicreflectionlinesfromtheBlackSeaandfromwithin withintheCentralTaurides (Gloverand Robertson,1998; Ilgarand
theCentralPontideswithsurfaceevidenceofactivethrustingtosuggest Nemec,2005;Schildgenetal.,2012b).Moresubstantialdeformation,
thattheCentralPontidesconstituteanorogen-scale,bivergent,wedge- andmostofthepost-lateMiocenesurfaceuplift,appearstohaveaccu-
shapedtranspressivestructure,withashallowdetachmenthorizonthat mulatedthroughlong-wavelengthupwarpingoftheregion(Cosentino
mergeswiththeNAFatdepth(Fig.6C).Insupportofthisinferredim- etal.,2012).
portanceanddeepextentoftheNAF,recentwaveforminversionsof OffshoreseismicreflectionlinesinthecentralportionsoftheAntal-
teleseismicandregionaldatarevealalowvelocityzonealongtheeast- yaandCiliciabasinsrevealminorthruststhatmayberelatedtosalt
ernandcentralsectionsoftheNAFthatextendthroughthecrustand tectonics(Evansetal.,1978;Bridgeetal.,2005).Alongthenorthern
intotheuppermantle,likelyreflectingastructurallyweakzonethat marginoftheCiliciaBasinbetweenCyprusandsouthernTurkey(line
correspondstoTethyansutures(Fichtneretal.,2013). AofAksuetal.,2005),low-angle,south-directedthrustsaffectUnit2,