Reconstructing the geometry of central Anatolia during the late cretaceous: Large-scale cenozoic rotations and deformation between the Pontides and Taurides

Abstract

The CentralAnatolianCrystallineComplex(CACC)exposesmetamorphic,ophioliticandigneousrocks that wereformedanddeformedduringclosureoftheNeotethyanocean.TheCACCislocatedincentral Turkey,betweenthePontidesinthenorthandtheTauridesinthesouth,separatedbymajorfault zones.Compositeplutonsintrudedthemeta-sedimentaryandophioliticunitsbetween 95 and75Ma, and formlinearmagmaticbelts( 100 kmlong)alongthewesternandnorthernmarginsoftheCACC. ExhumationofthemetamorphicandigneouscomplexwasfinalizedbythePaleocenetime.Inthis study,wepaleomagneticallystudyfifteenplutonsspanningtheentirenon-deformedupperCretaceous granitoidbelttotestwhethertheinitialconfigurationoftheCACCwasmodifiedbyverticalaxis rotationsafteritsexhumation.Ourresultsshowthreeinternallycoherentdomainswithsignificantly differentvertical-axisrotations:(1)inthenorth-east,theAkda˘g–Yozgatblock(AYB)records 151 clockwiserotation,(2)inthenorth-west,theKırs-ehir–Kırıkkaleblock(KKB)shows 6–91 counter- clockwiserotationand(3)inthesouth-west,theA˘gac- ¨oren–Avanosblock(AAB)shows28–351 counterclockwiserotation.Weproposethattheserotationswereaccommodatedbytwotranspres- sionalfaultzones:inthesouth,theexistingSavcılıThrustZonebetweentheAYBandKKBandinthe north,thenewlyintroducedDelice–KozaklıFaultZonebetweentheKKBandAAB.Therestored configurationoftheCACCsuggeststhatthethreeblockswerelargelyalignedina NNEorientationat an earlystageoftheirhistory.Consequently,sincethelateCretaceoustheshapeoftheCACCwas affectedbylargescaledeformation,resultinginitsmoderntriangulargeometry.Thisdeformation phase isbestexplainedasaresultofcollisionoftheCACCwiththePontides.