the north anatolian fault and complexities of continental escape abstract before the plio pleistocene the proto north anatolian fault zone was occupied by two separate faults a wnw striking right lateral eastern segment which extended to the black sea and a wsw striking left lateral western segment during the plio pleistocene most of the right lateral displacement on the eastern fault was transferred from the black sea extension to the western fault converting the latter to a right lateral structure and giving rise to the modern north anatolian fault zone this model explains the evidence first reported by hancock barka for an apparent plio pleistocene reversal of displacement along the western part of the fault the model may also account for the plio pleistocene change in regional stress in southwestern anatolia

paleomagnetic evidence for neogene rotational deformations in the aegean domain new paleomagnetic data are reported from the islands of skyros and lesbos in central aegea and the izmir foca region in western anatolia together with previous results obtained in northwestern greece and with results from northern aegea reported by others authors these data suggest that the lower miocene arc was almost rectilinear trending e w and that the curvature was acquired by opposed rotational deformations at each termination moreover the observed inclinations which are shallower than those expected on the basis of a geocentered dipole field suggest a large northward drift since middle miocene

timing kinematics and cause of aegean extension a scenario based on a comparison with simple analogue experiments abstract since the early 1970s most geodynamic models proposed for the eastern mediterranean consider that the initiation of extension in the aegean during the late middle miocene or later was a direct consequence of the westward extrusion of anatolia away from the arabia eurasia collision front in the late 1990s a few models have taken into account the increasing evidence for an earlier initiation of aegean extension arising mostly from the analysis of deformation within the various alpine metamorphic complexes of the area based largely on our own investigations we first present a review of the data that reliably constrain the minimum age for the initiation of extension in these complexes it shows that regional scale extension with a pattern of stretching orientations similar to that of the pliocene pleistocene was already strongly active in the aegean before the onset of arabian indentation into eurasia lower miocene vs middle or upper miocene this implies that the initiation of aegean extension did not result from the lateral extrusion of anatolia instead extension may have started owing to a process of gravity spreading of the continental lithosphere that had previously been thickened during alpine collision the main arguments favouring this interpretation are presented and a preliminary scenario is proposed for the neogene evolution of the eastern mediterranean in which lateral extrusion of anatolia occurred lately during southward spreading of the aegean lithosphere in order to test this hypothesis further physical experiments simulating the horizontal spreading of a continental lithosphere toward a free boundary have been carried out the analysis of various elements of the deformation field displacements strain rotations fault pattern and kinematics both in the experiments and in the aegean domain reveals an excellent agreement between the two not only do early stages of aegean extension appear to fit the gravity spreading hypothesis but so does the recent to present internal deformation of the aegean transverse e w active shortening observed in the northern aegean is commonly taken as one of the most striking pieces of evidence that aegean extension results from the lateral extrusion of anatolia the experiments indicate that such transverse shortening may equally develop as a result of pure gravity spreading associated with a pattern of faults and rotations that compares well with that of the northern aegean pure dextral shearing along some strands of the north aegean trough fault system and the related development of an asymmetric pattern of faults in the northern aegean are eventually the only features that evidently arise from the extrusion of anatolia since less than 3 ma finally we argue that during the early stages of aegean extension since at least 21 ma and until ca 11 ma the distribution of extensional strain on a regional scale has been controlled by the distribution of earlier thickening post thickening thermal weakening through partial melting of deep levels of the crust probably accounts for the localization of extensional strain within the areas of thick crust restoring the aegean in its most likely configuration at the onset of bulk crustal extension suggests that 1 the extensional strain rate remained roughly constant or has eventually decreased since the onset of aegean extension and 2 the amounts of extension before and after 16 ma have been roughly equal

rates of crustal deformation in western turkey as deduced from major earthquakes abstract western turkey has undergone dominantly n s extension probably since the late miocene this extensional regime caused the formation of e w trending grabens and similarly orientated normal faults the rates of deformation of the seismogenic layer caused by the major earthquakes ms 5 5 during the period between 1943 and 1983 are calculated for western anatolia this region is first analysed as a single system and then divided into two provinces namely the marmara and southwestern anatolian provinces which are investigated as two separate seismotectonic units the dominant mode of deformation in the marmara province is amounting to right lateral displacement 24 0 mm yr other modes of upper crustal deformation in this province can be explained by an average 7 1 mm yr n s extension 10 0 mm yr e w contraction and 0 13 mm yr thinning of a 10 km seismogenic layer the dominant mode of deformation in southwestern anatolia is about 13 5 mm yr extension in the n s direction this region is also undergoing e w extension of about 3 6 mm yr justifying the separation of marmara and southwestern anatolian provinces as two different seismotectonic provinces the average rate of thinning of the seismogenic layer in this area is 0 5 mm yr which is consistent with large scale normal faulting observed here it is found that n s extension in western anatolia increases from north to south while e w compression in the marmara province changes to e w extension in southwestern anatolia it is suggested that these kinematics may explain the present bending of the north anatolian transform forming a transtensional basin between the marmara and southwestern anatolian provinces

analyses of fault mechanisms and expansion of southwestern anatolia since the late miocene abstract neotectonic field studies and detailed analyses of neogene and quaternary fault mechanisms in southwestern anatolia enable us to recognize a succession of compressional and extensional events and to characterize the direction of corresponding regional stresses the three most important compressive phases occurred during the miocene and a much smaller one near the plio quaternary boundary the last one or two interrupted a widespread extension of much greater duration and amplitude the whole tectonic evolution resembles that of the aegean the large extension by normal faulting is consistent with a minimum stress along a nne ssw average direction it appears that this direction was n s during the pliocene and changed to ne sw sometime during the quaternary this dominant nne ssw extension which began during late miocene or earliest pliocene was related to the development of the southwestern anatolian graben system

progressive development of the buyuk menderes graben based on new data western turkey oblique and normal fault systems exposed in the buyuk menderes graben bmg region record two successive and independent complex tectonic events the first group tectonic event is defined by an e w extension related to n s contraction and transpression this group is responsible for the development of nw and ne trending conjugate pairs of oblique faults which controlled early middle miocene basin formation between the early middle miocene and plio quaternary strata exists an unconformity indicating a period of folding uplift and severe erosion associated with n s shortening the second group of events was the change in tectonic regime from e w extension to n s extension which controlled the formation of the buyuk menderes graben by three progressive pulses of deformation the first pulse of extensional deformation was initially recorded in the region by the exhumation of the deep part of the menderes massif mm with the development of the e trending buyuk menderes detachment fault bmdf the minimum age of this pulse is constrained by the older plio quaternary fluviatile deposits of the buyuk menderes graben that range in age from the plio pleistocene boundary interval to late pleistocene the second pulse which is marked by the rapid deposition of alluvial deposits initiated the formation of approximately e w trending high angle normal faults synthetic and antithetic to the buyuk menderes detachment fault on the northern margin during holocene times these faults are interpreted as secondary steeper listric faults that merge with the main buyuk menderes detachment fault at depth the third pulse was the migration of the buyuk menderes graben depocentre to the present day position by diachronous activity of secondary steeper listric faults these steeper faults are the most seismically active tectonic elements in western turkey according to the stratigraphic and structural data the n s extension in the buyuk menderes graben region produced a progressive deformation phase with different pulses during its plio quaternary evolution with migration of deformation from the master fault to the hangingwall the formation of diachronous secondary synthetic and antithetic steeper faults on the upper plate of the buyuk menderes detachment fault hence the southward migration of the deformation and of the buyuk menderes graben depocentre should be related to the evolution of detachment in the region the presence of the seismically active splays of secondary faults implies an active detachment system in the region this young plio quaternary n s extension in the buyuk menderes graben may be attributed to the combined effects of the two continuing processes in aegean region the first process is back arc spreading or probably the roll back of african slab below the south aegean arc which seems to be responsible for the change in the stress tensor from e w extension to n s extension the second and later event is the southwestward escape of the anatolian block along its boundary fault that is the north anatolian fault naf

plio quaternary stress state in the burdur basin sw turkey abstract this study defines the plio quaternary to present day stress regime in the burdur basin located at the northeastern end of the fethiye burdur fault zone in sw turkey this fault length which is considered the landward continuation of the pliny strabo trench is an important feature in sw turkey the inversion slip vectors measured on fault planes indicate a consistent normal faulting stress regime during plio quaternary time continuing into recent times as indicated by earthquake focal mechanism inversions both states have consistent nw se trending horizontal minimum stress axes 3 the orientation of fault sets is predominantly around the ne sw direction in the major fethiye burdur fault zone making the extension nw se the mean stress ratio is 0 74 indicating a triaxial stress state which is clearly different from radial extension the nw se extension is probably responsible for the formation of the burdur basin during plio quaternary time this extension which is probably caused by slab pull force due to the subduction process along the cyprus arc produces a dominant normal motion along the fbfz

late cenozoic stress distribution along the misis range in the anatolian arabian and african plate intersection region se turkey 1 this study defines the mio pliocene to present day stress regime acting at the northeastern mediterranean along the se border of the neogene adana basin along the misis range the inversion of earthquake focal mechanisms shows that the present day state of stress is dominantly a transtension combined the strike slip and extension with a consistent ene n83 e trending hmin 3 axis the inversion slip vectors measured on fault planes and chronologies between striations indicate a consistent strike slip stress regime that varied from transpressional initially to transtensional during pleistocene time with the latter continuing into recent times as indicated by earthquake focal mechanism inversions both states have consistent nnw n15 w trending compatible with nnw arabian drift direction and ene n75 e trending hmax 1 and hmin 3 axes respectively but have significantly different mean arithmetic stress ratio rm values rm 0 75 indicating transpression for the old regional stress regime and rm of 0 20 denoting transtensional for the younger regional stress regime the crosscutting of striations confirms also the change within the strike slip stress regime both stress regimes induce sinistral displacement along the major strike slip fault systems i e east anatolian fault karatas osmaniye fault the temporal stress regime change probably occurred during quaternary time and resulted from coeval influence of the superimposed forces owing to subduction processes in the southwest along the cyprus arc continental collision in the east and westward escape of the anatolian block in the north and west

early miocene to quaternary evolution of volcanism and the basin formation in western anatolia a review abstract western anatolia largely affected by extensional tectonics witnessed widespread volcanic activity since the early miocene the volcanic vents of the region are represented by epicontinental calderas stratovolcanoes and monogenetic vents which are associated with small scale intrusions as sills and dykes the volcanic activity began with an explosive character producing a large ignimbritic plateau all over the region indicating the initiation of the crustal extension event these rhyolitic magmas are nearly contemporaneous with granitic intrusions in western anatolia the ignimbrites emplaced approximately contemporaneous with alluvial fan and braided river deposits flowed over the basement rocks prior to extensional basin formation the lacustrine deposits overlie the ignimbrites the potassic and ultrapotassic lavas with lamprophyric affinities were emplaced during the late miocene pliocene the volcanic activities have continued with alkali basalts during the quaternary

slab detachment beneath eastern anatolia a possible cause for the formation of the north anatolian fault in this paper we discuss the possibility that the north anatolian fault naf results from the deep deformation of the slab beneath the bitlis hellenic subduction zone we described the tectonic evolution of the anatolia aegean area in three main steps before during and after the formation of the naf we remark that the tectonic conditions that are assumed to have triggered the formation of the naf i e collision to the east and extension to the west was already achieved before the onset of that strike slip fault system we also highlight that the formation of the naf was accompanied by the uplift of the turkish iranian plateau and by a surge of volcanism in the eastern anatolia collisional area and probably by the acceleration of the aegean trench retreat we show tomographic images from global p wave model of piromallo and morelli c piromallo a morelli p wave tomography of the mantle under the alpine mediterranean area j geophys res 108 2003 doi 10 1029 2002jb001757 showing that the slab beneath the bitlis collisional belt is not continuous and that its possible rupture pursues to the west at least up to cyprus and possibly up to the eastern end of the hellenic trench all these observations suggest that the plate tectonic re organization occurred in the late miocene early pliocene in the region results from slab break off in the bitlis area and from its lateral propagation to the west this idea is tested in analogue laboratory experiments which confirm that the break of the slab under the collisional belt may trigger 1 the acceleration of slab retreat to the west due to the increase in slab pull force 2 the indentation of the continent in the collisional area and 3 produce the conditions that permit the lateral escape of material towards the west and the formation of the naf

origin of late glacial holocene hemipelagic sediments in the aegean sea clay mineralogy and carbonate cementation abstract four hemipelagic lithological units are identified in the late glacial to holocene sediments in the aegean sea these lithologies are silty clay and clay in texture and include a varying mixture of loose terrigenous sediments supplied from the adjacent landmass gravel to sand sized cemented carbonate clasts and nodules sand to silt sized air born volcanic debris and biogenic remains sediment dispersal during the past 14 000 years was controlled mainly by the fluvial discharge rate by sea level variations which determined the proximity of basins to river mouths and by oceanographic conditions in the aegean sea cemented carbonate clasts and nodules occur in all sediments except unit c sapropel s1 they are well to friably cemented mottled to peloidal micrite or microcrystalline inter granular cement between terrigenous and bioclastic debris and the carbonate is 10 11 mole magnesium calcite during the deposition of sapropel s1 unit c the aegean sea was strongly stratified with colder more saline water masses occupying the deep basins which prevented the development of cemented carbonate nodules and clasts aragonite as pteropods and microcrystalline aragonite is present throughout the cores and together with the cemented carbonate clasts and nodules show that shallow pore waters in the aegean sea have been saturated to supersaturated with respect to both aragonite and magnesium calcite for at least the past 14 000 years results of xrd studies show that unit c sapropel s1 is characterized by lower smectite and kaolinite and higher illite and chlorite than the other units lower smectite illite and kaolinite chlorite ratios in unit c may reflect increased supply of illite and chlorite from european lowland rivers flowing into the black sea from rivers discharging directly into the northern and eastern aegean sea and decreased supply of kaolinite which is mainly of north african origin

footwall degradation styles and associated sedimentary facies distribution in se crete insights into tilt block extensional basins on continental margins abstract depositional facies resulting from footwall degradation in extensional basins of se crete are studied based on detailed geological maps regional transects lithological columns and outcrop photos during an extensional episode affecting crete in the late miocene early pliocene depocentres trending n20 e and n70 e were filled with fan deltas submarine mass wasting deposits sandy turbidites and fine grained hemipelagites sourced from both nearby and distal sediment sources deposition of proximal continental and shallow marine units and relatively deep marine turbidites and mass transport deposits occurred within a complex mosaic of tectonically controlled depocentres the new geological maps and transects in this work reveal that depositional facies in se crete were controlled by a their relative proximity to active faults and uplifting footwall blocks b the relative position depth and relative height above sea level of hanging wall basins and c the nature of the basement units eroded from adjacent footwall blocks distal sediment sources supplied background siliciclastic sediment hemipelagites which differ markedly from strata sourced from local footwalls in parallel mass transport of sediment was ubiquitous on tectonically active slopes and so was the presence of coarse grained sediment with sizes varying from large blocks 50 m wide to heterolithic mass transport deposits and silty sandy turbidites we expect similar tectono sedimentary settings to have predominated in tectonically active miocene basins of the eastern mediterranean in which hydrocarbon exploration is occurring at present and on rifted continental margins across the world

late cenozoic stress evolution along the karasu valley se turkey abstract this study defines the mio pliocene to present day stress regime acting at the northeastern corner of the eastern mediterranean region along the karasu valley i e the amanos range taking in the antakya osmaniye and kahramanmaras provinces the inversion slip vectors measured on fault planes and chronologies between striations indicate that the stress regime varied from transpressional initially to transtensional having consistent nw and ne trending hmax 1 and hmin 3 axes respectively there are significantly different mean stress ratio rm values however the older mean stress state is characterized by n151 11 e trending 1 and n59 12 e trending 3 axes and by a mean arithmetic rm value of 0 76 indicating that the regional stress regime is transpressional the younger stress regime is characterized by n154 8 e trending 1 and n243 8 e trending 3 axes and by a mean arithmetic rm value of 0 17 indicating a transtensional character for this regional stress regime the low r values of the stress deviators related to the recent stress state reflect normal component slips the earthquake focal mechanism inversions confirm that the younger stress regime continues into the recent the inversion identifies a transtensional stress regime representing strike slip and an extensional stress state with a consistent ne trending hmin 3 axis these stress states are characterized by n66 e and n249 e trending 3 axes respectively both significant regional stress regimes induce left lateral displacement along the southern part of the east anatolian fault eaf or amanos fault the temporal change probably in quaternary time within the regional stress regime from transpression to transtension resulted from the coeval influences of subduction processes in the west southwest i e along the cyprus arc continental collision in the east and westward escape of the anatolian block

the ad 60 denizli basin earthquake and the apparition of archangel michael at colossae aegean turkey this paper illustrates the results of a multidisciplinary study on the active tectonics of hierapolis and colossae in aegean turkey tectonic analysis is combined with a study of historical seismicity highlighting the use of historical sources from oral tradition legends and myths to derive important geological information for which the legendary account is the only witness strong correlation between tectonic and historical mythological data suggests that the legendary narration is based on real geological events this allows a better understanding of the local active tectonics and seismic history at hierapolis it is possible to recognize evidence of surface faulting from the ad 60 earthquake at colossae we can reconstruct the local geomorphic evolution and show its relationship to the ad 60 earthquake in particular cases deciphering local folk tales legends and myths may provide useful data on the historical seismicity of an area this subject has only recently been investigated by geologists bentor 1989 guidoboni 1989 armijo et al 1991 nur 1991 piccardi 2000 2005 but is still complicated because it deals with documents derived from oral tradition many of these documents are based on a codified religious terminology which sounds unfamiliar today and contributes to the lack of precision in specific cases where geological phenomena are clearly quoted geological analysis can be used as an interpretative key of legends this study presents a case history where legendary narrations from the denizli basin aegean turkey fig 1a provide useful geological and palaeoseismological information in particular traditions related to a famous earthquake that occurred in ad 60 and two famous ancient sanctuaries of this area colossae located at the southern margin of the basin and hierapolis about 15 km to the nw are examined fig 1b early christian and medieval legends based on geological events are attached to these two places the apparition of archangel michael at colossae and the apocryphal account of the arrival of st philip at hierapolis both legends were later commemorated by famous sanctuaries that have attracted pilgrims through the centuries moreover at hierapolis the geological basis for these legends constituted the source event for local religious rituals also at an earlier level in the greek roman sanctuary of apollo only sparse descriptions about the effects of the ad 60 earthquake are available in historical documents thus oral tradition is the only source of further information the natural phenomena that led to these legends are coseismic geomorphic effects related to that strong earthquake for which legend is the only existent testimony the cases illustrated here are clear examples of how particular hagiographic legends can constitute quasi historical documents following a tectonic study of the area and review of historical accounts this paper focuses on two main aspects of local myths and geology the first recovers important information to reconstruct the seismotectonic parameters of the ad 60 earthquake in particular identifying its source as being the master fault of the denizli basin and the second gains insight into the true origin of particular legends and the reasons for sacred site selection in addition this multidisciplinary approach sheds light on important developments in the evolution of western religious thought

plio quaternary stress states in ne iran kopeh dagh and allah dagh binalud mountain ranges abstract ne iran including the kopeh dagh and allah dagh binalud deformation domains comprises the northeastern boundary of the arabia eurasia collision zone this study focuses on the evolution of the plio quaternary tectonic regimes of northeast iran we present evidence for drastic temporal changes in the stress state by inversion of both geologically and seismically determined fault slip vectors the inversions of fault kinematics data reveal distinct temporal changes in states of stress during the plio quaternary since 5 ma the paleostress state is characterized by a regional transpressional tectonic regime with a mean n140 10 e trending horizontal maximum stress axis 1 the youngest modern state of stress shows two distinct strike slip and compressional tectonic regimes with a regional mean of n030 15 e trending horizontal 1 the change from the paleostress to modern stress states has occurred through an intermediate stress field characterized by a mean regional n trending 1 the inversion analysis of earthquake focal mechanisms reveals a homogeneous transpressional tectonic regime with a regional n023 5 e trending 1 the modern stress state deduced from the youngest fault kinematics data is in close agreement with the present day stress state given by the inversions of earthquake focal mechanisms according to our data and the deduced results in northeast iran the arabia eurasia convergence is taken up by strike slip faulting along ne trending left lateral and nnw trending right lateral faults as well as reverse to oblique slip reverse faulting along nw trending faults such a structural assemblage is involved in a mechanically compatible and homogeneous modern stress field this implies that no strain and or stress partitioning or systematic block rotations have occurred in the kopeh dagh and allah dagh binalud deformation domains the plio quaternary stress changes documented in this paper call into question the extrapolation of the present day seismic and gps derived deformation rates over geological time intervals encompassing tens of millions of years

neotectonics of the pontides implications for incompatible structures along the north anatolian fault data for the post serravallian neotectonic evolution of the pontides in northern turkey indicate predominant ene wsw shortening with complementary nnw sse extension we present a new fault plane solution for the bartin earthquake 3 september 1968 and compare its mechanism with the movement picture of other neotectonic faults in the pontides and northern greece together with that of the thessaloniki earthquake 20 may 1978 the general strain pattern exhibited by these structures agrees remarkably well with that inferred from early tortonian early pleistocene structures reported from within the north anatolian fault zone which have been interpreted as indicating a possible reversal of the sense of movement along the north anatolian transform fault here we argue that such incompatible structures may be related to the overall e w shortening of anatolia and the southern parts of the black sea resulting from the sideways continental escape from around the african and the arabian promontories rather than to hypothetical reversal of motion along the north anatolian fault for which there is no evidence other than the above mentioned incompatible structures this new model also has important implications for seismicity and earthquake risk in regions contained within the southern part of the black sea plate

syn rift sedimentation and structural development of the gediz and buyuk menderes graben western turkey the buyuk menderes and gediz graben of western turkey developed during miocene to recent extension in the aegean region new mapping of structures and sedimentary lithofacies in exhumed basin fill strata is used to reconstruct the evolution of the graben field evidence shows that extension was primarily accommodated by tilted fault blocks 0 2 0 8 km wide bounded by planar faults with some modification by antithetic faulting the basins are faulted on both margins although they are highly asymmetric with dominant 9footwall9 margins characterized by steeper topography and greater thicknesses of exhumed strata within exhumed graben fill sequences lacustrine axial fluvial and laterally derived sedimentary facies can be identified palaeocurrent orientations divergent wedge geometries and intra basin unconformities all indicate that exposed sediments are syn tectonic the present day map patterns demonstrate that the position of graben bounding faults has migrated basinward with time as a result large scale erosion and recycling of the uplifted basin fill have created extensive footwall derived alluvial fans these displace the axial drainage towards the hanging wall margins away from the locus of greatest subsidence

a new intracontinental transcurrent structure the central anatolian fault zone turkey abstract recent neotectonic studies including remote sensing aerial photographs geological field mapping on various scales and measured stratigraphic section substantiate the existence of a large sinistral intracontinental transcurrent structure which we call the central anatolian fault zone cafz this is an approximately 730 km long 2 km to 80 km wide ne trending active sinistral strike slip fault zone that cuts across the anatolian plateau between duzyayla in the northeast and anamur county in the southwest it continues onward beneath the eastern mediterranean sea and determines the boundary of the antalya and adana basins as far as to the west of cyprus the cafz is a very young neotectonic structure it resulted from the reactivation and propagation of an older paleotectonic structure the so called ecemi s corridor in both nne and sw directions across the inner tauride suture in the plio quaternary times based on geometric discontinuities the cafz is divided into 24 segments each of them is characterized by a number of strike slip morphotectonic features reflecting recent motions the easternmost part of the anatolian platelet is being deformed internally by several dextral to sinistral intraplate strike slip faults these are the lake salt fault zone lsfz the salanda fault sf the cafz the goksu yazyurdu fault zone gyfz and the malatya ovacik fault zone mofz they take up lesser motion and are younger than boundary faults of the anatolian platelet the gyfz and mofz splay from the natf cut across the anatolian platelet and then meet to the eatf whereas other faults are confined into the anatolian platelet and seem to be independent structures however present day structural pattern of all these intraplate faults and boundary faults of the anatolian platelet indicates a regional strain pattern of nnw sse directed shortening and ene wsw directed extension and they seem to have developed to accommodate northward motion of the arabian plate since late early pliocene times

the tectonic development of the hellenic arc and the sea of crete a synthesis abstract we use field analyses together with interpretation of aerial photographs orbital imagery and sea beam data to define more accurately the geometry of fault systems in the hellenic arc the tectonics of the area are dominated by extensional processes related to normal faulting we then use sea beam data previous oceanographic studies and extrapolation of field analyses on surrounding islands to describe the fault pattern of the cretan sea basin which is found consistent with the land fault pattern the mechanisms of the late neogene and quaternary deformation of the central and southern aegean region are analysed in terms of stress trajectories as revealed by field studies of fault populations we then examine the subsidence of the sea of crete in terms of a model of uniform stretching of the lithosphere the opening of the sea of crete was cylindrical and did not result in bending of crete this leads us to modify the southern portion of an earlier kinematic reconstruction of aegea in agreement with recent paleomagnetic results the implications of the opening of the sea of crete on the tectonic evolution of the straits to the west and east of crete are discussed finally the uplift of the outer arc is explained by underplating due to subduction

morphological and microtectonic analysis of quaternary deformation from puna and santa clara islands gulf of guayaquil ecuador south america abstract this paper presents the neotectonic study of santa clara and puna islands sited in the gulf of guayaquil eastern part both islands are located on the south western segment of the fault zone bounding to the east the north andean block fault motion and morphostructural analysis were carried out from pleistocene age terrain a two step deformation characterises the south puna tectonics the first step involves the zambapala cordillera uplift that post dates pleistocene sediments and pre dates a marine terrace correlated with the m i s 11 or 13 440 550 ka the second step is the formation of a pull apart that shows evidence of 2 9 km dextral offset since the m i s 11 or 13 giving an offset mean rate of 5 3 to 6 6 mm yr this rate is higher than the one calculated on the pallatanga fault northeast of the study area in the western andean cordillera suggesting that deformation is split in different fault segments from the gulf of guayaquil to the continent the zambapala cordillera uplift and transpression deformation requires a compressive event that may have been induced by the subduction process during the early pleistocene

late quaternary sea level change sedimentation and neotectonics of the gulf of gokova southeastern aegean sea abstract the sedimentary and tectonic late quaternary evolution of the gulf of gokova located at the southwest anatolia southeastern aegean sea region has been interpreted from 800 line km of 3 5 khz and single channel airgun seismic reflection profiles the older part of the gokova basin is formed by mainly e w trending faults and filled by the latest miocene pliocene quaternary hemipelagic sediments with thickness up to 2 5 km the lycian nappes which primarily cover extreme southwestern anatolia represent the basement rocks for the gokova region younger active faulting so called gokova transfer fault gtf which has not been previously discussed in the literature trends ne in the central part of the gulf of gokova basin and records sinistral strike slip motion broadly parallel to the convergence direction of the aegean anatolian and african plates the continental shelf of the northeastern gulf of gokova is mostly formed by numerous superimposed deltaic successions depositional sequences separated by major erosional unconformities during times of lowered sea level associated with late quaternary glaciations deltas prograded more than 40 km seaward from their present positions foreset progradation terminated with the rise of sea level in interglacial and post glacial times and deltas were relocated far inland these major transgressions resulted in unconformities that are correlated with the beginning of oxygen isotope stages 9 7 5 and 1 and provide chronostratigraphic markers for a detailed analysis of sedimentation patterns in the late quaternary all seismic lines show that the topset to foreset transition of the youngest pleistocene delta system developed around 145 150 ms below present sea level thus the maximum pleistocene sea level lowering 18 000 years bp was about 110 m the positions of maximum regression for isotopic stages 6 8 and 10 were found as 160 190 and 215 m below present sea level respectively paleo shoreline positions during isotopic stages 2 6 and 8 suggest an overall gradual subsidence of gokova basin during the last 0 5 ma in the southeastern aegean sea the seismic sedimentary chronology suggests that the gokova basin is subsiding at 0 3 0 4 mm year three bathymetric low and e w wnw ese directed two main ridges in the gulf area are noticeable from the bathymetric data and are well correlated to the seismic data while the main orientation of the gulf is e w more recent ene wsw and wnw ese structures are remarkable in the western and the mid eastern part of the gulf respectively subsidence rates are greatest in the southern center of the basin and decrease northward so that the northern area is being tilted southward

plate tectonic evolution of the mediterranean middle east region abstract an interpretive model for the mesozoic cenozoic plate tectonic evolution of the mediterranean and adjacent areas is illustrated by a series of paleoposition maps at selected intervals between the late triassic and recent this interval witnessed an important period of tensional development during the triassic and jurassic that fragmented pangea after its late paleozoic consolidation a number of oceanic areas evolved through jurassic time all of which have since been consumed during the alpine orogeny during the cretaceous and tertiary sea floor spreading geometry in the north and south atlantic resulted in convergence between africa and eurasia that controlled the evolution of the mediterranean and adjacent middle east areas from the late mesozoic to recent the interpretation departs from several previous ones in the following respects 1 1 the eastern mediterranean and adjacent middle east area are interpreted to have developed as two seaways with an intervening continental sliver derived from africa that now comprises central turkey and west iran these seaways persisted from the late triassic to late cretaceous by which time they were largely consumed by northward subduction 2 2 spreading that produced the present eastern mediterranean sea developed during the late cretaceous driving the tripolitza eratosthenes iskenderun continental fragments northward from africa to collision with central turkey as the preceding southern arm of the mesozoic tethys sea floor was entirely consumed initial block faulting in this zone occurred during the jurassic and early cretaceous but without subsidence reaching clearly bathyal depths until the cenomanian turonian this differs from the timing of events in the ionian sequence of the pindic nappe of crete which shows a change from shallow carbonate shelf in the triassic to deep basin in the liassic to the north of equivalent platform facies of the tripolitza nappe 3 3 moesia and rhodope are concluded to have been a single plate until a rifting event that started during the late jurassic the balkan mountains are interpreted to represent an alpine inversion of this mesozoic rift system that extended west from the black sea basin 4 4 the eastern carpathian microcontinental sliver is concluded as continuing southward as the serbo macedonian massif that separates rhodope from the vardar zone rather than as rhodope itself 5 5 the scutari pec lineament is considered as representing a major discontinuity between the apulia pannonian plate and adjacent greece and turkey ophiolites to the northwest of this lineament originated in a single oceanic area the vardar zone ophiolites to the southeast of this lineament evolved from two oceanic areas those of interior greece and northern anatolia and the associated ankara melange relating to the vardar zone the former north arm of tethys and the pindos southern anatolia zagros oman ophiolites relating to a former south arm of mesozoic tethys 6 6 based on the history of development of various elements of the alpine system there is a strong suggestion that important dextral movement took place along a major strike slip fault system reaching from the middle east to the central alps between late cretaceous and middle eocene times

neotectonic intersection of the aegean and cyprus tectonic arcs extensional and strike slip faulting in the isparta angle sw turkey abstract the isparta angle and adjacent antalya bay areas constitute an important segment of the eastern mediterranean region located at the intersection of the southward convex aegean and cyprus arcs some recent tectonic maps show the isparta angle as a nw se compressional lineament extending eastwards into the kyrenia range of northern cyprus however fault data from the onshore isparta angle together with offshore shallow seismic reflection data show that the present morpho tectonic setting is dominated by extension the last phase of compression to affect the area studied in the late miocene was accompanied by regional nappe emplacement lycian nappes onshore fault planes measured from fault zones bounding both the limbs and the core of the isparta angle are oriented predominantly ne sw nw se and n s superimposed slickenfibres show that reverse faults were succeeded in turn by right lateral faults then by normal faults the fault phases are dated by stratigraphical and geomorphological evidence reverse faults date from the late miocene or earlier compressional deformation whereas the right lateral faults mainly developed during latest miocene early pliocene normal faulting dominated from the late pliocene recent an interpretation of shallow seismic reflection data shows that antalya bay is characterised by a nw se trending asymmetrical graben system that has continued to be active during the late miocene early pliocene right lateral strike slip resulted from shear along the eastern termination of a zone of extension and rotation that characterises the western aegean this shear was focused in a n s direction by inherited zones of structural weakness in the basement antalya complex the switch to ne sw extension in the late pliocene quaternary relates to a regional change in stress direction throughout the aegean region and was accompanied by strong uplift of the bey da lari region of the taurus mountains bordering the isparta angle in the west the isparta angle is the link between a the extensional province of western turkey bounded to the south by the actively subducting hellenic arc and b the uplifted anatolian plateau bounded to the south by the cyprus subduction zone understanding the miocene to recent tectonic development helps elucidate the kinematics of the region the new structural data presented lend no support for recent suggestions that the isparta angle and antalya bay represent parts of a regional compressional zone related to plate collision

a conjugate strike slip fault system within the extensional tectonics of western turkey summary three main shocks m 1 m 2 and m 3 17 october 2005 at 05 45 utc m w 5 4 17 october at 09 46 utc m w 5 8 and 20 october at 21 40 utc m w 5 9 and their associated after shocks within the gulf of si gacik 50 km southwest of izmir turkey were studied in detail a temporary seismic network deployed during the activity allowed the hypocentre of m 3 and subsequent aftershocks to be determined with high accuracy a relative relocation technique was used to improve the epicentres of m 1 and m 2 all three main shocks have strike slip mechanisms which agree with the linear trends of the aftershock locations two distinct zones were illuminated by the aftershock locations the zones contain clear echelon patterns with slightly different orientations from the trend of the aftershock distribution m 2 and m 3 rup tured along of the eastern rupture zone which aligns n45 e however the strike direction of m 1 is not clearly identified the alignment of the two rupture zones intersect at their southern terminus at an angle of 90 the fault zones form conjugate pair system and static triggering is considered as a probable mechanism for the sequential west to east occurrence of m 1 m 2 and m 3 this earthquake sequence provides seismological evidence for conjugate strike slip faulting co existing within a region dominated by north south extension and well developed east west trending normal faults

superimposed basin formation during neogene quaternary extensional tectonics in sw anatolia turkey insights from the kinematics of the dinar fault zone abstract in the extensional province of sw anatolia the cross cutting relationship between the nw and ne oriented neogene and quaternary basins is an ongoing debate in the understanding of the tectonic evolution of this area in order to contribute to this issue we carried out a structural and kinematic study along the seismogenic nw trending dinar fault zone dfz this structure was initially controlled by the sedimentary and tectonic evolution of the ne oriented neogene baklan acigol and burdur basins and later by the nw oriented quaternary dinar basin on the basis of 1000 structural and kinematic data in conjunction with basin stratigraphy the dfz can be divided into three almost parallel and continuous bands that are a the hangingwall where quaternary sediments are deformed by normal faults with mechanical striations b the inner zone corresponding to the present dinar fault scarp where nw trending normal faults with mechanical striations are dominant and c the outer zone located in the footwall of the structure comprising the area between the fault scarp and undeformed bedrock where faults exhibit variable orientation and kinematics from strike slip to normal dip slip these kinematics are mainly indicated by calcite shear veins and superimposed mechanical striations respectively this suggests that the dfz changed kinematics over time i e the dfz initiated as dominant dextral strike slip to oblique slip fault system and continued with a dominant normal movement therefore we hypothesize that the nw trending dfz was initially a transfer zone during the late miocene pliocene coeval to the sedimentary and structural evolution of the ne trending baklan acigol and burdur basins during the quaternary the dfz representing an already weakened crustal sector played the role of a normal fault system providing the accommodation space for the quaternary dinar basin hydrothermal circulation and volcanism at ne nw trending faults intersection implies structurally driven conduits channeling fluids from depth to surface

role of regional extension and uplift in the plio pleistocene evolution of the aksu basin sw turkey the aksu basin within the isparta angle area of sw turkey documents plio pleistocene crustal processes at the interface between the tauride mountains and the eastern mediterranean sea basin sedimentation began in the late miocene following an earlier history of emplacement of mesozoic allochthonous units antalya complex miocene basin development and localized late miocene compression aksu phase late miocene early pliocene transtension deformed the aksu basin exploiting pre existing zones of structural weakness during early mid pliocene muddy sediments accumulated in a shallow shelf sea 2 and locally thick up to 250 m cool water antalya tufa deposits then followed prior to glacial times initial localized lacustrine carbonate deposition was followed by development of mainly algal carbonates that are thickest in the west the terraced nature of the tufa terraces at 300 250 100 m above present sea level is explained in terms of fluvial processes regional comparisons suggest a two stage history for the aksu basin first late miocene early pliocene transtension and subsidence secondly late pliocene early pleistocene rifting and marginal uplift the overall tectonic setting reflects interplay between supra subduction zone extension and tectonic escape of anatolia westwards towards the aegean

an improved method for determining the regional stress tensor using earthquake focal mechanism data application to the san fernando earthquake sequence the orientations of fault planes and slip directions indicated by a population of earthquake focal mechanisms can be used to determine best fit regional principal stress directions and r 2 1 3 1 a measure of relative stress magnitudes under the assumption of uniform stress in the source region this analysis allows for the possibility that failure occurs on preexisting zones of weakness of any orientation in the inversion we perform a grid search of stress models to find the one which requires the smallest total rotation of all the fault planes that is needed to match the observed and predicted slip directions the method allows for errors in orientations of both the fault planes and slip directions we have an objective means for identifying the more likely of the two possible fault planes from each focal mechanism relative to a given stress model thus we do not face the problem of ambiguity of nodal planes which plagues other analyses of this kind by using a grid search of stress models rather than a linearization scheme we are able to perform a realistic error analysis and thus establish confidence limits for the preferred regional stresses the method can be used to investigate possible stress inhomogeneities during earthquake sequences by analyzing subsets of the data population the technique has been applied to 76 events from the san fernando earthquake sequence for which we have found best fit stresses plunge and azimuth 1 7 187 2 27 281 3 62 84 and r 0 65 the average misfit between this stress model and all the data is about 8 and all but eight of the aftershocks have misfits of less than 20 these values are considerably less than the uncertainty of the focal mechanism determinations therefore significant stress inhomogeneities are not required by the data our analysis does not support the suggestion of a change in stresses during the aftershock sequence as proposed by others on the basis of an apparent change in focal mechanisms

extensional tectonics in neogene and quaternary sequences at the western margin of the axios basin northern greece neogene and quaternary sequences close to the western margin of the axios basin northern greece have been studied to investigate the nature and extent of their neotectonic deformation synsedimentary deformation is indicated by conjugate growth faults and shear zones and by multiple angular unconformities where possible palaeo stress analysis has been carried out and the majority of the synsedimentary faults are shown to be dynamically controlled and to have developed in response to horizontal nne ssw extension this result which is consistent with recent earthquake focal mechanism studies in the region suggests a similarity in the neotectonic evolution of the northern and southern aegean areas during late cenozoic times

deformation of western turkey from a combination of permanent and campaign gps data limits to block like behavior 1 we present a new geodetic velocity field covering western turkey south of the north anatolian fault our velocity field is derived from a combination of continuously recording gps stations operating since 2003 survey type gps measurements carried out in the period 1997 2005 and velocities from reilinger et al 2006 the velocity field indicates that western turkey currently undergoes extension whose rate increases from the anatolia plateau to the aegean coast the overall extension in westernmost turkey is about 20 mm yr making it one of the fastest areas of continental extension in the world we test whether the observed deformation is better represented by the rotation of crustal blocks or by more distributed deformation while no deformation is detected in the central anatolian plateau we observe a deformation field west of the plateau that cannot be explained by block models unless the blocks are so small as to be essentially indistinguishable from a continuum although concentration of strain rates up to 140 nstrain yr are found across the major grabens strain rates above 50 nstrain yr are found throughout western turkey the distributions of topography and crustal thickness in western turkey agree with the distributions expected if the crust there had a constant thickness at 5 ma equal to that of the present central anatolian plateau and had subsequently been thinned at the present day distribution of strain rates our results therefore suggest that extensional strain affects the whole continental lithosphere of western turkey rather than being restricted to a small number of block boundaries

geochemical constraints for the origin of thermal waters from western turkey the combined chemical composition b and sr isotopes and the basic geologic setting of geothermal systems from the menderes massif in western turkey have been investigated to evaluate the origin of the dissolved constituents and mechanisms of water rock interaction four types of thermal water are present 1 a na cl of marine origin 2 a na hco3 type with high co2 content that is associated with metamorphic rocks of the menderes massif 3 a na so4 type that is also associated with metamorphic rocks of the menderes massif with h2s addition and 4 a ca mg hco3 so4 type that results from interactions with carbonate rocks at shallow depths the na cl waters are further subdivided based on br cl ratios water from the cumali seferihisar and bodrum karaada systems are deep circulated seawater br cl sea water whereas water from canakkale tuzla br cl sea water are from dissolution of messinian evaporites good correlations between different dissolved salts and temperature indicate that the chemical composition of the thermal waters from non marine geothermal systems is controlled by 1 temperature dependent water rock interactions 2 intensification of reactions due to high dissolved co2 and possibly hcl gasses and 3 mixing with overlying cold groundwater all of the thermal water is enriched in b the b isotopic composition 11b 2 3 to 18 7 n 6 can indicate either leaching of b from the rocks or b oh 3 degassing flux from deep sources the large ranges in b concentrations in different rock types as well as in thermal waters from different systems suggest the water rock mechanism 87sr 86sr ratios of the thermal water are used to differentiate between solutes that have interacted with metamorphic rocks 87sr 86sr ratio as high as 0 719479 and carbonate rocks low 87sr 86sr ratio of 0 707864

late cenozoic stress field in the cameli basin sw turkey a history of deformation has been determined for the cameli basin located in the western part of the major fethiye burdur fault zone interpreted as the on land continuation of pliny strabo fault system e g eastern boundary of the hellenic arc inversion of fault slip vectors affecting mio pliocene to quaternary formations in the cameli basin in the southwestern segment of the transtensional fethiye burdur fault zone yields two different normal faulting stress regimes characterized by a roughly orthogonal set of extensional axes a nw se n129 19 e 3 axis and a ne sw n50 16 e 3 axis the orientation of fault sets is predominantly around the ne sw direction in the major fethiye burdur fault zone making the extension nw se the mean r values are 0 74 and 0 69 for both extensions indicating a triaxial stress state which is clearly different from radial extension and from transitional to strike slip stress state the nw se extension is probably responsible for the formation of the cameli basin during mio pliocene time in contrast the inversion of focal mechanism solutions of shallow earthquakes occurring within the cameli basin identifies a present day predominantly extensional stress regime characterized by an approximately n s n184 e 3 axis which has an r value of 0 637 indicating a triaxial stress state the nearly orthogonal extensional stress regimes seem to have been acting contemporaneously with each other at different intensities from the mio pliocene onwards in sw turkey this may be attributed to the geodynamic effects related to the subduction of the african plate beneath anatolia diffusing along hellenic and cyprus arcs and in the west southwestward extrusion of anatolia our hypothesis is that the cause of the early nw se extension is the slab pull force due to the subduction process along the cyprus arc considered to be dominant up to plio quaternary the later ne sw to present day n s extension dominant since the plio quaternary is related to the combined forces of the anatolian extrusion and the subduction process along the hellenic arc

neotectonic structures in the area offshore of alacati doganbey and kusadasi western turkey evidence of strike slip faulting in the aegean extensional province abstract about 400 km of new seismic reflection data has been acquired in the study region offshore of alacati doganbey and kusadasi which enables investigation of the active crustal deformation in this region the deformation onshore in western turkey is dominated by crustal extension and clear evidence of this process is also now available from this offshore area however in the onshore area adjacent to this study region evidence of active right lateral strike slip faulting has also previously been observed this strike slip faulting has previously been thought only to accommodate variations in extension between adjacent normal faults however in the offshore area there is considerable evidence of zones of deformation some of which may link to the strike slip faulting onshore suggesting that strike slip faulting may be of greater importance in this region than previously thought

curie point depths based on spectrum analysis of aeromagnetic data west anatolian extensional province turkey the curie point depth map of western anatolia was constituted from spectral analysis of the aeromagnetic data the curie point depth values from 53 overlapping blocks 90 90 km in size have been estimated from the band pass filtered data the slope of the longest wavelength part of the radially averaged log power spectrum divided by the radial frequency produced the depth to the centroid z0 for the deepest crustal block the depth to the top zt was obtained by the slope of the second longest wavelength part of the spectrum from these depths the curie point depth was then calculated by using zb 2z0 zt the curie point depth estimates for western anatolia range between 8 2 and 19 9 km

late quaternary tectonic and sedimentary history of outer izmir and candarli bays western turkey abstract air gun and 3 5 khz seismic profiles from the eastern aegean sea off turkey show that the continental shelf of outer izmir and candarli bays is formed by several superimposed deltaic sequences during times of lowered sea level associated with late quaternary glaciations deltas prograded seaward more than 60 km from their present positions foreset progradation ceased with the rise of sea level in interglacial and post glacial times and deltas were reestablished far inland in drowned river valleys these major transgressions resulted in unconformities within the superimposed prograded delta sequences the most recent three unconformities are correlated with the beginning of oxygen isotope stages 5 3 and 1 and provide chronostratigraphic markers for a detailed analysis of sedimentation patterns in the late quaternary the coastal shelf and basins are subsiding at an average rate of about 1 m per 1000 years this tectonic subsidence manifests itself as widespread normal block faulting which can be related to the pre miocene structural framework of the region

metal deposits in relation to plate tectonics f j sawkins minerals and rocks vol 17 springer berlin 1984 xiv 325 pp 173 figs dm 98 00 approx us 38 10 cloth bound

recent temporal change in the stress state and modern stress field along the north anatolian fault zone turkey summary the north anatolian fault naf is a dextral strike slip fault which runs about 1400 km from east to west from the karliova triple junction to the aegean domain it was active during the plio quaternary as a consequence of the collision between the eurasian and arabian plates the naf intracontinental deformation zone contributes with the sinistral east anatolian fault to the westward extrusion of anatolia as a consequence of the northward drift of arabia the central naf zone forms a northward convex bend where the eastern naf n110 e trending segment extending from karliova is connected to the western naf n75 e trending segment running to aegea analysing the slip occurring in major earthquakes around the naf we show that the present day stress pattern along the naf agrees with stress magnitude and strike variations from east to west the stress regime along the naf is nnw trending hmax 1 transpression in eastern naf this progressively changes westwards to nw trending 1 transtension in central anatolia this lateral variation means a relative decrease of the hmax magnitude which evolves progressively to an extensional regime 1 vertical around the westernmost naf characterized by a nne trending hmin 3 the drastic change in the tendency of the regional stress state in the north anatolian block from compressional to extensional is effective within the central naf bend the stress regime determined by inversion of slip vectors measured on fault planes of various scales confirms the present day transtensional regime in the central part of the naf bend however the fault kinematic analysis of quaternary stress states within the central naf indicates that this stress state was not continuous throughout the quaternary indeed chronologies of fault slip vectors provide evidence for two distinct quaternary regional strike slip stress states within this zone both states have consistent ne and nw trending 3 and 1 axes respectively but have significantly different r values the change in the strike slip stress regime probably occurred in the middle pleistocene the older mean stress state is characterized by a n142 8 e trending 1 a n52 13 e trending 3 and a mean arithmetic rm value of 0 75 which indicates that the regional stress regime is transpressional the younger strike slip regime is characterized by a n142 14 e 1 axis a n52 10 e 3 axis and a mean rm of 0 24 which indicates the transtensional character for this regime the low r values of the stress deviators related to the recent stress state reflect normal component slips these temporal and spatial stress changes along the naf result from the coeval influence of forces due to the aegean subduction in the west and to the northward drift of arabia in the east over these boundary forces shear is superimposed along the naf which accommodates the anatolia extrusion however the timing of the temporal stress change permits the suggestion that the quaternary stress regime variation in north anatolia is mainly due to the influence of the aegean domain

high altitude plio quaternary fluvial deposits and their implication on the tilt of a horst western anatolia turkey abstract this study investigates the origin and regional tectonic implications of high altitude plio quaternary fluvial deposits developed over the bozdag horst which is an important structural element within the horst graben system of western anatolia turkey a total of 23 deposits occur near the modern drainage divide comprising fluvial to occasionally lacustrine deposits the deposits are all elongated in n s direction with a width length ratio of 1 10 the largest of them is of 13 km in length with a maximum observable thickness of about 100 110 m morphological lithological deformational characteristics of these deposits and the drainage system of the area all suggest that the deposits were formed due to uplift and southward tilting of the bozdag horst this tilting which is estimated as 1 2 to 2 2 caused accumulation of the stream load along channels flowing from south to north all the deposits were later dissected by the same streams with the exception of one deposit which still preserves its original lake form these deposits are of quaternary age which corresponds to the latest n s directed extensional tectonic phase in the region

was the 1899 menderes valley earthquake a double earthquake historical and paleosismological constraints abstract september 20 1899 menderes valley earthquake is the last destroying event in the buyuk menderes graben western turkey just proceeding the installation of the earliest seismograms in the world the previous geological studies revealed that this seismic event of estimated mw 6 5 6 7 caused a surface rupture of 50 km between aydin and kuyucak in the center of the graben based on the extremely different positioning of microseismic epicenter of this event in various historical documents we re evaluated the 1899 earthquake with a rather multidisciplinary perspective quantitative earthquake data including fatalities damage and various types of aids were gathered from daily journals and special commission reports of the time these data are corrected with the population statistics and georeferenced for exact determination of the position of the surface rupture we benefited the verbal description in historical documents and witnesses of elder local people furthermore morphological and palaeoseismological investigations were realized in the eastern part of the graben where surface deformations were made mention in historical documents different ground shake related indicators conformably revealed two distinct geographically separated damage zone one at yenipazar and the other at ortakci in the middle and east of the graben respectively trench studies in the west of the ortakci village indicated evidences of a seismic event presumably the 1899 earthquake with 180 cm vertical displacement bimodal distribution damage unrelated to basement lithology and building types and the incoherence between the total surface rupture length and the observed vertical offset and earthquake intensity lead us to conclude that the 1899 menderes valley earthquake was an earthquake doublet occurred in two neighboring segments in very close temporal proximity