role of tectonic sedimentary melange and permian triassic cover units central southern turkey in tethyan continental margin evolution abstract melanges play a key role in the interpretation of orogenic belts including those that have experienced deformation and metamorphism during continental collision this is exemplified by a palaeozoic tectonic sedimentary melange part of the konya complex that is exposed beneath a regionally metamorphosed carbonate platform near the city of konya in central anatolia the konya complex as a whole comprises three units a dismembered latest silurian early carboniferous carbonate platform a carboniferous melange made up of sedimentary and igneous blocks in a sedimentary matrix also known as the halici group or sizma group and an overlying volcanic sedimentary unit earliest permian the palaeozoic carbonates accumulated on a subsiding carbonate platform that bordered the northern margin of gondwana perhaps as an off margin unit the matrix of the melange was mainly deposited as turbidites debris flows and background terrigenous muds petrographic evidence shows that the clastic sediments were mostly derived from granitic and psammitic pelitic metamorphic rocks typical of upper continental crust both extension and contraction related origins of the melange can be considered however we interpret the melange as a carboniferous subduction complex that formed along the northern margin of gondwana related to partial closure of palaeotethys blocks and slices of upper palaeozoic radiolarian chert basic igneous rocks and shallow water carbonates were accreted and locally reworked by gravity processes large up to km sized blocks and slices of shallow water limestone were emplaced in response to collision of the palaeozoic carbonate platform with the subduction zone the overlying volcanic sedimentary unit earliest permian comprises alkaline lava flows interbedded with volcaniclastic debris flows and turbidites volcanogenic shales and tuff the complex as a whole is overlain by shallow water mixed carbonate siliciclastic sediments of mainly late permian age that accumulated on a regional scale shelf adjacent to gondwana successions pass transitionally into lower triassic rift related shallow water carbonates and terrigenous sandstones in the southwest of the area in contrast triassic sediments in the southeast overlie the melange unconformably and pass upwards from non marine clastic sediments into shallow marine calcareous sediments of mid triassic age marking the base of a regional mesozoic carbonate platform during the latest cretaceous early cenozoic the entire assemblage subducted northwards and underwent high pressure low temperature metamorphism and polyphase folding as a part of the regional anatolide unit

strain gradients in zones of ductile thrusting insights from the external hellenides abstract new finite strain data from a thrust sense shear zone which extends for 600 km along strike in the high pressure belt of the external hellenides greece were used to describe the variation of ductile strain with structural distance d from the basal thrust sampling was carried out along four traverses across the central and southeastern parts of the zone the strain ratio in xz sections r xz of 120 samples was obtained using the theta curve the mean object ellipse and the mean radial length methods all methods give very consistent results based on these results four strain profiles were constructed depicting a non linear increase of r xz values with proximity to the basal thrust these profiles in combination with published strain data from the northwestern parts of the zone enabled us to obtain an empirical logarithmic function describing the relationship between r xz and d this function includes only one varying parameter which represents the strain gradient in linear r xz ln d space the value of strain gradient is directly correlated with the strain level in the thrust zone and provides information for strain localization at its base the proposed function may also be used for quantifying the strain profiles of ductile to semi ductile thrust zones in other orogenic belts such as the alps the appalachians and himalaya

palaeomagnetic and geochronological evidence for a major middle miocene unconformity in soke basin western anatolia and its tectonic implications for the aegean region cenozoic convergence between the eurasian and african plates and concurrent slab roll back processes have produced a progressive extension in back arc areas such as the aegean region and western anatolia there is still a long standing controversy as to whether this was a continuous or stepwise process to shed light on this controversy and on the driving mechanism of regional extension we present palaeomagnetic and geochronological results from the soke basin located at the southeastern rim of the izmir balikesir transfer zone our improved geochronology shows that volcanic activity in the region occurred between 11 66 and 12 85 ma middle to late miocene palaeomagnetic data for the soke basin show a c 23 clockwise rotation whereas early miocene data show a c 28 counterclockwise rotation the primary nature of the magnetization is indicated by a positive tilt test the resulting c 51 counterclockwise rotations during the middle miocene signify a major tectonic reorganization during a period when an interruption of exhumation of metamorphic massifs has been reported we suggest that the izmir balikesir transfer zone is the main driver of the reorganization in the region the regional fingerprint of this tectonic reorganization coincides with the acceleration of trench retreat and illustrates the surface impact of tearing of the hellenic slab supplementary material details of 40 ar 39 ar analysis including heating steps and the output pmag file including details of paleomagnetic analysis performed in this study are available at https doi org 10 6084 m9 figshare c 3690871

geochemical constraints on the provenance and depositional setting of sedimentary rocks from the islands of chios inousses and psara aegean sea greece implications for the evolution of palaeotethys the provenance and depositional setting of late palaeozoic and early mesozoic clastic sediments from the eastern aegean archipelago are examined here for the first time using whole rock geochemistry and composition of detrital chrome spinel major and trace element data for late palaeozoic and permo triassic clastic sediments from the lower and upper units of chios are compatible with an acidic to intermediate source minor input of ultra mafic detritus and recycling of older sedimentary components chondrite normalized ree profiles are uniform with light ree enrichments la n yb n c 7 7 negative eu anomalies eu eu c 0 67 and flat heavy ree patterns gd n yb n c 1 5 indicating an upper continental crustal source and or young differentiated arc material detrital chrome spinel from the clastic sediments of chios has cr number cr cr al values between 0 29 and 0 89 and mg number mg mg fe 2 values between 0 24 and 0 70 suggesting a probably mixed ultra mafic source involving ridge peridotites mid ocean ridge type fore arc peridotites and island arc basalts the metasediments from the islands of inousses and psara have similar whole rock chemical signatures to those of chios although no evidence was found for an ultra mafic source we conclude that both the late palaeozoic sediments from the lower and upper units of chios and the metasediments from inousses and psara were deposited in a continental island arc setting until at least late permian times probably at a single palaeotethyan margin they are interpreted to be allochthonous tectonically transported to their present position by late mesozoic to cenozoic orogenic processes

petrogenetic and tectonic inferences from the study of the mt cer pluton west serbia the mt cer pluton serbia is a complex laccolith like intrusion 60 km 2 situated along the junction between the southern pannonian basin and northern dinarides it intrudes palaeozoic metamorphic rocks causing weak to strong thermal effects based on modal and chemical compositions four rock types can be distinguished 1 metaluminous i type quartz monzonite quartz monzodiorite qmzd 2 peraluminous s type two mica granite tmg which intrudes qmzd 3 stra anica granodiorite quartz monzonite gds and 4 isolated mafic enclaves me found only in qmzd 40 k 39 ar dating and geological constraints indicate that the main quartz monzonite quartz monzodiorite body of mt cer was emplaced not later than 21 ma whereas the emplacement ages of the stra anica granodiorite quartz monzonite and two mica granites are estimated at around 18 and 16 ma respectively the mt cer pluton is similar to the mt bukulja pluton some 80 km southwestwards genesis of qmzd cannot be interpreted by fractional crystallization coupled with mixing or assimilation it is best explained by a convection diffusion process between mantle derived minette leucominette magmas and gds like magmas followed by two end member magma mixing the composition of gds rocks suggests that gds like magmas could have formed by melting of lower crustal lithologies similar to amphibolite metabasalts the geochemistry of tmg is reproduced by an assimilation fractional crystallization model with a ratio of rate of assimilation to rate of fractional crystallization of 0 4 using the compositions of the least evolved tmg of the bukulja pluton and adjacent metamorphic rocks as proxies for the parental magma and contaminant respectively the origin and evolution of the mt cer and adjacent mt bukulja plutons provide new constraints on the tertiary geodynamics of the northern dinarides southern pannonian region the quartz monzonite quartz monzodiorite is interpreted as a result of the oligocene post collisional dinaride orogen collapse which included a limited lithosphere delamination small scale mantle upwelling and melting of the lower crust by contrast the two mica granite magmas formed through melting in shallower crustal levels during the extensional collapse in the pannonian area

mirdita zone ophiolites and associated sediments in albania reveal neotethys ocean origin the mirdita ophiolite zone in albania is associated with widespread melanges containing components of up to nappe size we dated matrix and components of the melange by radiolarians conodonts and other taxa the components consist of radiolarites pelagic limestones and shallow water limestones all of triassic age as well as ophiolites triassic radiolarite as a primary cover of ophiolite material proves middle triassic onset of mirdita ocean floor formation the melange contains a turbiditic radiolarite rich matrix radiolaritic flysch dated as late bajocian to early oxfordian it formed as a synorogenic sediment during west directed thrusting of ophiolite and sediment cover nappes representing ocean floor and underplated fragments of the western continental margin the tectonic structures formed during these orogenic events younger kimmeridian or eohellenic orogeny are sealed by late jurassic platform carbonates the geological history conforms with that of the inner dinarides and adjoining areas we therefore correlate the mirdita pindos ophiolite zone with the vardar zone and explain its present position by far distance west directed thrusting

paleogeographic evidence on the jurassic tectonic history of the pontides new paleomagnetic data from the sakarya continent and eastern pontides the jurassic paleogeographic position of the pontides is not well studied because of insufficient paleomagnetic data for this reason a paleomagnetic study was carried out in order to constrain the paleolatitudinal drift of the turkish blocks during the jurassic period a total of 32 sites were sampled from volcanic and volcanoclastic rocks of the lower middle jurassic kelkit formation eastern pontides mudurnu formation sakarya continent and upper jurassic lower cretaceous ferhatkaya formation exposed around amasya region eastern pontides rock magnetic experiments demonstrate that the main ferromagnetic mineral is pseudo single domain titanomagnetite in these rocks paleomagnetic analysis revealed two main components of the natural remanent magnetization during stepwise thermal and alternating field demagnetization the first component is a low coercivity unblocking temperature component with a direction sometimes similar to that of the earth s present field or a viscous component the second component which is interpreted as the characteristic remanent magnetization chrm direction has low to high coercivity properties between 20 and 100 mt or unblocking temperatures between 300 and 580 c a positive fold test at the 95 level of confidence proved that the chrm of the sites is primary paleomagnetic directions calculated for the kelkit formation in the eastern pontides have a mean direction of d 334 8 i 49 7 95 7 1 after tilt correction a mean direction of d 332 2 i 48 5 95 14 6 was obtained from the volcanoclastic rocks of the mudurnu formation and d 324 3 i 43 3 95 9 5 was calculated for the upper jurassic lower cretaceous limestones ferhatkaya formation of the amasya region the jurassic rocks in the eastern pontides and mudurnu region are considered to represent products of the rifted neo tethys ocean while the upper jurassic lower cretaceous sediments in amasya are related to basin filling materials the data suggest that the kelkit formation was formed at 30 5 n paleolatitude and the equivalent mudurnu formation at 29 5 n paleolatitude the paleolatitude of the eastern pontides indicates that this rifting block was separated from eurasia by a marginal basin instead of being a part of eurasia the lower paleolatitude of the amasya region at 24 8 n in the upper jurassic to lower cretaceous clearly indicates southward drift of the turkish blocks during the jurassic to lower cretaceous period together with the motion of eurasia

is there a link between faulting and magmatism in the south central aegean sea a distinct spatial relationship between surface faulting magmatic intrusions and volcanic activity exists in the aegean continental crust in this paper we provide detailed structural observations from key onshore areas as well as compilations of lineament maps and earthquake locations with focal plane solutions from offshore areas to support such a relationship although pluton emplacement was associated with low angle extensional detachments the nne to ne trending strike slip faults also played an important role in localizing the middle miocene plutonism providing ready pathways to deeper magma batches and controlling the late stage emplacement and deformation of granites in the upper crust additionally the linear arrangements of volcanic centres from the quaternary volcanoes along the active south aegean volcanic arc are controlled primarily by ne trending faults and secondarily by nw trending faults these volcanic features are located at several extensional settings which are associated with the main ne trending faults such as i in the extensional steps or relay zones between strike slip and oblique normal fault segments ii at the overlap zones between oblique normal faults associated with an extensional strike slip duplex and iii at the tip zone of a ne trending divergent dextral strike slip zone the ne trend of volcano tectonic features such as volcanic cone alignments concentration of eruptive centres hydrothermal activity and fractures indicates the significant role of tectonics in controlling fluid and magma pathways in the aegean upper crust furthermore microseismicity and focal mechanisms of earthquakes in the area confirm the activity and present kinematics of these ne trending faults

eocene development of the northerly active continental margin of the southern neotethys in the kyrenia range north cyprus we focus on an active continental margin related to northwards subduction during the eocene in which sedimentary melange olistostromes forms a key component maastrichtian early eocene deep marine carbonates and volcanic rocks pass gradationally upwards into a thick succession 800 m of gravity deposits exposed in several thrust sheets the lowest levels are mainly siliciclastic turbidites and debris flow deposits interbedded marls contain middle eocene planktonic benthic foraminifera and calcareous nannofossils sandstones include abundant ophiolite derived grains the higher levels are chaotic debris flow deposits that include exotic blocks of late palaeozoic mesozoic neritic limestone and dismembered ophiolite related rocks a thinner sequence 200 m in one area contains abundant redeposited paleogene pelagic limestone and basalt chemical analysis of basaltic clasts shows that some are subduction influenced basaltic clasts from unconformably overlying alluvial conglomerates late eocene oligocene indicate derivation from a supra subduction zone ophiolite including boninites taking account of regional comparisons the sedimentary melange is interpreted to have formed within a flexurally controlled foredeep floored by continental crust gravity flows including large limestone blocks multiple debris flows and turbidites were emplaced followed by southwards thrust imbrication the emplacement was possibly triggered by the final closure of an oceanic basin to the north alanya ocean further convergence between the african and eurasian plates was accommodated by northwards subduction beneath the kyrenia active continental margin subduction zone rollback may have triggered collapse of the active continental margin non marine to shallow marine alluvial fans prograded southwards during late eocene oligocene time marking the base of a renewed depositional cycle that lasted until latest miocene time

tectonic development of the eastern mediterranean region the eastern mediterranean region is a classic area for the study of tectonic processes and settings related to the development of the tethyan orogenic belt the present set of research and synthesis papers by earth scientist from countries in this region and others provides an up to date interdisciplinary overview of the tectonic development of the eastern mediterrenean region from precambrian to recent key topics include continental rifting ophiolite genesis and emplacement continental collision extensional tectonics crustal exhumation and intraplate deformation e g active faulting alternative tectonic reconstructions of the tethyan orogen are presented and discussed with important implications for other regions of the world the book will be an essential source of information and interpretation for academic researchers geologists and geophysicists advanced undergraduates and also for industry professionals including those concerned with hydrocarbons minerals and geological hazards e g earthquakes

reply to d pană s discussion on the eastern carpathians ophiolites romania remnants of a triassic ocean lithos 108 2009 151 171

lower devonian ostracods from the istanbul area western pontides nw turkey gondwanan and peri gondwanan affinities a lower devonian silicified ostracod fauna has been recovered from limestone interbeds in the buyukdere section of the kozyatagi member of the pendik formation forty one species belonging to 33 genera have been recognized twenty three are already known and 15 are described in open nomenclature one genus and three species omerliella rectangulata gen et sp nov microcheilinella istanbulensis sp nov and roundyella goekchenae sp nov are described silicified larval stages of trilobites agglutinated foraminifers and conodonts co occur with the ostracods the ostracod assemblages are mixed faunas between the epineritic eifelian mega assemblage representative of high energy environments and the basinal thuringian mega assemblage representative of low energy environments the conodont faunas of the pendik formation represent the serotinus patulus and partitus biozones of the late emsian earliest eifelian the emsian ostracods of nw turkey show numerous species level links between the western pontides istanbul terrane and assemblages of contemporaneous faunas of the cantabrian mountains spain morocco and thuringia germany and of similar biofacies this supports the notion that the istanbul terrane armorican terrane collage and northern margins of gondwana were in geographical proximity in late early devonian time

late cenozoic development of the strouma and mesta fluviolacustrine systems sw bulgaria and northern greece abstract the strouma and mesta are two of the largest rivers that drain across sw bulgaria and northern greece into the northern aegean sea their modern valleys flanked by quaternary river terraces are incised into a diverse landscape which records the region s complex tectonic history a network of lacustrine basins existed in the region in the late oligocene to earliest miocene but was disrupted by thrusting and folding related to early miocene transpression this deformation was followed by a period of erosion covering most of the early and middle miocene which probably marked the initiation of the strouma and mesta fluviolacustrine system with geometries unrelated to the older systems the first clear evidence of these river systems dates from the middle miocene late badenian to sarmatian the systems evolved in the late miocene maeotian to early pontian when lakes existed characterized by diatomaceous algae and by occasional burial of abundant plant fragments and coal formation areas in the south south of the kerkini fault were intermittently submerged beneath the aegean sea at this time intense localized uplift of horst blocks in late pontian and pliocene associated with crustal extension resulted in deposition of thick alluvial fans with tilting of sedimentary successions in adjacent grabens evident by the end of the pliocene the highest horsts osogovo rila pirin and belasitsa experienced additional uplift in the pleistocene in part as a result of regional uplift and in part through continued normal faulting pleistocene climate change also resulted in influxes of glacial and fluvioglacial systems the present form of the strouma and mesta fluviolacustrine systems is thus the result of interplay between crustal extension regional uplift and global climate change

late cenozoic surface uplift revealed by incision by the river euphrates at birecik southeast turkey incision by the river euphrates has created a dramatic erosional landscape in the northern arabian platform in se turkey we obtain accurate heights of its terrace deposits in the birecik area using differential gps and summarise evidence regarding heights of late miocene basalt flows and low altitude wetland sediments we thus estimate 600 m of uplift since the early late miocene 9 ma represented by 270 m of fluvial incision the difference reflecting downstream channel lengthening as the coastline has retreated to the persian gulf 1400 km away the oldest recognised sediments inset below this level form a thick aggradation between 100 and 130 m above the present level of the euphrates we estimate that this accumulated during 5 3 ma when uplift rates were low such that aggradation was necessary to maintain a downstream channel gradient in response to the coastal retreat palaeolithic artefacts have been reported locally in euphrates deposits up to 80 m above present river level which we tentatively date to 1 8 ma the euphrates subsequently incised to within 10 m of its present level before aggrading 45 m higher in the late early pleistocene the final 55 m of incision reflects the increase in uplift rates observed worldwide in the early middle pleistocene following the mid pleistocene revolution

the kinematics of central southern turkey and northwest syria revisited central southern turkey nw syria and adjacent offshore areas in the ne mediterranean region form the boundary zone between the turkish african and arabian plates a great deal of new information has emerged in recent years regarding senses and rates of active crustal deformation in this region but this material has not hitherto been well integrated so the interpretations of key localities by different teams remain contradictory we have reviewed and synthesised this evidence combining it with new investigations targeted at key areas of uncertainty this work has led to the inference of previously unrecognised active faults and has clarified the roles of other structures within the framework of plate motions provided by gps studies roughly one third of the relative motion between the turkish and arabian plates is accommodated on the misis kyrenia fault zone which links to the study region from the kyrenia mountain range of northern cyprus much of this motion passes nne then eastward around the northern limit of the amanos mountains as previously thought but some of it splays northeastward to link into newly recognised normal faulting within the amanos mountains the remaining two thirds of the relative motion is accommodated along the karasu valley some of this component steps leftward across the amik basin before passing southward onto the northern dead sea fault zone dsfz but much of it continues southwestward past the city of antakya then into offshore structures ultimately linking to the subduction zone bounding the turkish and african plates to the southwest of cyprus however some of this offshore motion continues southward west of the syrian coast before linking onshore into the southern dsfz this component of the relative motion is indeed the main reason why the slip rate on the northern dsfz measured geodetically is so much lower than that on its southern counterpart in some parts of this region notably in the karasu valley it is now clear how the expected relative plate motion has been accommodated on active faults during much of the quaternary rather than constant slip rates on individual faults quite complex changes in the partitioning of this motion on timescales of hundreds of thousands of years are indicated however in other parts of the region it remains unclear whether additional major active faults remain unrecognised or whether significant relative motions are accommodated by distributed deformation or on the many smaller scale structures present

evolution of the levant margin and western arabia platform since the mesozoic introduction the levant area comprises the offshore levant basin lb eastern corner of the eastern mediterranean as well as the adjacent continental slopes and platforms of the african and arabian plates this area experienced major events of the geodynamical evolution of the middle east such as the late palaeozoic early mesozoic pangea break up the late cretaceous cenozoic closure of the neo tethys and individualization of the arabian plate as well as a set of external factors like global sea level and climate changes this volume combines original data from the offshore and onshore levant in various fields including sedimentology palaeontology sequence stratigraphy geochemistry structural geology stress reconstitution and geophysics seismic lines palaeomagnetism all together these multidisciplinary approaches allow the review of the development of the lb and gain a better insight on the later geological history and deformation processes of the levant provinces the levant describes a composite area that includes 1 the offshore levant basin lb eastern corner of the eastern mediterranean in the west 2 the afro arabian continental slope and platform which is today largely emerged along the eastern mediterranean coast of egypt israel lebanon and syria and in jordan and disrupted by the dead sea fault and 3 the cyprian arc and nw syria collision zones that mark the southern boundary of the eurasian plate fig 1 during the last decades acquisition of geophysical and geological data allowed imaging of the crustal structures and the sedimentary infill of the lb together with detailed tectonic and sedimentary field investigations in the onshore levant these studies discover the basin forming and filling processes modern interpretations indicate that the lb resulted from rifting but much controversy exists on several aspects such as the age and kinematics of its opening or the nature of its crust the late cretaceous to present day period includes several discrete more or less widespread tectonic events in relation with the interaction of the arabian african and eurasian plates that resulted in the division of the levant into several provinces depending on the areas tectonic structures and timing of deformation are more or less constrained the sedimentation patterns observed in the meso cenozoic sequences of the lb and surroundings correlate in a high degree with the tectonic processes however various further factors acted on top such as global sea level or climate changes and the recognition of their relative contribution to the sedimentation processes is a still not finished puzzle this special publication of the geological society of london combines new multidisciplinary datasets acquired recently onshore and offshore levant a special aim of the volume is to demonstrate new concepts on the tectonic stratigraphic sedimentologic and environmental evolution of the lb and african and arabian platforms periods considered cover both the late palaeozoic early mesozoic phase of basin development and the late cretaceous to cenozoic deformation period associated with the closure of neo tethys and the incipience of the dead sea transform middle east basin evolution levant

tectonic transport directions of the lycian nappes in southwest turkey constrained by kinematic indicators abstract the orientation asymmetry and cross cutting relationships of the structures along the contact zone between the lycian nappes and the menderes massif suggest the presence of three deformation phases in the milas region of southwest turkey the first deformation phase d1 is characterized by a ductile deformation with top to the ne sense of shear structural data of the first deformation measured along the uppermost part of the menderes massif and the base of the lycian nappes suggest that the lowermost unit of the lycian nappes was emplaced initially from southwest to northeast onto the menderes massif during the early eocene the second deformation phase d2 is also ductile in nature and is characterized by an e w trending stretching lineation with a bivergent sense of shear which is probably related to the load of the overlying nappes a third deformation phase d3 is characterized by south dipping normal faults with top to the s sense of movement this third deformation phase can be related to southward movement of the lycian nappes along a low angle decollement zone the tectonic contact between the menderes massif and the lycian nappes and their strongly deformed rocks are unconformably covered by approximately flat lying coal bearing early middle miocene sedimentary rocks which constrains the upper time limit for all three deformation phases

a low frequency ice penetrating radar system adapted for use from an airplane test results from bering and malaspina glaciers alaska usa ice thickness measurements are needed to calculate fluxes through fast flowing outlet glaciers in greenland alaska patagonia and antarctica however relatively high attenuation of radio waves by dielectric absorption and volume scattering from englacial water hampers detection of the bed through warm deep ice in the past we have had success measuring ice thickness of temperate glaciers using a ground based monopulse radar system operating at low frequencies 2 mhz here we adapt the same system to operate from an airplane test flights over bering glacier alaska usa detected the bed through ice up to 1250 m thick flights across the seward malaspina glacier system alaska resolved the ice thickness of malaspina glacier but strong hyperbolic shaped returns obscured the bed echo through the seward throat it is likely that this clutter in the signal was caused by off nadir returns from chaotic surface crevasses that are ubiquitous in the throat region

from obduction to continental collision new data from central greece the aim of this paper is to contribute to deciphering the evolutionary history of the hellenides by the study of a large sector of the chain located between the front of the ophiolitic units and the external zones classically attributed to the continental margin of adria in particular the tectonic units located in boeotia a key area located in central greece at the boundary between the internal and external hellenides were studied from structural stratigraphic and biostratigraphic points of view addressing the main debated aspects concerning the origin of the ophiolite nappe s the tectonic evolution of the hellenic orogen was revised with a particular emphasis on the period between obduction and continental collision new findings were compared with consolidated data concerning the main metamorphic events recorded in the more internal hellenides geochemistry and age of the ophiolites and main stratigraphic constraints obtained in other sectors of the belt finally a new reconstruction of the tectonic evolution of this area was introduced and in the context of the dispute concerning the origin of the ophiolitic belts as a possible record of multiple oceanic basins we put forward for consideration a single ocean tectonic model spanning from triassic up to tertiary times and valid for the whole hellenic albanian sector

present day kinematics in the eastern mediterranean and caucasus from dense gps observations abstract the eastern mediterranean and caucasus are located among the eurasian african and arabian plates and tectonic activities are very complex in this paper the kinematics and strain distribution in these regions are determined and investigated from dense gps observations with over 1000 stations and longer observations the elastic block model is used to constrain present day plate motions and crustal deformation the relative euler vectors between the nubian arabian caucasus anatolian and central iranian plates are estimated the arabian eurasia anatolian eurasia nubian eurasia caucasus eurasia and central iranian euler vectors are 0 584 0 1 myr 1 0 825 0 064 myr 1 0 35 0 175 myr 1 0 85 0 086 myr 1 and 0 126 0 016 myr 1 the strain rate in the east mediterranean and caucasus has been estimated from the gps velocity field the results show that the thrust dominated areas the eastern mediterranean middle east caucasus and zagros have negative dilatation and the western anatolia region has positive 2d dilatation rate with significant rotation the west anatolian shows the extension in nw se with about 150 199 nstrain yr in the w e direction the central anatolia shows compression rate below 50 nstrain yr and extensional strain rate adjacent to east anatolian fault and dead sea fault is about 0 100 nstrain yr the contraction strain rate is higher in zagros and caucasus between 100 150 nstrain yr and contraction orientation is along the ne sw direction in caucasus the north part of iran shows less contraction rate below 50 nstrain yr but north east zagros mountains tabriz fault and chalderan fault show extensional rate between 50 110 nstrain yr and principal axes rotation in the n s direction the maximum contraction observed in the kopek dag is about 100 194 nstrain yr and orientated in the ne sw direction east zagros mountain and makran subduction zone have a large clockwise rotation with 70 85 nradian and principal axes remains mostly along the n s direction the observed extension is along n s by about 0 100 nstrain yr with counter clockwise rotation in dead sea fault the sinai block shows shortening rate in the range of 0 100 nstrain yr

neotethyan intraoceanic microplate rotation and variations in spreading axis orientation palaeomagnetic evidence from the hatay ophiolite southern turkey abstract insights into tectonic processes operating in ancient ocean basins are provided by analyses of fragments of oceanic lithosphere preserved as ophiolites during collisional orogenesis here we present a palaeomagnetic analysis of the upper cretaceous hatay kizil dag ophiolite of turkey that provides evidence for intraoceanic microplate rotation and variations in ridge axis orientation in a neotethyan ocean basin magnetizations at 46 sites are shown to be pre deformational in origin and rotated from the relevant reference direction a net tectonic rotation approach to the analysis of the data provides information on permissible net rotation poles and angles and allows uncertainties in input vectors to be considered results demonstrate that all levels of the ophiolite have been rotated anticlockwise by angles in excess of 90 around steeply inclined axes the hatay ophiolite formed in the same supra subduction zone spreading system as the troodos ophiolite cyprus which is known to have rotated 90 anticlockwise in an intraoceanic setting in the late cretaceous to early eocene by considering our results in the context of the known timing of the troodos rotation we infer that 50 60 of rotation of the hatay ophiolite took place as part of an areally extensive troodos microplate this phase of rotation was triggered by initial impingement of the arabian continental margin with the neotethyan subduction trench consistent with models for modern day oceanic microplate rotation in complex convergent plate boundaries the hatay ophiolite then became detached from the actively rotating microplate and was emplaced onto the arabian margin in the maastrichtian undergoing a further 30 40 of anticlockwise rotation during thrusting back stripping of rotations allows correction of the hatay sheeted dykes to their initial orientations the restored dyke trend of 020 differs from that inferred previously for the troodos sheeted dyke complex demonstrating a primary variation in orientation of neotethyan spreading axes such variability is commonly observed in modern spreading systems in marginal basins these may act as analogues for the supra subduction zone spreading inferred for many ophiolites

along strike variations of p t conditions in accretionary wedges and syn orogenic extension the hp lt phyllite quartzite nappe in crete and the peloponnese syn orogenic detachments in accretionary wedges make the exhumation of high pressure and low temperature metamorphic rocks possible with little erosion the velocity of exhumation within the subduction channel or the accretionary complex and thus the shape of p t paths depend upon the kinematic boundary conditions a component of slab retreat tends to open the channel and facilitates the exhumation we document the effect of slab retreat on the shape of p t paths using the example of the phyllite quartzite nappe that has been exhumed below the cretan syn orogenic detachment during the miocene in crete and the peloponnese data show a clear tendency toward colder conditions at peak pressure and during exhumation where the intensity of slab retreat is larger this spatial evolution of p t gradient is accompanied with an evolution from a partly coaxial regime below the peloponnese section of the detachment toward a clearly non coaxial regime in crete

palaeobiogeographical affinity of the early pliensbachian early jurassic brachiopod assemblage of the northern caucasus russia a new evidence abstract brachiopods are useful in detecting the mesozoic palaeobiogeographical affinity of european terranes numerous representatives of this fossil group known from the lower pliensbachian deposits of the northern caucasus southwestern russia allow quantitative assessment of their palaeobiogeographical affinity a total of 175 brachiopod species from the northern caucasus and several other regions bakony germany without the alps hallstatt the pyrenees switzerland without the southern alps the swiss southern alps and western algeria are considered for the purposes of the present study the relationships between the regional assemblages were examined with three similarity indices namely the jaccard index the czekanowski s quantified coefficient and the gower index the results indicate the relatively strong similarity of the early pliensbachian brachiopods of the northern caucasus to those of germany the pyrenees switzerland and western algeria and the strong dissimilarity from the assemblages of the bakony hallstatt and the swiss southern alps these results reveal the affinity of the early pliensbachian brachiopod assemblage of the northern caucasus to the boreal biochore however there are tethyan taxa in this assemblage and thus the latter is of transitional nature palaeogeographical and plate tectonic configurations eustatic fluctuations differences between the regional depositional environments etc may explain the palaeobiogeographical patterns registered in the present study the regional factors might have been especially important because of the moderate to weak global palaeobiogeographical differentiation in the early pliensbachian the concept of the mediterranean microcontinent seems to be also useful for explanation of the early pliensbachian brachiopod provinciality

editorial introduction to geological development of anatolia and the easternmost mediterranean region the present set of 22 papers stems from the 7th international symposium on eastern mediterranean geology that was held in adana turkey 18 22 october 2010 after its initiation in l992 in adana this international conference has been held successively in jerusalem israel in l995 nicosia cyprus in 1998 isparta turkey in 2001 thessalonica greece in 2004 and amman jordan in 2007 the cyprus and thessalonica conferences were followed by substantive publications including one with a focus on cyprus panayides et al 2000 and another mainly concerned with the balkan region robertson mountrakis 2006 a subset of the papers that were presented at the 7th adana meeting together with some others have been prepared and edited for the present volume anatolia and the surrounding region provide an excellent opportunity for the study of fundamental geological processes including rifting seafloor spreading ophiolite genesis and emplacement collision continental assembly and neotectonics this volume should interest a wide cross section of international researchers including those concerned with hydrocarbons mineral deposits and seismic risk and also postgraduate students and advanced undergraduates the papers highlight the role of fieldwork the multidisciplinary nature of much of the current research in the region the role of teamwork and the strong contribution being made by young scientists following an introductory chapter the volume is divided into four sections covering different aspects of the region as a whole the area discussed mainly lies within turkey cyprus and syria section 1 is made up of a small number of papers that are mainly concerned with the pontide belt of northern turkey section 2 is concerned with the geological development of the tauride and anatolide belts of central and southern anatolia especially the triassic jurassic period of rifting and passive margin development and the late cretaceous period of ophiolite genesis and emplacement section 3 is mainly concerned with the formation of sedimentary basins during closure of several mesozoic ocean basins and the related structural development during late cretaceous to pliocene time finally section 4 is devoted to aspects of the structural development of the region mainly during the pliocene quaternary i e neotectonics when the plate configuration was essentially as it is today the area covered by each paper is shown in figure 1 the introduction by robertson et al covers the southern part of anatolia and the adjacent easternmost mediterranean region that was the main subject of the international conference the main focus is on late permian recent time a review of the late precambrian recent geological development of the easternmost mediterranean region is published elsewhere robertson et al 2012 the authors discuss alternative interpretations of the mesozoic cenozoic inter relations of the various crustal units that make up the region in particular they consider whether these should be interpreted as individual microcontinents separated by mesozoic small ocean basins or as parts of larger continental units i e microcontinents the anatolides in the north are generally interpreted as the metamorphosed equivalents of the taurides although different reconstructions exist the anatolides are commonly seen as the northern leading edge of the mesozoic tauride anatolide continent that subducted and underwent high pressure lowtemperature hp lt metamorphism during late cretaceous early cenozoic time the anatolides are divided into two parts namely the hp ltmetamorphosed afyon bolkar dag zone in the south which can be closely correlated with the taurides and the very hp lt tavsanli zone further north which also shows some affinities with the taurides but is less well understood the kirsehir massif is interpreted as a rifted continental block that was separated from a larger tauride continent to the south by a mesozoic oceanic basin known as the inner tauride ocean however uncertainties remain including the reconstruction

a key extensional metamorphic complex reviewed and restored the menderes massif of western turkey article i nfo this paper provides a review of the structure and metamorphism of the menderes massif in western turkey and subsequently a map view restoration of its neogene unroofing history exhumation of this massif among the largest continental extensional provinces in the world is generally considered to have occurred along extensional detachments with a ne sw stretching direction restoration of the early miocene history however shows that these extensional detachments can only explain part of the exhumation history of the menderes massif and that ne sw stretching can only be held accountable for half or less of the

nature and significance of late cretaceous ophiolitic rocks and their relation to the baskil granitic intrusions of the elazig region se turkey

evidence for jurassic subduction from the northern calcareous alps berchtesgaden austroalpine germany the closure of the western part of the neotethys ocean started in late early jurassic the middle to early late jurassic contraction is documented in the berchtesgaden alps by the migration of trench like basins formed in front of a propagating thrust belt due to ophiolite obduction these basins propagated from the outer shelf area hallstatt realm to the interior continent hauptdolomit dachstein platform realm the basins were separated by nappe fronts forming structural highs this scenario mirrors syn orogenic erosion and deposition in an evolving thrust belt active basin formation and nappe thrusting ended around the oxfordian kimmeridgian boundary followed by the onset of carbonate platforms on structural highs starved basins remained between the platforms rapid deepening around the early late tithonian boundary was induced by extension due to mountain uplift and resulted in the reconfiguration of the platforms and basins erosion of the uplifted nappe stack including obducted ophiolites resulted in increased sediment supply into the basins and final drowning and demise of the platforms in the berriasian the remaining early cretaceous foreland basins were filled up by sediments including siliciclastics the described jurassic to early cretaceous history of the northern calcareous alps accords with the history of the western carpathians the dinarides and the albanides where 1 age dating of the metamorphic soles prove late early to middle jurassic inneroceanic thrusting followed by late middle to early late jurassic ophiolite obduction 2 kimmeridgian to tithonian shallow water platforms formed on top of the obducted ophiolites and 3 latest jurassic to early cretaceous sediments show postorogenic character

active tectonics of the alpine himalayan belt between western turkey and pakistan summary over 80 new fault plane solutions combined with satellite imagery as well as both modern and historical observations of earthquake faulting are used to investigate the active tectonics of the middle east between western turkey and pakistan the deformation of the western part of this region is dominated by the movement of continental material laterally away from the lake van region in eastern turkey this movement helps to avoid crustal thickening in the van region and allows some of the shortening between arabia and eurasia to be taken up by the thrusting of continental material over oceanic type basement in the southern caspian mediterranean makran and black sea thus central turkey bounded by the north and east anatolian strike slip faults is moving west from the van region and overrides the eastern mediterranean at two intermediate depth seismic zones one extending between antalya bay and southern cyprus and the other further west in the hellenic trench the motion of northern iran eastwards from the van region is achieved mainly by a conjugate system of strike slip faults and leads to the low angle thrusting of iran over the southern caspian sea the seismicity of the caucasus shows predominantly shortening perpendicular to the regional strike but there is also some minor elongation along the strike of the belt as the causcasus overrides the caspian and black seas the deformation of the eastern part of this region is dominated by the shortening of iran against the stable borders of turkmenistan and afghanistan the north east direction of compression seen in zagros is also seen in north east iran and the kopet dag where the shortening is taken up by a combination of strike slip and thrust faulting large structural as well as palaeomagnetic rotations are likely to have occurred in ne iran as a result of this style of deformation north south strike slip faults in southern iran allow some movement of material away from the collision zone in ne iran towards the makran subduction zone where genuinely intermediate depth seismicity is seen within this broad deforming belt large areas such as central turkey nw iran azerbaijan central iran and the southern caspian appear to be almost aseismic and therefore to behave as relatively rigid blocks surrounded by active belts 200 300 km wide the motion of these blocks can usefully be described by poles of rotation the poles presented in this paper predict motions consistent with those observed and also predict the opening of the gulf of iskenderun ne of cyprus the change within the zagros mountains from strike slip faulting in the nw to intense thrusting in the se and the relatively feeble seismicity in se iran baluchistan this description also explains why the north south structures along the iran afghanistan border do not cut the east west ranges of the makran within the active belts surrounding the relatively aseismic blocks a continuum approach is needed for a description of the deformation even though motions at the surface may be concentrated on faults the evolution of fault systems within the active zones is controlled by geometric constraints such as the requirement that simultaneously active faults do not in general intersect many of the active processes discussed in this paper particularly large scale rotations and lateral movement along the regional strike are likely to have caused substantial complexities in older mountain belts and should be accounted for in any reconstructions of them

oceanic core complexes and ancient oceanic lithosphere insights from iapetan and tethyan ophiolites canada and albania abstract oceanic ridges are extensional environments characterized by brittle to ductile normal faulting and episodic magma supply studies in modern oceanic settings suggest that the interplay of low angle detachments and high angle normal faults locally lead to the exhumation of lower crust and upper mantle peridotites to the seafloor as oceanic core complexes along the mid atlantic ridge core complexes typically occur in inside corners of intersections between the ridge axis and major transform faults the core complexes were exhumed by movement along long lived detachment faults that extend for 10s of km and that are crosscut by high angle normal faults oriented parallel to the rift axis ridge segments with abundant detachments would be characterized by lithosphere having little or no upper crust similar features in ophiolites may also reflect the dominance of amagmatic extension this contribution presents two examples of fossilized oceanic core complexes preserved in the canadian appalachian and albanian dinaride ophiolite belts in the canadian appalachians the southern quebec ophiolites experienced two paleozoic orogenies after their obduction onto the laurentian margin although locally obscured by tectonic fabrics and structures the original relationships between the ophiolitic mantle the overlying plutonic section and onlapping ordovician siliciclastic rocks are well preserved in the thetford mines ophiolite which also shows similarities with lithological and structural features of the mirdita ophiolite where conformable contacts between the sedimentary cover sequence debris flows and flysch deposits and the mantle and crustal sections are superbly exposed the jurassic mirdita ophiolite in albania underlies ca 4000 km2 and was only slightly affected by the tertiary alpine orogeny of eastern europe well exposed sections of the ophiolite suggest that the oceanic mantle was exhumed prior to obduction and locally records the formation of an oceanic core complex mafic cumulates of the mirdita ophiolite have been totally excised in places and exhumation related shear zones are preserved in the krabbi puka massif the shear zones are manifested both within the mantle and at the contact with overlying basalts the ophiolitic sedimentary sequence was deposited on basalts sheeted dykes or gabbros and typically consists of debris flows intercalated with and overlain by slumped oceanic sedimentary rocks the lithological and structural characteristics of both the thetford mines and the mirdita ophiolites are consistent with extensional tectonism crustal excision and lower crust upper mantle exhumation during formation both ophiolites are believed to have originated during asymmetrical oceanic extension in a suprasubduction zone setting with preservation of the upper plate lower plate segments during obduction

eastern mediterranean combined geological geophysical zonation and paleogeodynamics of the mesozoic and cenozoic structural sedimentation stages abstract the eastern mediterranean in the neo tethyan collision zone consists mainly of the mesozoic terrane belt and the adjoining oceanic crust complex of the northern part of the sinai plate the recent discovery of large hydrocarbon deposits has attracted considerable attention to this region combined analysis of gravity magnetic paleomagnetic tectonic structural and paleogeographical data sheds light on the tectonic evolution of this region the kiama paleomagnetic zone of inverse polarity discovered in the oceanic crust of the eastern mediterranean suggests transport along transform faults from the eastern part of the tethys ocean the discrepancy between the terrane belt and the nubian arabian foreland oceanic crust and terrane belt testify to the allochthonous nature of the eastern mediterranean for the first time formation paleogeographical maps of structural stages from the triassic to the neogene quaternary have been compiled the integrated tectono geophysical and paleogeographical specifics of deep zonation call for a reevaluation of regional criteria for oil and gas exploration

rutile chemistry and thermometry as provenance indicator an example from chios island greece abstract in the present study we focused on detrital rutile separated from 12 psammitic samples that belong to three different sedimentary successions carboniferous permo carboniferous permo triassic occurring on chios island greece the ti cr al fe nb zr si and v contents of the rutiles were obtained by electron microprobe analyses to trace their provenance the cr and nb concentrations of the analysed rutile grains show a wide range and indicate that this mineral in the carboniferous succession is mainly derived from metamafic rocks whereas in the permo carboniferous and permo triassic successions stem from a metapelitic source the calculated formation temperatures using the zr in rutile thermometer range from ca 520 to 850 c with hotter rutile being encountered in the permo carboniferous and permo triassic successions this feature together with the rutile chemistry indicate a change in source rock lithology through time which could either reflect an increasing depth of erosion of an exhumed variscan nappe pile of heterogeneous composition in the hinterland or a change in the style of accretion and erosion of different terranes at the southern margin of laurussia during the subduction of a branch of the palaeotethys ocean in the late palaeozoic in general this study underscores the importance of rutile chemistry and thermometry in quantitative single mineral provenance analysis and in chemostratigraphic analysis of clastic sedimentary rocks

late cenozoic uplift of southern italy deduced from fluvial and marine sediments coupling between surface processes and lower crustal flow abstract we investigate the rates and magnitudes of late pliocene pleistocene uplift at key localities in the southern italian regions of basilicata and calabria using fluvial and marine terraces these rates show strong lateral variations reaching maxima of 1 mm a 1 or more in the southern apennines which have uplifted by many hundreds of metres since the late early pleistocene and by well over 1 km since the middle pliocene integrated study has been facilitated by the realisation that altitudes of river terraces in this region require substantial correction for downstream channel lengthening given the rapid coastal progradation that is occurring before they can be compared with altitudes of marine terraces these high rates of uplift and the corresponding rates of subsidence of the sea floor in adjacent offshore localities are explained as consequences of coupling between erosion and sedimentation by induced flow in the lower continental crust this coupling being particularly strong due to the narrowness of the southern part of the italian peninsula numerical modelling indicates that time averaged and spatially averaged erosion rates in this region have been 0 5 mm a 1 since the early middle pleistocene less than the regional uplift rates indicating that the landscape is not in a steady state although southern italy lies within a plate boundary zone along which the african plate is subducting and within which the continental crust is extending the observed vertical crustal motions are nevertheless controlled by surface processes in particular across much of this region crustal extension is shown to be a much less important factor than onshore erosion in driving the observed rates of vertical crustal motion

overview of ophiolites and related units in the late palaeozoic early cenozoic magmatic and tectonic development of tethys in the northern part of the balkan region abstract the northern balkan peninsula including serbia montenegro bosnia croatia and the former yugoslavian republic of macedonia represents an excellent region for the study of tectonic processes related to mesozoic tethyan ophiolite genesis and emplacement we first summarise the main tectonic units of the northern balkan peninsula and then use this information to discuss tectonic processes including rifting sea floor spreading ophiolite genesis and emplacement melange accretion ocean basin closure and collision we then discuss alternative models of ophiolite genesis and emplacement for the region and suggest that multi ocean basin interpretations fit the data better than single ocean basin interpretations rifting of adria gondwana during the triassic created a rift in the south budva zone and opened a triassic oceanic basin further north dinaride ocean occurrences of inferred sub continental mantle lithosphere in the dinaride ophiolite belt e g zlatibor may record extensional exhumation within an ocean continent transition zone bordering the adria dinaride continent this was followed by emplacement together with ophiolites and melange during upper jurassic early cretaceous time upper triassic radiolarites and mid ocean ridge type basalts formed at a spreading ridge after continental break up the oceanic lithosphere of the dinaride ophiolite belt was partly generated above a subduction zone the metamorphic soles of the dinaride ophiolites formed during mid late jurassic mainly based on k ar dating widespread melange that is associated with the ophiolites represents a subduction complex controlled by tectonic accretion and sedimentary reworking in trench and fore arc basin settings a possible cause of jurassic dinaride ophiolite emplacement was collision of a subduction trench with a continental margin further north mesozoic oceanic lithosphere subducted northeastwards present coordinates opening a late jurassic marginal basin in the main vardar zone the dinaride ocean in the south closed during late jurassic early cretaceous time tithonian berriasian deformed oceanic crust melange and magmatic arc rocks further north main vardar zone were transgressed by mainly clastic sediments during the early cretaceous however part of the vardar ocean vardar zone western belt or sava zone remained partially open until latest cretaceous time generally northward subduction within this remnant ocean triggered further supra subduction zone ophiolite genesis during the late cretaceous the ocean closed by the maastrichtian followed by early cenozoic regional scale southward thrusting that locally intercalated older and younger mesozoic ophiolites and melanges future progress particularly depends on determining the crystallisation ages of the ophiolites obtaining better structural data on the direction of initial ophiolite emplacement and unravelling the palaeozoic tectonic development of the eurasian continental margin

rotational deformation in the jurassic mesohellenic ophiolites greece and its tectonic significance abstract the jurassic pindos and vourinos ophiolites in the western hellenides of greece are part of the mesohellenic mafic ultramafic slab underlying the eocene miocene sedimentary basin mesohellenic trough the tectonic incorporation of this oceanic slab into the western edge of the pelagonian subcontinent occurred via trench passive margin collision in the late jurassic much of the tectonic architecture of these ophiolites particularly vourinos was acquired during progressive inhomogeneous deformation associated with the initial displacement of the jurassic oceanic crust from its original igneous environment of formation and its subsequent tectonic emplacement eastward onto the pelagonian margin the heterogeneous deformation in the mantle and crustal sequences of the pindos vourinos ophiolites occurred in ductile ductile brittle and brittle fields synchronously as the jurassic oceanic lithosphere was translated eastward it also resulted in differential horizontal rotations within the displaced oceanic slab areas retaining high temperature diapiric mantle fabric appear to have been passively translated by lower temperature ductile shearing commonly along mylonite zones individual dunite bodies in the harzburgite tectonites indicate movement distances of at least kilometer scale pervasively mylonitic domains within the upper mantle peridotites suggest elongation on the order of five to ten times in the direction of ophiolite emplacement seafloor spreading related high temperature mantle structures within the pindos and vourinos ophiolites are sub parallel imprinted ductile kinematic indicators and ductile shear zones pervasive to the mantle and lower crustal sections in both ophiolites are also sub parallel consistent with the direction of tectonic vergence and appear traceable across the sedimentary overburden of the mesohellenic trough these geometric relations imply that the pindos vourinos ophiolites retain their relative orientations from the time of cessation of ductile deformation within the ophiolitic slab more than 90 anticlockwise horizontal rotation of the vourinos ophiolite seems to have taken place during progressive simple shear deformation associated with the eastward emplacement of the jurassic oceanic lithosphere this kind of rotational deformation postdating the igneous accretion of ancient oceanic crust may be common in many ophiolites and should be carefully distinguished from tectonic extension related vertical rotational deformation developed during their seafloor spreading evolution

successive structural events in the hatay ophiolite of southeast turkey distinguishing oceanic emplacement and post emplacement phases of faulting abstract new structural data are presented and interpreted for the cretaceous hatay ophiolite which was emplaced onto the arabian continental margin during latest cretaceous maastrichtian time although lacking a preserved metamorphic sole a thick serpentinitic basal shear zone provides evidence of emplacement kinematics whilst structures developed in an extensive cenozoic sedimentary cover help to constrain the nature of post emplacement deformation combining field structural measurements with palaeostress analyses enables several discrete structural events to be recognised of which three appear to pre date the cenozoic sedimentary cover the earliest event involved extension parallel to the ophiolitic sheeted dyke complex and relates to oceanic spreading whereas the second and the third events relate to compression and strike slip during intra oceanic displacement or emplacement of the ophiolite onto the arabian continental margin some structures at the base of or within the ophiolite that were previously attributed to sea floor spreading processes e g oceanic detachment faults are more likely to have formed during subsequent ophiolite displacement emplacement and post emplacement formation of the regional hatay graben

late cretaceous infant intra oceanic arc volcanism the central pontides turkey petrogenetic and tectonic implications abstract a tectonic slice of an arc sequence consisting of low grade metavolcanic rocks and overlying metasedimentary succession is exposed in the central pontides north of the izmir ankara erzincan suture separating laurasia from gondwana derived terranes the metavolcanic rocks mainly consist of basaltic andesite andesite and mafic cognate xenolith bearing rhyolite with their pyroclastic equivalents which are interbedded with recrystallized pelagic limestone and chert the metasedimentary succession comprises recrystallized micritic limestone with rare volcanogenic metaclastic rocks and stratigraphically overlies the metavolcanic rocks the geochemistry of the metavolcanic rocks indicates an arc setting evidenced by depletion of hfse ti p and nb and enrichment of fluid mobile lile identical trace and rare earth elements compositions of basaltic andesites andesites and rhyolites suggest that they are cogenetic and derived from a common parental magma the arc sequence crops out between an albian turonian subduction accretionary complex representing the laurasian active margin and an ophiolitic melange absence of continent derived detritus in the arc sequence and its tectonic setting in a wide cretaceous accretionary complex suggest that the kosdag arc was intra oceanic zircons from two metarhyolite samples give late cretaceous 93 8 1 9 and 94 4 1 9 ma u pb ages these ages are the same as the age of the supra subduction ophiolites in western turkey which implies that that the kosdag arc may represent part of the incipient arc formed during the generation of the supra subduction ophiolites the low grade regional metamorphism in the kosdag arc is constrained to 69 9 0 4 ma by 40 ar 39 ar muscovite dating indicating that the arc sequence became part of a wide tethyan cretaceous accretionary complex by the latest cretaceous non collisional cessation of the arc volcanism is possibly associated with southward migration of the magmatism as in the izu bonin mariana arc system

palaeogene alluvial volcaniclastic deposits in the mesta basin sw bulgaria depositional setting and basin evolution the mesta half graben is one in a series of extensional basins in sw bulgaria that record the onset of extension within the rhodope zone in the late eocene tectonic activity on a continuous detachment along the eastern margin was a major control on subsidence accommodation space creation sediment supply and facies distribution in the basin the sedimentary architecture was complicated by synsedimentary rotation the presence of intrabasinal faults and the resulting compartmentalization as well as synsedimentary volcanic activity facies and structural analysis of a key transverse section in the central part of the basin together with supporting observations from other parts of the basin indicate a pulsed tectono sedimentary evolution of the basin with three distinct stages the first stage late eocene is a phase of rapid extension with an initial alluvial setting basin margin fans and an axial fluvial through drainage system were the major depositional systems in this stage the second stage early oligocene marks the onset of volcanic activity within the mesta basin and is characterized by the formation of volcanic centres an intense phase of explosive volcanism and rapid infilling of the previous basin topography with volcanic material deposited from pyroclastic density currents the third stage late oligocene represents waning volcanic activity in a mixed alluvial volcaniclastic environment this stage is characterized by alternating alluvial and volcaniclastic depositional cycles as well as partial reworking of volcanic material

palaeomagnetic insights into the evolution of neotethyan oceanic crust in the eastern mediterranean abstract a synopsis of palaeomagnetic data from three late cretaceous eastern mediter ranean tethyan ophiolites troodos hatay and baer bassit and their sedimentary coversequences is presented these data provide valuable insights into the role of regional andlocal scale tectonic rotations in the geodynamic evolution of neotethyan oceanic crust thegeologically earliest phases of tectonic rotation are documented in the troodos ophiolite where rotations around both subvertical and subhorizontal axes are readily related to thedevelopment of the spreading fabrics and structures during crustal genesis subsequent c 74 anticlockwise intra oceanic rotation of a troodos microplate has been quantified throughanalysis of the in situ sedimentary cover of the troodos ophiolite results indicate that bulkanticlockwise rotation began soon after the cessation of spreading and ended by the end ofthe eocene with c 50 60 of microplate rotation being over by the maastrichtian the timeat which ophiolite thrust sheets were emplaced onto the arabian continental margin to theeast of troodos recent results from the emplaced structurally dismembered baer bassitophiolite indicate extreme anticlockwise rotations of ophiolitic thrust sheets varying on akilometre scale new data from the post emplacement sedimentary cover confirm that onlya small component of these rotations is due to post emplacement tectonism baer bassitrepresents the leading edge of the emplaced ophiolitic sheet new data from the morecoherent section preserved in the hatay ophiolite to the north demonstrate significantanticlockwise rotation this is equivalent to the rotation of the most northerly part of thebaer bassit units to the south and is of the same sense and magnitude as the pre maastrichtian phase of microplate rotation documented in the troodos this suggests acommon intra oceanic origin for the majority of the troodos and hatay rotations and asignificant component of the more variable rotations observed in baer bassit overall therefore the data support a model involving 1 intra oceanic rotation of a coherent regionof crust within the southern neotethyan basin this rotated unit is more areally extensivethan has previously been inferred from consideration of data from the troodos ophiolitealone 2 emplacement of part of the rotated unit onto the arabian platform 3 subsequentlocalized post emplacement modification related to the development of the current plateconfiguration

integrated rock magnetic and mineralogical study of the lower triassic sedimentary rocks from spitsbergen abstract a rock magnetic mineralogical and mossbauer spectroscopy study was undertaken on the lower triassic sediments from the west spitsbergen fold and thrust belt wsftb in svalbard as well as the foreland of this orogen for a thorough recognition of magnetic mineralogy necessary for a better constrained interpretation of paleomagnetic results sem and mossbauer spectroscopy indicate the presence of magnetite and pyrrhotite both most probably of secondary origin but altered clasts of volcanic origin and grains of ilmenite and detrital magnetite are also observed thermomagnetic curves of whole rock samples exhibit paramagnetic behavior whereas ferromagnetic separates indicate the presence of magnetite irm component analysis shows three major contributors magnetite hematite and pyrrhotite to the remanence with ferromagnetic iron oxides the most dominant identified ferromagnetic minerals display a wide range of grain size and magnetic behavior with the domination of psd particles rock magnetic characteristics of both areas are similar but sites in the fold belt were most likely remagnetized whereas those in the foreland carry the primary magnetization the age of remagnetization was estimated as pre eurekan related to rift controlled mesozoic extensional phases of the barents sea shelf clark et al 2014 and or cretaceous injections of dolerites in the svalbard archipelago nejbert et al 2011 as well as early stages of the wsftb formation however triassic remanence might persist in volcanic lithoclasts and detrital magnetite indicated along the wsftb the multicomponent nature of the nrm displaying a broad range of grain size might impede the paleomagnetic interpretation of triassic rocks in spitsbergen

the exhumation of the western greater caucasus a thermochronometric study this study provides 39 new thermochronometric analyses from the western part of the greater caucasus a region in which existing data are extremely limited and of questionable quality the new results are consistent with field studies that identify triassic to middle jurassic cimmerian and oligo miocene alpine orogenic erosional events an inverse relationship between the fission track and depositional ages of oligo miocene sedimentary samples also implies some degree of eocene erosion of the greater caucasus and intermediate sediment storage cooling ages and field relationships within the core of the range west of mt elbrus require 5 km of permo triassic exhumation and restrict the overall amount of cenozoic exhumation to 2 5 km current exhumation rates are typically low and do not support a plio pleistocene increase in climate driven denudation high 1 km ma 1 rates of exhumation are restricted to the southern flank of the range in northwest georgia despite a general lack of significant seismicity within the study region this exhumation peak is close to the largest instrumentally recorded earthquake in the caucasus ms 7 0 this may suggest that exhumation is associated with the decoupling of the sedimentary succession from its crystalline basement in the southern part of the range and the inversion of the largely jurassic fill of the greater caucasus basin rates of exhumation are compatible with this being driven by active shortening further sampling and analysis are required to provide a higher resolution low temperature thermochronology of alpine exhumation to isolate the drivers for palaeogene dziruli massif cooling and uplift and to constrain better the extent of the current localized phase of rapid exhumation

sedimentology and paleoenvironmental evolution of messinian evaporites in the iskenderun hatay basin complex southern turkey abstract messinian evaporites which resulted from the salinity crisis during the final closure of the mediterranean sea are exposed in se turkey these evaporites formed in two isolated sub basins iskenderun arsuz ia and hatay samandag hs which belong to different depositional configurations and tectonic structures the neogene fill of these sub basins consists of a thick sedimentary succession that started with early miocene terrestrial clastics followed by reefs middle miocene and shallow water siliciclastics tortonian early to late miocene and finally messinian evaporates these sub basins accumulated in a diverse range of depositional environments from very shallow to deeper water evaporite facies in the ia sub basin consist of sabkhas saline lagoons and ponds they are mainly represented by chemical deposits such as scattered gypsum nodules and balls nodular bedded gypsum laminated gypsum type a and selenites type s1 evaporites in the hs sub basin mainly consist of detrital gypsum composed of gypsum laminae type b c gypsum arenite rudites and deeper water selenites 20 m and resedimented selenites type s2 which were deposited on a sulfate platform with a slope basin transitional zone secondary gypsum with alabastrine and porphyroblastic textures as well as satin spar veins is commonly associated with the sabkha type evaporites of the ia sub basin deeper water clastic evaporites of the hs sub basin have generally remained as primary gypsum or have only been slightly affected by diagenetic alterations the isotope values 87 86 sr 18 o smow and 34 s cdt from the different kinds of gypsum lithofacies of the sub basin are similar to those of the messinian evaporites in other peri mediterranean basins indicating an origin from marine water without external or basinal contributions the messinian evaporites examined in this paper are overlain by early pliocene zanclean deposits composed of shallow and deep water siliciclastics and carbonates with local intercalations of lago mare type strata throughout the messinian evaporitic stage the ia sub basin was mainly comprised of shallow water evaporites while the hs sub basin underwent deepening related to regional tectonics induced by the dead sea fault during the construction of the hatay graben

tectonic evolution of leros island dodecanese greece and correlations between the aegean domain and the menderes massif the history of subduction below the aegean region and western anatolia is hampered by a lack of comprehension of the correlations between the cyclades and the menderes massif the dodecanese archipelago key for this discussion has received very little attention so far this study is focused on the island of leros where two tectono metamorphic units can be observed the upper marina unit and the lower temenia unit the field study including new field mapping and structural observations reveals that temenia unit has been exhumed under marina unit through a top to the ne ductile shearing followed by a top to the sw brittle deformation cutting the temenia marina contact the description of metamorphic aragonite and blue amphibole complemented by rscm thermometry reveals that temenia unit has been buried down to at least 20 km along a cold metamorphic gradient in terms of lithology and paleogeographic affinities the cover of marina unit is similar to the lycian nappes that rest on top of the menderes massif and belong to the northern margin of the pelagonian domain temenia unit can then be compared to lower cycladic blueschists nappe which could in turn be correlated with the cover of the menderes massif which has also recorded a hp lt metamorphic overprint

evidence from the kyrenia range cyprus of the northerly active margin of the southern neotethys during late cretaceous early cenozoic time sedimentary geology and planktonic foraminiferal biostratigraphy have shed light on the geological development of the northern active continental margin of the southern neotethys in the kyrenia range following regional triassic rifting a carbonate platform developed during jurassic cretaceous time followed by its regional burial deformation and greenschist facies metamorphism the platform was exhumed by late maastrichtian time and unconformably overlain by locally derived carbonate breccias passing upwards into upper maastrichtian pelagic carbonates in places the pelagic carbonates are interbedded with sandstone turbidites derived from mixed continental basic volcanic neritic carbonate and pelagic lithologies in addition two contrasting volcanogenic sequences are exposed in the western central kyrenia range separated by a low angle tectonic contact the first is a thickening upward sequence of campanian lower maastrichtian pelagic carbonates silicic tuffs silicic lava debris flows and thick bedded to massive rhyolitic lava flows the second sequence comprises two intervals of basaltic extrusive rocks interbedded with pelagic carbonates the basaltic rocks unconformably overlie the metamorphosed carbonate platform whereas no base to the silicic volcanic rocks is exposed additional basaltic lavas are exposed throughout the kyrenia range where they are dated as late maastrichtian and late paleocene middle eocene in age in our proposed tectonic model related to northward subduction of the southern neotethys the kyrenia platform was thrust beneath a larger tauride microcontinental unit to the north and then was rapidly exhumed prior to late maastrichtian time pelagic carbonates and sandstone turbidites of mixed largely continental provenance then accumulated along a deeply submerged continental borderland during late maastrichtian time the silicic and basaltic volcanogenic rocks erupted in adjacent areas and were later tectonically juxtaposed the campanian early maastrichtian silicic volcanism reflects continental margin type arc magmatism in contrast the upper maastrichtian and paleocene middle eocene basaltic volcanic rocks erupted in an extensional or transtensional setting likely to relate to the anticlockwise rotation of the troodos microplate

late cretaceous early eocene tectonic development of the tethyan suture zone in the erzincan area eastern pontides turkey six individual tectonostratigraphic units are identified within the izmir ankara erzincan suture zone in the critical erzincan area of the eastern pontides the ayikayasi formation of campanian maastrichtian age is composed of bedded pelagic limestones intercalated with polymict massive conglomerates the ayikayasi formation conformably overlies the tauride passive margin sequence in the munzur mountains to the south and is interpreted as an underfilled foredeep basin the refahiye complex of possible late cretaceous age is a partial ophiolite composed of 75 by volume serpentinized peridotite mainly harzburgite 20 diabase and minor amounts of gabbro and plagiogranite the complex is interpreted as oceanic lithosphere that formed by spreading above a subduction zone unusual screens of metamorphic rocks e g marble and schist locally occur between sheeted diabase dykes the upper cretaceous karayaprak melange exhibits two lithological associations 1 the basalt radiolarite serpentinite association including depleted arc type basalts 2 the massive neritic limestone lava volcaniclastic association that includes fractionated intermediate composition lavas and is interpreted as accreted neotethyan seamount s the several kilometre thick karadag formation of campanian maastrichtian age is composed of greenschist facies volcanogenic rocks of mainly basaltic to andesitic composition and is interpreted as an emplaced upper cretaceous volcanic arc the campanian early eocene sutpinar formation 1500 m thick is a coarsening upward succession of turbiditic calcarenite sandstone laminated mudrock volcaniclastic sedimentary rocks that includes rare andesitic lava and is interpreted as a regressive forearc basin the late paleocene eocene sipikor formation is a laterally varied succession of shallow marine carbonate and siliciclastic lithofacies that overlies deformed upper cretaceous units with an angular unconformity structural study indicates that the assembled accretionary prism supra subduction zone type oceanic lithosphere and volcanic arc units were emplaced northwards onto the eurasian margin and also southwards onto the tauride gondwana related margin during campanian maastrichtian time further mainly southward thrusting took place during the eocene in this area related to final closure of tethys our preferred tectonic model involves northward subduction supra subduction zone ophiolite genesis and arc magmatism near the northerly eurasian margin of the mesozoic tethys

imaging a relic of complex tectonics the lithosphere asthenosphere structure in the eastern mediterranean the crust and upper mantle structure of the eastern mediterranean is investigated through the nonlinear inversion of raleigh wave dispersion curves extracted from broadband records in the region along two profiles crossing the hellenic and cyprian arcs corresponding density models are constructed consistent with the observed gravity anomalies the modelled profiles exhibit a continental crust type overlain by a thick sedimentary cover and underlain by a thick lithospheric mantle the lithosphere asthenosphere system exhibits features which suggest the presence of upducted asthenosphere exhumed to the north of the hellenic arc where the slab extension is limited to depths of about 220 km

quantitative dating of pleistocene deposits of the kyrenia range northern cyprus implications for timing rates of uplift and driving mechanisms the kyrenia range underwent tectonically driven uplift during the pliocene to pleistocene in response to the interaction of various tectonic processes to understand the tectonic processes driving the uplift and how this is related to uplift of other areas of the eastern mediterranean uranium series disequilibrium and optically stimulated luminescence dating were applied to marine and non marine terrace deposits exposed on the northern flank of the range palaeomagnetism and strontium isotope dating were used in conjunction to date the final stages of the marine environment adjacent to the kyrenia range prior to major surface uplift uplift rates range from 1 2 mm a 1 inferred during the early pleistocene to 1 during the late pleistocene the new data show that the kyrenia range was uplifted contemporaneously with the troodos massif in southern cyprus the uplift of the kyrenia range appears to have been significantly faster than that affecting other comparable regions in the easternmost mediterranean during the pleistocene e g lebanon coast southern anatolian plateau the driving mechanism for the uplift of both the kyrenia range and the troodos massif is inferred to be the collision of the eratosthenes seamount with the cyprus trench to the south of cyprus supplementary material details of the methods used are available at https doi org 10 6084 m9 figshare c 3260977