cosmogenic nuclides in the kirin chondrite abstract radioactive and stable cosmogenic nuclides have been determined in the various fragments of the kirin chondrite h5 experimental results obtained from our samples are described and compared with similar data obtained in other laboratories cosmogenic 54 mn 22 na 60 co 26 al 53 mn 40 k in the metal phase and light noble gases were measured based on these data the irradiation history of this meteorite can be explained in terms of 1 a multi stage exposure which involves a first stage irradiation for 10 7 years and a second stage for about 4 10 5 years and 2 depth effects in the productions of the nuclides in 4 second stage and 2 first stage geometries these conclusions are consistent with those of our previous work which was based on a limited number of samples

sedimentary development of the oligocene karsanti basin southern turkey in its regional tectonic setting abstract following late cretaceous ophiolite and melange emplacement within the tauride belt several neogene sedimentary basins of variable size were formed along the southern flank of the taurus continent in southern turkey these include the pozanti and karsanti basins and the regional scale cukurova basin complex extending southwestwards into the cilicia kyrenia basin the karsanti basin is bounded by the regional scale sinistral ecemis fault zone to the west the east anatolian fault zone to the southeast and the negoene adana basin to the south deformed palaeozoic and mesozoic rock units that display an irregular palaeotopography form the basement of the karsanti basin these units are overlain by an allochthonous kizildag melange and by thrust slices of basic ultrabasic ophiolitic rocks farasa ophiolites that were emplaced in this region during the late maastrichtian the karsanti basin was formed during the oligocene above the thrust sheets the karsanti basin disconformably overlies the ophiolitic nappes and is interpreted as a n s trending half graben which was probably most active following the deposition of lacustrine sediments during the late oligocene the main karsanti basin infill is represented by four lithological units 1 alluvial fan deposits a1 2 shallow marine deposits a2 3 lacustrine deposits a3 and 4 fluvial deposits a4 these sediments were deposited during the oligocene prior to the initiation of the main adana basin which formed in a separate intermontane setting the karsanti basin fill is unconformably overlain by early miocene sediments of the neogene adana basin

global positioning system measurements of present day crustal movements in the arabia africa eurasia plate collision zone we present and interpret global positioning system gps measurements of crustal motions for the period 1988 1994 at 54 sites extending east west from the caucasus mountains of southern russia georgia and armenia to the aegean coast of turkey and north south from the southern edge of the eurasian plate pontus block to the northern edge of the arabian platform viewed from a eurasia fixed reference frame sites on the northern arabian platform move n38 13 w at 20 3 mm yr roughly consistent with the velocity implied by nuvel 1a circuit closure n23 7 w at 24 2 mm yr the motion of arabia appears to be transferred directly to the region of turkey north of the suture however eastern turkey is characterized by distributed deformation while central western turkey is characterized by coherent plate motion involving westward displacement and counterclockwise rotation of the anatolian plate internal deformation within the central part of the anatolian plate is less than 2 mm yr the anatolian plate is decoupled from eurasia along the right lateral strike slip north anatolian fault naf this different response in eastern and western turkey to the collision of arabia may result from the different boundary conditions the hellenic arc forming a free boundary to the west and the asian continent and oceanic lithosphere of the black and caspian seas forming a resistant boundary to the north and east we derive a best fitting euler vector for anatolia eurasia motion of 29 2 0 8 n 32 9 0 4 1 3 0 1 m y the mapped surface trace of the naf corresponds well to a small circle about this pole the new euler vector implies an upper bound for naf slip rate of 30 2 mm yr i e assuming all relative motion is accommodated along the naf using the nuvel 1a euler vector for arabia eurasia and the gps euler vector for anatolia eurasia we determine an arabia anatolia euler vector of 31 2 n 45 2 e 0 9 0 1 m y and an upper bound on the east anatolian fault slip rate of 15 3 mm yr the aegean trough region of western turkey deviates significantly from coherent plate rotation in addition to rotating with anatolia this region shows roughly n s extension at a rate of 14 5 mm yr taken together with satellite laser ranging results along the hellenic arc the contemporary pattern of deformation indicates increasing motions toward the arc suggesting that the westward displacement and counterclockwise rotation of anatolia is driven both by pushing from the arabian plate and by pulling or basal drag associated with the foundering african plate along the hellenic subduction zone

confined deep water system development on the accretionary wedge miocene kahramanmaras foreland basin s turkey abstract according to theoretical studies the foreland basin consists of accretionary wedge including wedge top or piggyback basin foredeep forebulge and backbulge depozones all of them are parallel to the orogenic belts of the overlying and underlying plates the closure of the southern branch of the neotethys during the late cretaceous led to an oblique collision of the arabian plate and the anatolide taurides platform leading to the development of the miocene kahramanmaras foreland basin kfb thus the promontory shape of the arabian plate prevented the development of an accretionary wedge parallel to the orogenic belt the accretionary wedge of the kfb includes blocks of various sizes and age mainly mesozoic limestone scattered within an early tertiary matrix mass wasting deposits and shallow to deep marine sediments at the beginning of the miocene transtensional tectonism led to the development of half graben basins on top of the accretionary wedge these basins namely the tekir and cukurhisar also cut the foredeep of the kfb obliquely in contrast with the theoretical study this paper focuses on the evolution and fillings of those basins initially claystone and basin margin reef deposits filled the half graben basins as a consequence of the lower miocene sea invasion then long and narrow conglomeratic channels starting from the northern edge of the basins fan delta progressed southwards passing into sandy lobes then into claystones an activation of the boundary faults of the wedge top basin stopped the progression of the lower middle miocene sediments and led to their deformation then the sedimentation of the kfb shifted towards the basin centre during the middle miocene

miocene transgression in the central and eastern parts of the sivas basin central anatolia turkey and the cenozoic palaeogeographical evolution we present here a reappraisal of the tectonic setting stratigraphy and palaeogeography of the central part of the sivas basin from palaeocene to late miocene the sivas basin is located in the collision zone between the pontides southern eurasia and anatolia a continental block rifted from gondwana the basin overlies ophiolites that were obducted onto anatolia from tethys to the north the central anatolian crystalline complex cacc experienced similar ophiolite obduction during campanian time followed by exhumation and thrusting onto previously emplaced units during maastrichtian time to the east crustal extension related to exhumation of the cacc created grabens during the early tertiary including the sivas basin the sivas basin underwent several tectonic events during paleogene neogene the basin fill varies with several sub basins each being characterised by a distinctive sequence especially during oligocene and miocene evaporite deposition in the central part of the basin during early oligocene was followed by mid late oligocene fluvio lacustrine deposition the weight of overlying fluvial sediments triggered salt tectonics and salt diapir formation lacustrine layers that are interbedded within the fluviatile sediments have locally yielded charophytes of late oligocene age emergent areas including the pre existing sivas basin and neighbouring areas were then flooded from the east by a shallow sea giving rise to a range of open marine sub basins coralgal reef barriers and subsiding restricted marine sub basins utilising new data from foraminifera molluscs corals and nannoplankton the age of the marine transgression is reassessed as aquitanian specifically age diagnostic nannoplankton assemblages of classical type occur at the base of the transgressive sequence however classical stratigraphic markers have not been found within the planktic foraminiferal assemblages even in the open marine settings in the restricted marine sediments there are rich planktic foraminiferal assemblages of classical type but these are of little use in stratigraphy in contrast the gastropod fauna indicate a burdigalian age sediment reworking in the restricted marine environments precludes stratigraphic determination in such environments micro and nano organisms experienced atypical developmental conditions the small benthic foraminifera and associated ostracod assemblages are good indicators of salinity which varied considerably within the restricted marine sub basins some of the corals within the coralgal reefs barriers are also dated as aquitanian a combination of the salt tectonics and the late miocene north westward verging thrusting created the present basin complexity

tectonics and magmatism in turkey and the surrounding area this volume contains 23 papers from a range of international contributors describing recent research into the tectonics and magmatism of turkey and its surroundings this region is sited at the collision zone between eurasia and afro arabia and as such provides an extraordinarily complete and well exposed record of the staged tectonic evolution of this sector of the alpine himalayan orogen the geological history of this area involves separation of continental fragments from the margin of gondwana their migration across the tethyan oceans the subsequent closure of these oceans and finally the development of the neotectonic regime which continues to evolve to the present day such a comprehensive record is relevant to the understanding of collisional zones worldwide the volume is divided into five sections tethyan evolution neotethyan ophiolites post tethyan basin evolution neotectonics and igneous activity the first two sections deal with tethyan oceans whose growth and subsequent closure dominated the geodynamic framework in the mesozoic and cenozoic the subsequent sections deal with more recent geological developments from the balkan peninsula in the west to the transcaucasus in the east that followed consumption of the tethyan oceans there is a broad mix of papers throughout the volume wide ranging review papers on ocean development and extensional tectonics are followed by detailed descriptions of petrology and geochemistry and geographically focused studies on basin evolution specific aspects of extensional and strike slip tectonics and discussions of the relationship of magmatic activity to the tectonic development of the area tectonics and magmatism in turkey and the surrounding area presents up to date results and ideas from a large number of international contributors on a wide range of current research activity in this region it is essential reading for all geoscientists with an interest in both academic and applied aspects of eastern mediterranean geology

hematite u th he thermochronometry constrains intraplate strike slip faulting on the kuh e faghan fault central iran abstract the kuh e faghan strike slip fault system kff located to the northern edge of the lut block in central iran developed through a neogene quaternary pulsed history of eastward fault propagation and fault related exhumation this system is a consequence of the residual stresses transmitted from the arabia eurasia convergent plate boundary here we integrate structural and textural analysis with new and previously published apatite fission track aft and apatite u th he apatite he results chlorite thermomentry and hematite u th he data from hematite coated brittle fault surfaces to constrain the timing of tectonic activity and refine patterns of late miocene pliocene burial and exhumation associated with the propagation of the kff twenty nine hematite u th he hematite he dates from three striated hematite coated slip surfaces from the kff fault core and damage zone yield individual dates from 12 2 ma petrographic analysis and chlorite thermometry of a polyphase fossil fluid system in the kff fault core document that fluid circulation and mineralization transitioned from a closed system characterized by pressure solution and calcite growth to an open system characterized by hot hydrothermal t 239 10 c fluids and hematite formation hematite microtextures and grain size analysis reveal primary and secondary syntectonic hematite fabrics no evidence of hematite comminution and similar hematite he closure temperatures 60 85 c in each sample integration of these results with thermal history modeling of aft and apatite he data shows that kff activity in the late miocene is characterized by an early stage of fault nucleation fluid circulation hematite mineralization and eastward propagation not associated with vertical movement that lasted from 12 to 7 ma hematite he aft and apatite he data track a second phase of fault system activity involving fault related exhumation initiating at 7 ma and continuing until present time our new data constrain the onset of the recognized late miocene pliocene tectonic reorganization in north central iran

the berit transect of the tauride thrust belt s turkey late cretaceous early cenozoic accretionary collisional processes related to closure of the southern neotethys abstract we report on an integrated study of a critical segment of the tauride thrust belt in se turkey berit area units related to two sutures are exposed in the northerly and southerly parts of the area studied in the north the upper cretaceous binboga melange reflects the closure of a northerly mesozoic oceanic basin in the south contrasting units document the closure of the southern neotethys in the south the berit or goksun ophiolite formed as an incipient oceanic arc within the southern neotethys during the late cretaceous c 90 ma intercalated amphibolite granulite facies rocks may record a dismembered metamorphic sole an underlying meta sedimentary meta volcanic unit is interpreted as accreted continental rift and oceanic seamount lithologies the berit ophiolite was accreted to the tauride active continental margin to the north around 85 ma and was then intruded by calc alkaline granites c 70 85 ma northerly margin units were exhumed and covered by shelf carbonate sediments during latest cretaceous early cenozoic time northward subduction during the mid cenozoic c 45 ma resulted in back arc extension along the tauride active margin and subduction influenced volcanism possibly controlled by slab roll back during oligocene early miocene time the southern neotethys closed and the tauride active margin was telescoped to create the present south vergent thrust stack this was accompanied by mass wasting of the advancing allochthon to form sub aqueous frontal olistostromes the arabian platform was over ridden by mid miocene time followed by left lateral strike slip along the east anatolian fault zone as anatolia began to escape westwards towards the aegean sea

the misis andirin complex a mid tertiary melange related to late stage subduction of the southern neotethys in s turkey abstract the mid tertiary mid eocene to earliest miocene misis andirin complex documents tectonic sedimentary processes affecting the northerly active margin of the south tethys neotethys in the easternmost mediterranean region each of three orogenic segments misis in the sw andirin central and engizek in the ne represent parts of an originally continuous active continental margin a structurally lower volcanic sedimentary unit includes late cretaceous arc related extrusives and their lower tertiary pelagic cover this unit is interpreted as an early tertiary remnant of the mesozoic south tethys the overlying melange unit is dominated by tectonically brecciated blocks 100 m across of mesozoic neritic limestone that were derived from the tauride carbonate platform to the north together with accreted ophiolitic material the melange matrix comprises polymict debris flows high to low density turbidites and minor hemipelagic sediments the misis andirin complex is interpreted as an accretionary prism related to the latest stages of northward subduction of the south tethys and diachronous continental collision of the tauride eurasian and arabian african plates during mid eocene to earliest miocene time slivers of upper cretaceous oceanic crust and its early tertiary pelagic cover were accreted while blocks of mesozoic platform carbonates slid from the overriding plate tectonic mixing and sedimentary recycling took place within a trench subduction culminated in large scale collapse of the overriding northern margin and foundering of vast blocks of neritic carbonate into the trench a possible cause was rapid roll back of dense downgoing mesozoic oceanic crust such that the accretionary wedge taper was extended leading to gravity collapse melange formation was terminated by underthrusting of the arabian plate from the south during earliest miocene time collision was diachronous in the east engizek range and se anatolia collision generated a lower miocene flexural basin infilled with turbidites and a flexural bulge to the south miocene turbiditic sediments also covered the former accretionary prism further west misis range the easternmost mediterranean remained in a pre collisional setting with northward underthrusting incipient subduction along the cyprus arc the lower miocene basins to the north misis and adana indicate an extensional to transtensional setting the ne sw linking segment andirin probably originated as a mesozoic palaeogeographic offset of the tauride margin this was reactivated by strike slip and transtension during later tertiary diachronous collision related to on going plate convergence the former accretionary wedge upper plate was thrust over the lower miocene turbiditic basins in mid late miocene time the plio quaternary was dominated by left lateral strike slip along the east anatolian transform fault and also along fault strands cutting the misis andirin complex

oceanic crust generation in an island arc tectonic setting se anatolian orogenic belt turkey a number of late cretaceous ophiolitic bodies are located between the metamorphic massifs of the southeast anatolian orogenic system one of them the goksun ophiolite northern kahramanmaras which crops out in a tectonic window bounded by the malatya metamorphic units on both the north and south is located in the ew trending nappe zone of the southeast anatolian orogenic belt between goksunand afsin northern kahramanmaras it consists of ultramafic mafic cumulates isotropic gabbro a sheeted dyke complex plagiogranite volcanic rocks and associated volcanosedimentary units the ophiolitic rocks and the tectonically overlying malatya keban metamorphic units were intruded by syn collisional granitoids 85 ma the volcanic units are characterized by a wide spectrum of rocks ranging in composition from basalt to rhyolite the sheeted dykes consist of diabase and microdiorite whereas the isotropic gabbros consist of gabbro diorite and quartzdiorite the magmatic rocks in the goksunophiolite are part of a co magmatic differentiated series of subalkaline tholeiites selective enrichment of some lil elements rb ba k sr and th and depletion of the hfs elements nb ta ti zr relative to n morb are the main features of the upper crustal rocks the presence of negative anomalies for ta nb ti the ratios of selected trace elements nb th th yb ta yb and normalized ree patterns all are indicative of a subduction related environment all the geochemical evidence both from the volcanic rocks and the deeper levels sheeted dykes and isotropic gabbro show that the goksun ophiolite formed during the mature stage of a suprasubduction zone ssz tectonic setting in the southern branch of the neotethyan ocean between the malatya keban platform to the north and the arabian platform to the south during late cretaceous times geological geochronological and petrological data on the goksun ophiolite and the baskil magmatic arc suggest that there were two subduction zones the first one dipping beneath the malatya keban platform generating the baskil magmatic arc and the second one further south within the ocean basin generating the goksun ophiolite in a suprasubduction zone environment

geodynamic significance of granitoid magmatism in the southeast anatolian orogen geochemical and geochronogical evidence from goksun afsin kahramanmaras turkey region in southeast anatolia there are number of tectonomagmatic units in the kahramanmaras malatya elazig region that are important in understanding the geological evolution of the southeast anatolian orogenic belt during the late cretaceous these are a metamorphic massifs b ophiolites c ophiolite related metamorphics and d granitoids the granitoids i e goksun afsin in kahramanmaras dogansehir in malatya and baskil in elazig intrude all the former units in a ne sw trending direction the granitoid in goksun afsin kahramanmaras region is mainly composed of granodioritic and granitic in composition the granodiorite contains a number of amphibole bearing mafic microgranular enclaves of different sizes whereas the granite is intruded by numerous aplitic dikes the granitoid rocks have typical calcalkaline geochemical features the ree and ocean ridge granite normalized multi element patterns and tectonomagmatic discrimination diagrams as well as biotite geochemistry suggest that the granitoids were formed in a volcanic arc setting the k ar geochronology of the granitoid rocks yielded ages ranging from 85 76 3 17 to 77 49 1 91 ma the field geochemical and geochronological data suggest the following late cretaceous tectonomagmatic scenario for southeast anatolia the ophiolites were formed in a suprasubduction zone tectonic setting whereas the ophiolite related metamorphic rocks formed either during the initiation of intraoceanic subduction or late thrusting 90 ma these units were then overthrust by the malatya keban platform during the progressive elimination of the southern neotethys thrusting of the malatya keban platform over the ophiolites and related metamorphic rocks was followed by the intrusion of the granitoids 88 85 ma along the tauride active continental margin in the southern neotethys

neogene tectonics and plate convergence in the eastern mediterranean new data from southern turkey data reported here demonstrate that the misis complex of southern turkey comprises a major olistostromic body formed prior to the early miocene and tectonically emplaced upon a structurally imbricated pile of deep and shallow marine sediments of early miocene to pliocene age magmatic rocks forming olistoliths in the misis complex have a back arc geochemical signature and variations in the facies paleoenvironments and paleotransport vectors within the associated sediments provide a record of miocene collisional events in southeast turkey the pseudo accretionary imbrication and structural style of the misis complex are attributed to continued collisional over thrusting but there is evidence within the imbricated stack of late sinistral strike slip faulting that relates to post miocene inception of motion along the east anatolian fault system the new data favor these geodynamic models proposed for the neogene evolution of the northeastern mediterranean that involve oblique convergence and associated strike slip adjustments

late cretaceous miocene sedimentary development of the arabian continental margin in se turkey adiyaman region implications for regional palaeogeography and the closure history of southern neotethys abstract the middle cretaceous late miocene sedimentary successions that are exposed on the arabian continental margin near adiyaman provide valuable insights into sedimentary tectonic and climatic processes that affected the southern neotethys and its continental margins deposition in the region began with aptian early campanian shelf carbonates followed by deepening during the mid campanian lithoclastic bioclastic turbidites accumulated along the downfaulted northern margin of the arabian platform during the campanian a flexurally controlled foredeep developed in advance of the emplacement of mesozoic allochthonous continental margin and oceanic rocks during the latest campanian early maastrichtian e g supra subduction zone kocali ophiolite alluvial detritus was shed from the emplaced allochthon in non marine to shallow marine deltaic settings during latest campanian early maastrichtian a marine transgression resulted in the establishment of a shallow marine shelf during the mid maastrichtian during the latest maastrichtian the platform submerged initiating deeper water hemipelagic sedimentation uplift took place during the palaeocene resulting in sediment instability slumping and formation of high density subaqueous gravity flows in response to regional faulting and tilting some areas in the north and the southwest emerged during the early middle eocene generating alluvial fans in a warm humid climate that favoured oxidation and reddening the likely control of the tectonic instability was far field compression related to the latest stages of subduction of the southern neotethys or the initial stages of collision of the arabian and tauride continents an oligocene hiatus is likely to reflect the formation of a collision related forebulge followed by flexural subsidence to form an early miocene foreland basin this was finally over ridden by the northerly active continental margin of the southern neotethys during early mid miocene regional suture tightening mid late miocene and related non marine coarse clastic sedimentation was followed by westward tectonic escape of the anatolian microplate towards the aegean region during plio quaternary time

linear and nonlinear diagnostic models of stationary eddies in the upper troposphere during northern summer abstract the upper tropospheric circulation during northern summer produced by a general circulation model gcm is studied using linear and nonlinear barotropic models and by analysing a streamfunction budget the model experiments and the budget calculations both show a simple sverdrup balance to he a useful first approximation for the largest scales during this season in this sverdrup balance the advection of planetary vorticity by the divergent component of the flow is found to be significant particularly in the southern hemisphere tropics nonlinear barotropic models improve the simulation of regional structures the correct position of the tibetan high is explained by sverdrup balance but its amplitude and structure are reasonably well simulated only with the nonlinear models with climatological forcing the time averaged solutions of the nonlinear model are insensitive to the strength of the damping included in the model the difference between the gcm s climatology and the gcm s flow in a par

record of cenozoic sedimentation from the amanos mountains southern turkey implications for the inception and evolution of the arabia eurasia continental collision abstract the sedimentary succession of the southern amanos mountains bordering the eastern margin of the karasu rift in south central turkey provides a record of environmental change from the eocene lutetian to the upper miocene tortonian that charts the final evolution of the northern margin of the arabian plate prior to and during continental collision eocene shallow marine carbonates hacidagi formation are interpreted as the youngest unit of the arabian passive margin succession deposited on a northwards facing carbonate ramp subsequent deformation and uplift took place during the oligocene represented by folding of the eocene and older strata this is interpreted to be the result of initial continental collision between arabia and eurasia unconformably overlying the eocene limestone are lower miocene conglomerates sandstones and palaeosols up to 150 m thick kici formation these were deposited in a range of marginal marine settings consisting of alluvial fan fan delta facies flood plain as well as basinal facies subsequently during the middle miocene local patch reefs developed in restricted areas kepez formation followed by upper miocene sediments gokdere formation composed of relatively deep water hemipelagic marl with clastic interbeds which represent a transgression during this period the upper miocene becomes sandier upwards this records the regression from the relatively deep water facies to coastal sediments water depth gradually became shallower until during pliocene time the area became continental in nature by the quaternary rifting had resulted in the development of the karasu rift with active alluvial fans along the margins and braided rivers depositing coarse conglomerates in the axial zone these conglomerates are interbedded with basaltic lava flows that resulted from the region extension across the area this research shows that initial continental collision occurred in this area after the lutetian 40 4 ma and before the aquitanian 23 03 ma supporting the hypothesis that the southern neotethys ocean closed during the late eocene to oligocene this was a time of climatic change including the onset of southern hemisphere glaciation in which the closure of the southern neotethys may have had played an important role

provenance and magmatic tectonic setting of campanian aged volcaniclastic sandstones of the kannaviou formation in western cyprus evidence for a south neotethyan continental margin volcanic arc abstract regionally developed late cretaceous subduction related magmatism in the eastern mediterranean records progressive closure of the southern neotethys in western cyprus the late cretaceous c 90 ma troodos ophiolite is depositionally overlain by volcaniclastic sandstones up to 750 m thick that are dominated by redeposited pyroclastic fallout interbedded with both non calcareous and calcareous radiolarian bearing mudstones the sands were mainly deposited by channelised mass flow processes and to a lesser extent by turbidity currents in a deep water forearc basin the succession was folded and locally thrust deformed related to latest cretaceous emplacement of adjacent mesozoic continental margin and oceanic units mamonia complex sims u pb analysis of euhedral to subhedral magmatic zircon crystals yielded a weighted mean 206pb 238u age of 80 1 1 1 ma campanian sandstone petrography including compositional framework q12f21l67 suggests sediment supply from a volcanic arc subordinate continentally derived detritus suggests a continental margin arc setting for the mafic to felsic fallout ash sims analysis of little altered volcanic glass indicates high th nb and th la ratios that suggest the involvement of continental crust and or subducted terrigenous sediments in magma genesis whole rock chondrite normalised ree patterns have comparable trends to modern and ancient forearc basin volcaniclastic sands and sandstones e g northwest pacific region trace element chemistry although scattered towards the continental island arc fields on some geochemical diagrams e g th sc zr mainly suggests an oceanic island arc source for the kannaviou formation sandstones with variable enrichments in v cr ni sc depletion in nb ta and relatively low trace element ratios e g la co th co la sc th sc an explanation for this apparent discrepancy is that the volcaniclastic sandstones were derived from a relatively primitive arc constructed on previously depleted rifted thinned neotethyan continental crust the inferred continental margin arc developed during early stage northward subduction of the southern neotethys beneath a tauride microcontinent to the north large volumes of volcanic ash were derived from continental margin arc volcanism probably in the vicinity of the kyrenia range in northern cyprus

tomographic evidence of slab detachment beneath eastern turkey and the caucasus summary teleseismic phase readings from the eastern turkey seismic experiment etse have been inverted using teleseismic tomography in order to create a 3 d image of the underlying mantle beneath eastern turkey the aim was to investigate the existence of an upper mantle negative velocity anomaly that is used to explain the uplift of eastern anatolian plateau and the potential pieces of detached oceanic slabs related to neo tethyan subduction suggested by previous studies using teleseismic waveforms from the 29 stations of the eastern turkey seismic experiment 2926 direct p phases from 146 events were picked by using adaptive stacking techniques in order to increase the station coverage and resolve the surrounding area the phase readings from the international seismological center isc bulletin have also been added the data set consists of 9571 p and pkp phase readings of 79 stations from 503 teleseismic events this study develops the first highresolution 3 d upper mantle p wave tomographic model for this region the tomographic results show the existence of an upper mantle negative velocity anomaly to a depth of 200 km beneath the eastern anatolian accreationary complex eaac as commonly observed in the previous studies that suggest a shallow partially molten asthenosphere the slab like high velocity anomalies beneath the eaac pontides and caucasus are interpreted as the detached southern and northern neo tethys slabs

late cretaceous cenozoic subduction collision history of the southern neotethys new evidence from the caglayancerit area se turkey evidence of the subduction collision history of the s neotethys is well exposed in the frontal part of the se anatolian thrust belt and the adjacent arabian continental margin the foreland succession in the study area begins with eocene shelf carbonates ranging from shallow marine to deeper marine without sedimentary input from the tauride continent to the north after a regional hiatus oligocene sedimentation resumed during the early miocene with terrigenous gravity flow deposition in the north lice formation and shallow marine carbonates further south clastic detritus was derived from the tauride continent and oceanic accretionary material the base of the overriding tauride allochthon comprises ophiolite derived debris flows ophiolite related melange and dismembered ophiolitic rocks above this the regional scale bulgurkaya sedimentary melange an olistostrome includes blocks and dismembered thrust sheets of metamorphic rocks limestone and sandstone which include late cretaceous and eocene foraminifera the matrix is mainly strongly deformed eocene oligocene mudrocks hemipelagic marl and sandstone turbidites the thrust stack is topped by a regionally extensive thrust sheet malatya metamorphic unit which includes greenschist facies marble calcschist schist and phyllite representing tauride continental crust beginning during the late mesozoic the s neotethys subducted northwards beneath a backstop represented by the tauride microcontinent malatya metamorphic unit ophiolites formed within the s neotethys and accreted to the tauride active margin large scale sedimentary melange developed along the tauride active margin during eocene oligocene on the arabian margin a sedimentary hiatus and tilting oligocene is interpreted to record initial continental collision the early miocene terrigenous gravity flows represent a collision related flexural foreland basin southward overthrusting of the tauride allochthon took place during early middle miocene associated regional uplift triggered large scale alluvial deposition the foreland folded and faulted in response to suture zone tightening late miocene left lateral strike slip characterised the plio pleistocene

southeast anatolian orogenic belt revisited geology and evolution the southeast anatolian orogenic belt consists of the arabian platform a zone of imbrication and a nappe zone the arabian platform is represented by a thick marine succession the zone of imbric

u pb and 40ar 39ar geochronology and isotopic constraints on the genesis of copper gold bearing iron oxide deposits in the hasancelebi district eastern turkey the hasancelebi deposit in eastern turkey with proven reserves of 95 million metric tons is a copper gold bearing iron oxide deposit it is chiefly hosted by rocks that underwent widespread sodic calcic and potassic styles of alteration in the hasancelebi district pervasive na ca and k fe alteration types are overprinted by sericitization and by late alteration that occur in multiple overprinting systems the age of hydrothermal alteration and mineralization ca between 74 68 ma overlaps with the age of alkaline magmatism in the hasancelebi district crystallization and cooling of alkaline magmatism is associated with hydrothermal features that spanned the duration of the district s igneous history the 40ar 39ar and u pb geochronology of magmatism indicate that the hydrothermal system was synchronous with diabase and syenite and or microsyenite porphyry intrusions and consisted of several discrete phases of na ca and k fe alteration the oldest alteration phase 1 formed at ca 74 4 to 74 3 ma it is spatially and temporally associated with the emplacement of diabase dikes and contains scapolite and phlogopite the next younger alteration phase 2 formed at about 71 3 ma and is spatially and temporally associated with syenite porphyry and microsyenite porphyry intrusions it consists of scapolite garnet pyroxene and actinolite that are superimposed on the first alteration phase the next alteration assemblage phase 3 formed at about 68 6 ma and consists of phlogopite 2 and magnetite mineralization still later alteration phase 4 overprints phases 1 2 and 3 and consists of sericite quartz chalcopyrite hematite calcite fluorite and barite oxygen 18o and hydrogen d isotope analyses were carried out on phlogopite sericite barite calcite fluorite and quartz representing the mineral assemblage formed during phases 1 and 4 of the hydrothermal alteration the calculated 18o h2o and d h2o composition of the fluids that formed preore k fe alteration and postore alteration of phase 4 range between 15 1 to 8 5 and 124 to 85 6 per mil respectively and partially overlap the range for traditional magmatic waters oxygen and h isotope compositions from alteration minerals highlight two major points na ca and k fe alteration assemblages are likely derived from high temperature primary magmatic fluids and late sericitization is likely derived from fluids exsolved from cooling alkaline plutons during hydrothermal fracturing and consequent degassing at moderate temperatures the initial ndi values of the alteration zones range from 2 02 to 2 08 close to the calculated nd value of associated syenite porphyry at the time of alteration nd 68 64ma 1 9 nd sr isotope compositions combined with 40ar 39ar and u pb geochronology of the associated alteration suggest that the fluids were sourced from coeval diabase dikes and syenite porphyry and or microsyenite porphyry intrusions the rare earth element characteristics 40ar 39ar and u pb geochronology of alteration and fresh magmatic rocks 18o d nd and sr isotope systematics together suggest that the fluids responsible for the high to moderate temperature assemblages are largely derived from the coeval alkaline igneous rocks diabase and microsyenite porphyry dikes that intrudes the sedimentary volcanosedimentary basin

comprehensive comparison among the campbell bozorgnia nga west2 gmpe and three gmpes from europe and the middle east campbell and bozorgnia 2006 compared their newly developed next generation attenuation west1 project nga west1 ground motion prediction equation gmpe with a contemporary gmpe developed for the active crustal region of europe and the middle east based on that comparison they proposed that their gmpe could be used to estimate ground motions in these regions later studies by a number of investigators confirmed this proposal for several of the nga gmpes using available pan european gmpes and european strong motion data in this study i performed a detailed comparison of the nga west2 gmpe of campbell and bozorgnia 2014 with three newly developed gmpes for the pan european region the comparisons were performed in terms of median predictions standard deviations and residual analyses with respect to the nga west2 database used to develop the nga west2 gmpe these comparisons indicate that the scaling characteristics of all four gmpes are generally comparable in terms of attenuation and linear site response but differ in terms of scaling with magnitude source depth style of faulting and nonlinear site effects these differences are not scientifically significant and are not found to be statistically significant for the pan european events of similar magnitude in the nga west2 database as a result i propose that the gmpe of campbell and bozorgnia 2014 can be used to estimate ground motions from moderate to large magnitude earthquakes in pan europe as a means of more reliably extending these estimates to large magnitudes and short distances of greater engineering interest and to include ground motion scaling features that are not currently included in pan european gmpes

the post eocene evolution of the doruneh fault region central iran the intraplate response to the reorganization of the arabia eurasia collision zone

paleomagnetic results along the bitlis zagros suture zone in se anatolia turkey implications for the activation of the dead sea fault zone abstract the tectonic evolution of se anatolia is associated with the collision between the taurides and the arabian platform in the early cenozoic after the final closure of the southern branch of the neotethys ocean during late cretaceous to early eocene times the ongoing deformation was characterized by northward movement of arabia followed by westward extrusion of anatolia having been displaced along the northern and eastern anatolian transform faults the neotectonic deformation history between the anatolian plate and the arabian platform since the closure of the southern neotethyan oceanic basin from late cretaceous to present has not been studied in detail paleomagnetically therefore we carried out a paleomagnetic study of mesozoic and cenozoic rocks at 34 localities along the bitlis zagros suture zone in se anatolia located in the boundary region between the taurides and the arabian platform and delimited by the dead sea fault paleomagnetic results from the area show clockwise rotations of 35 6 14 1 and 26 7 8 0 with respect to the african plate from upper jurassic lower cretaceous and upper cretaceous limestones respectively the paleomagnetic results indicate also an earlier deformation opening due to the dead sea fault zone dsfz farther north on the tauride block counterclockwise rotation of 34 5 12 5 is recorded by upper cretaceous limestones in the se of the study area on the northern margin of arabia however smaller counterclockwise rotations of 12 3 8 3 and 2 5 10 0 in late cretaceous and 12 7 13 6 in middle eocene rocks show relative tectonic stability middle miocene rocks close to the suture zone show counterclockwise rotation by about 39 4 10 9 while farther away from the suture zone counterclockwise rotations of 21 9 9 9 and 7 5 5 8 are observed paleolatitudinal motion from south to north from the late jurassic to the present is in concordance with the apparent polar wander path of eurasia and africa

the petrogenesis of leucogranitic dykes intruding the northern semail ophiolite united arab emirates field relationships geochemistry and sr nd isotope systematics the khawr fakkan block of the semail ophiolite united arab emirates exhibits a suite of 10 100 m scale metaluminous to peraluminous granitic intrusions ranging from cordierite andalusite biotite monzogranites to garnet tourmaline leucogranites which intrude mantle sequence harzburgites and lower crustal sequence cumulate gabbros structural constraints suggest that the subduction of continental sedimentary material beneath the hot proto ophiolite in an intra oceanic arc environment led to granulite facies metamorphism at the subduction front and the generation of granitic melts which were emplaced up to the level of the ophiolite moho compositions indicate the analysed granitoids were largely minimum melts that crystallised at variable a h2o and pressures of 3 to 5 kbar the lile sr rb and ba covariation modelling suggests that the granitoids formed largely by the dehydration melting of muscovite rich metasediments initial 87sr 86sr ratios of analysed dykes vary between 0 710 and 0 706 at initial nd values of between 6 3 and 0 5 cogenetic units of a composite sill from ra s dadnah yield a sm nd isochron age of 98 8 9 5 ma mswd 1 18 geochemical and isotopic characteristics of the analysed granitic intrusions indicate that the subducted continental material was derived from oceanic trench fill haybi complex sediments preserved as greenschist asimah area to granulite facies bani hamid area ophiolitic metamorphic sole terranes the sr nd isotope systematics suggest that hybrid granitic melts were derived from pre magmatic mixing of two contrasting subduction zone sources

the role of the early tertiary ulukisla basin southern turkey in suturing of the mesozoic tethys ocean the maastrichtian late eocene ulukisla basin is representative of the tectonic and sedimentary evolution of prominent early tertiary basins in central anatolia including the tuzgolu and arkisla basins the ulukisla basin overlies an ophiolitic melange of late cretaceous age between the bolkar carbonate platform to the south and the nigde kirsehir metamorphic massif to the north the basin stratigraphy records successive phases of transgression subsidence volcanism evaporite deposition deformation and uplift subsidence curves are consistent with an extensional or transtensional basin origin terminated by uplift the ulukisla basin includes a thick succession c 2 km of upper paleocene lower eocene basaltic to andesitic submarine pillow lavas lava flows volcaniclastic rocks and intercalated limestones whole rock xrf chemical analysis indicates a within plate origin with a marked subduction influence believed to be inherited rather than contemporaneous the ulukisla basin formed after late cretaceous ophiolite and melange emplacement and ended with late eocene emergence deformation and onset of oligo miocene non marine deposition we propose that late cretaceous ophiolite and melange emplacement reflect initial ocean basin closure this was followed by a long period c 30 ma of microcontinental adjustment including possible strike slip palaeorotation and suture tightening during which the early tertiary ulukisla basin developed possible driving forces were regional slab pull of a relict subduction zone or oblique diachronous convergence suture tightening was complete by late eocene time marked by collisional deformation and regional uplift

new evidence and model on the evolution of the southeast anatolian orogen this paper describes the orogenic evolution of the southeast anatolian orogenic belt based mostly on new geologic data collected from its constituent tectonic units in the course of new mapping programs of the past decade the southeast anatolian orogenic segment of the alpides may be divided into three approximately east west trending zones from south to north they are the arabian platform followed by a zone of imbrication and then a zone of nappes the arabian platform includes a mostly marine sedimentary succession deposited from early cambrian to middle miocene time the zone of imbrication is a narrow belt sandwiched between the arabian platform and the zone of nappes it consists of imbricated thrust slices emplaced onto a late cretaceous to early miocene sequence the zone of nappes is the highest tectonic unit consisting of two stacks of nappes simply designated the lower and upper nappes the lower nappe is represented by the slices of a polyphase metamorpbic ophiolitic assemblage and the maden group the upper nappe rests on the lower nappe and is represented by the bitlis and poturge metamorphic massifs southeastern anatolia underwent two major episodes of alpide deformation the first occurred during the late cretaceous period when ophiolite was emplaced on the arabian platform this event was not the consequence of a continental collision the ophiolite obduction onto the arabian platform was followed by a regionwide extension and a new marine transgression over the platform immediately after the ophiolite obduction the second episode of deformation occurred during middle eocene miocene time in two distinct stages as a result of the progressive elimination and complete closure of the ocean s which led to the collision between the zone of nappes located to the north being a part of eurasia and the arabian plate the maden marginal basin formed north of the subduction zone that eliminated the ocean between eurasia and arabia along the southern margin of the taurus belt and abutted the arabian plate much later during the final collision the second episode of deformation formed the present orogenic segment leading to the amalgamation of different tectonic units these amalgamated nappes collided with the arabian plate and welded onto it at the latest stage of the orogenic evolution during the miocene epoch

multiple exhumation phases in the central pontides n turkey new temporal constraints on major geodynamic changes associated with the closure of the neo tethys ocean

the golbaoi basin southeastern turkey a complex discontinuity in a major strike slip fault zone we show that the 33 km long golbaoi basin on the east anatolian fault zone marks the triple junction between the african arabian and turkish plates the main strand of the turkish arabian plate boundary the goksu fault enters this basin from the ene before splaying to form faults which develop farther southwest into the turkish african and african arabian boundaries the golba i turko u fault the turkish african boundary is shown to have slipped 16 km the prevously unrecognised kirkpmar fault the african arabian boundary has slipped 17 km we propose that this fault geometry developed at c 3 ma following earlier slip starting at c 5 ma on other strike slip faults nearby which marked the start of westward motion of the turkish plate

the temporal evolution of the active margin along the southeast anatolian orogenic belt se turkey evidence from u pb ar ar and fission track chronology abstract the southeast anatolian orogenic belt saob resulted from the north dipping subduction of the southern neotethyan oceanic lithosphere in late mesozoic and early cenozoic however the timing and the rate of the continental collision are still under debate here we present new u pb ar ar and fission track ages from the i type calc alkaline granitoids esence dogansehir and baskil cutting the goksun ispendere and komurhan ophiolites and also the malatya keban metamorphics representing the tauride active continental margin along the saob in this study high to low temperature thermochronological methods applied to the granitoids are used to understand the temporal and geodynamic evolution of the tauride active continental margin and continental collision between tauride and arabian platforms in the frame of the neotethyan convergence during cretaceous and miocene the u pb zircon ages range from 83 to 88 ma for the baskil and from 81 to 83 ma for the esence granitoids the 39 ar 40 ar ages indicate that these late cretaceous granitoids cooled below 300 c in 6 10 ma the formation ages and the timing of the gradual cooling of the late cretaceous granitoids are similar to metamorphism age and the timing of the exhumation of the hp lt bitlis metamorphics during this stage the combined field geochemistry and geo thermochronological data suggest that the first continental collision event occurred between bitlis puturge micro continents to the south and tauride platform to the north in an oblique subduction zone between 84 and 74 ma the granitoids continued uplifting during early middle eocene together with the exhumation of hp uht berit metaophiolite in an extensional regime related to the opening of the maden back arc basin this period also let the intrusion of the dogansehir arc magmatism intruding the puturge and malatya keban metamorphics berit metaophiolite and maden complex the eocene dogansehir granitoid has similar u pb and 39 ar 40 ar ages suggesting a fast cooling the apatite fission track aft ages for all granitoid bodies suggest that they were mainly cooled or uplifted in two episodes where the first one is in the eocene in an extensional setting the aft data marked the final continental collision between the taurides and the arabian platform first in oligocene and the break off of the subducted slab and the delamination process caused fast uplift of the eastern anatolia during middle to late miocene

ophiolitic and metamorphic assemblages of southeast anatolia and their significance in the geological evolution of the orogenic belt the southeast anatolian orogen may be divided into three roughly east west trending structural zones formed as a result of continental collision between the taurus platform and the arabian continent along the orogenic belt metamorphic and ophiolitic rocks occur widely the ophiolites represent remnants of the ocean or oceans which were totally consumed between these converging continental blocks during late cretaceous to miocene period metamorphic rocks formed from the oceanic as well as the continental rocks which were incorporated into a nappe stack during the consumption of the oceanic lithosphere and the progressive southward advance of the nappes toward the arabian continent the metamorphic units together with the ophiolite associations provide stratigraphic and petrologic evidence indicating time place and environment of formation of these units the metamorphic units also provide evidence of nappe transportation stages which are complementary to the data derived from the sedimentary successions in the evaluation of the orogenic evolution of southeast anatolian orogen

evidence of eocene high temperature high pressure metamorphism of ophiolitic rocks and granitoid intrusion related to neotethyan subduction processes dogansehir area se anatolia

the uplift history of the arabian plateau as inferred from geomorphologic analysis of its northwestern edge abstract the arabian plateau ap is an oligocene sub horizontal regional planation surface extending throughout the western half of the arabian peninsula its present elevation of about 1 km required a prominent uplift since the late eocene in order to reconstruct the uplift history we documented abundant abrasive and fluvial terraces that were left along and across the raised judea mountains jm which comprised the nw edge of the ap using the ages of those terraces and the differences in height between them we found that the jm was uplifted in three major phases a few hundred meters during the late eocene early oligocene 500 m during the early miocene early middle miocene and 350 m during the late pliocene the two earliest uplift phases predate the formation of the dead sea transform dst which today separates the jm from the ap meaning that these two phases affected the continuous rigid lithosphere extending southeastwards to the ap interiors moreover restoration of the paleogeography predating the lateral offset along the dst eliminates the main height differences across it and suggests that the dst does not play a major role in the vertical position of its bordering plates but rather forms a relatively narrow deformation strip within the ap those two early phases of uplift can be corroborated by previous thermochronology studies which exhibit similar ages around the red sea but may reflect the uplift age of the entire region the present sub horizontal morphology of the ap is in contrast to the presumed original northeastward drainage and may suggest a subsequent long wave moderate tilting to the sw three possible mechanisms were suggested for the uplift of the ap a long wavelength flexure of the arabian plate during early stages of the uplift and lithospheric thinning or dynamic topography during later stages of the uplift

late eocene neogene sedimentary geology of the girne kyrenia range northern cyprus a case history of sedimentation related to progressive and diachronous continental collision abstract sedimentary geology can shed light on the processes of continental collision the easternmost mediterranean provides an exceptional opportunity to study sediments deposited during progressive and diachronous continental collision with implications for comparable settings elsewhere here we focus on sediment sources pathways and deposition of mostly deep sea clastic sediments exposed in northern cyprus the sedimentary basin forms part of the northern continental margin of the southern neotethys ocean and is represented by a ca 200 km long e w trending arcuate lineament encompassing northern cyprus and its submarine link with turkey the upper eocene upper miocene basin was divided into northerly and southerly sub basins during mid to late miocene time by an e w trending inferred syn depositional fault lineament the sequence begins with non marine to shallow marine basal conglomerates late eocene that abruptly fine upwards into siliciclastic turbidites oligocene followed by biogenic calciturbidites and marls aquitanian langhian during mid late miocene the northerly sub basin was characterised by thin to medium bedded calciturbidites and marls serravallian overlain by thick bedded medium grained lithic sandstones tortonian in contrast the southern sub basin is dominated by siliciclastic turbidites with abundant sole structures burdigalian tortonian palaeocurrent evidence indicates dominantly westward sediment transport especially during the late miocene the serravallian tortonian sandstones of the northern sub basin are relatively rich in carbonates while the southern sub basin contains more siliciclastic and ophiolite derived detritus indicating differences in sediment supply in general the upper eocene basal conglomerates were mainly derived from the north from within the girne kyrenia range and its inferred northward extension in response to rapid subsidence reflecting possible southward subduction zone retreat clastic sediment sources to the north then submerged while clastic sediment was instead mainly supplied from the south neotethyan suture zone to the east and northeast in southern turkey reflecting diachronous collision deep water deposition persisted in the easternmost mediterranean basin further west until this was terminated in northern cyprus by thrusting folding during latest miocene earliest pliocene quaternary collision related uplift ensued similar sedimentary development is to be expected in collisional settings elsewhere e g tethyan closure in the himalayas iapetus closure in the appalachians

provenance of the northern part of the kahramanmaras peripheral foreland basin miocene s turkey abstract the miocene kahramanmaras peripheral foreland basin kpfb resemble to classic foreland basin model with small differences in the classic model both the accretionary wedge and foredeep extend lengthways parallel to the plate margin in addition accretionary wedge includes wedge top basin or piggy back basin that extends parallel to foredeep however the accretionary wedge of the kpfb contains small half graben type basins that obliquely intersect the plate margin between the arabian plate and the anatolide taurides platform due to the irregular shape of the plate boundary tectonic lineaments controlled the shape and orientation of these basins and larger main depocentre of the kfpb which were predominantly filled with deep sea sediments this paper focuses on the provenance of features of the kfpb predominantly was fed from the northern basin margin while also aiming to resolve the complex basin evolution that occurred during the miocene clasts of palaeozoic and mesozoic limestone and ophiolites are common components of the confined deep water clastic systems which evolved as elongated trenches in the north western sector of the kpfb during the early middle miocene during the middle miocene continuous thrusting of the northern basin margin to south caused depocentre migration to south east through the basin interior at that time the north east and central depocentres of the kpfb were filled primarily by clasts of ophiolite and metamorphic units the tectonic control on basin fill architecture can be observed anywhere in the kfpb the principal tectonic features controlled the geometry and orientation of the canyon the channel geometry of the deep water slope on the northern basin margin the frequency and distribution of slump slide debris flows and the overall pattern of sedimentation cycles in the stratigraphy of the slope and the central basin floor some basin sectors have continuously reactivated and as a result different sediment entry points with substantial local accumulation of sediment and deformation have evolved on the slope and basin floor three scales of provenance were used to investigate the source rock a field based observation and analysis of conglomerate clasts b modal analysis of sandstone facies and c geochemical analysis all of which were in agreement

the beysehir hoyran hadim nappes genesis and emplacement of mesozoic marginal and oceanic units of the northern neotethys in southern turkey the beysehir hoyran hadim nappes crop out over 700 km from nw to se above a regionally autochthonous tauride carbonate platform the beysehir hoyran nappes begin with a thrust sheet c 400 m of mainly redeposited carbonates quartzose sandstones and mudstones of mid late triassic age interpreted as a proximal slope base of slope succession above is a thrust sheet c 1 km of middle upper triassic intermediate acidic extrusive rocks volcaniclastic rocks and minor pelagic carbonates interpreted as a continental rift thin

tectonic setting origin and obduction of the oman ophiolite the semail ophiolite in the oman mountains is the world9s largest and best preserved thrust sheet of oceanic crust and upper mantle 10 000 km 2 550 km long 150 km wide it was emplaced onto the arabian continental margin during late cretaceous time the ophiolite originated 96 94 ma at a spreading center above a northeast dipping subduction zone associated with initiation of immature island arc tholeiitic lavas lasail arc at the highest levels of the ophiolite simultaneous underthrusting of triassic and jurassic mid oceanic ridge basalt and alkalic volcanic rocks beneath 12 km of upper mantle depleted harzburgites produced garnet clinopyroxene amphibolites formed at temperatures of 850 c dated as 95 93 ma subduction cannot have been initiated at a mid oceanic ridge otherwise the protolith of the amphibolites in the metamorphic sole would be the same age and composition as the ophiolite volcanic rocks above in the northern part of the oman mountains in the bani hamid area united arab emirates 870 m of granulite facies rocks enstatite spinel diopside quartzites garnet diopside wollastonite calc silicate marbles clinopyroxene bearing amphibolites were formed at temperatures similar to those of the garnet diopside amphibolites of the oman sole 800 850 c but at slightly higher pressures as much as 9 kbar they are interpreted as deeper level metamorphosed continental margin sedimentary rocks exhumed by out of sequence thrusting placing granulites over mantle sequence harzburgites during the later stages of obduction subduction of the arabian continental crust beneath the obducting semail ophiolite to 78 90 km depth has been proven by thermobarometry of the as sifah eclogites to 20 23 kbar in the eastern sector in the united arab emirates the subducted continental crust began to partially melt producing unusual biotite muscovite garnet tourmaline cordierite andalusite bearing granites that intrude the uppermost mantle sequence harzburgites and lowermost crustal sequence cumulate gabbros of the ophiolite we suggest that the entire leading northeast edge of the arabian plate was subducted beneath the ophiolite during the final stages of obduction leading to eclogitization of the crustal rocks higher temperatures and pressures in the united arab emirates sector possibly due to a thicker or double thickness ophiolite section led to blueschist amphibolite and granulite facies conditions in the metamorphic sole and crustal melting in the subophiolite basement produced leucocratic granites that intruded up as dikes through the obducted ophiolite a model for ophiolite obduction is presented which accounts for all the structural and metamorphic conditions reported from the oman mountains

high pressure metasediments in central turkey constraints on the neotethyan closure history 1 the distribution of oceanic domains and continental blocks in central anatolia remains a challenge in understanding the alpine geodynamic evolution of the tethys realm the consumption of a neotethys oceanic branch at the mesozoic cenozoic boundary welded the central anatolian crystalline complex in central turkey and the anatolide tauride block in western turkey with the northerly eurasian margin whether those two regions constituted a single or two distinct continental masses is still matter of debate high pressure metamorphism has been locally evidenced in the afyon zone which was however defined as a greenschist facies metamorphic zone of the anatolide tauride block since the afyon zone composes a metamorphic equivalent of a continental margin exposed far south of the izmir ankara suture zone this encouraged us to reevaluate its metamorphic evolution in order to better understand the relation between western and central turkey our investigations reveal that the high pressure minerals fe mg carpholite and glaucophane are present in the entire afyon zone which we reconsider as a blueschist facies zone we additionally present a tectonic reconstruction stripping off the postcollisional tectonics it reveals that today s bending of the high pressure belt is consistent with an eocene collision of the anatolide tauride block around the southern edge of the central anatolian crystalline complex we argue that the central anatolian crystalline complex and the anatolide tauride block were two distinct continental masses separated by a neotethyan oceanic stripe the closure of which engendered subduction related metamorphism in the latter and arc volcanism and high grade metamorphism in the former by late cretaceous to early cenozoic

accelerated subsidence and sedimentation in the levant basin during the late tertiary and concurrent uplift of the arabian platform tectonic versus counteracting sedimentary loading effects 1 since the middle eocene the northwest arabian platform has been emerging from the water and rising above sea level whereas the adjacent levant basin has been subsiding and accumulating a thick sedimentary section this study investigates these opposing vertical motions and the relative roles of tectonic driven versus isostatic adjustment forces involved such a distinction is strongly dependent on a reliable estimation of the paleobathymetry which in pelagic environments may vary substantially we use two different methods to estimate the paleo water depth in the deep levant basin in the tertiary time isostatic balancing calculations with the adjacent inland region are employed to estimate the paleo water depth in the deep levant basin in the middle eocene just before the commencement of the late tertiary tectonic phase for later periods we use morpho structural elements such as abrasion surfaces and incised canyons to build laterally changing topo bathymetry profiles our results indicate that in the mid eocene water depth in the deep levant basin was 2 3 5 km which gradually decreased to 1 5 km today based on these results our analysis shows that the enhanced subsidence of the levant basin reflects an isostatic response to sedimentary filling of a pre existing deep water basin with no involvement of a downward tectonic force on the contrary we suggest that the regional tectonic force was upward counteracting a sedimentary loading effect further regional implication of this understanding is that the cause for uplifting and exposure of the nw arabian platform in the late tertiary extended far westward beyond the inland region

new paleomagnetic results from upper cretaceous arc type rocks from the northern and southern branches of the neotethys ocean in anatolia a paleomagnetic study of cretaceous arc type rocks in the central eastern pontides and in the southeastern taurides investigates the tectonic and paleolatitudinal evolution of three volcanic belts in anatolia namely the northern and southern volcanic belts in the pontides and the se taurides volcanic belt the paleomagnetic data indicate that magnetizations were acquired prior to folding at most sampling localities sites except for those in the erzincan area in the eastern pontides the southern volcanic belt was magnetized at a paleolatitude between 23 8 3 8 4 2 n and 20 2 1 2 1 3 n hisarli j geodyn 52 114 128 2011 reported a more northerly paleolatitude 26 6 4 6 5 1 n for the northern volcanic belt the comparison of the new paleomagnetic results with previous ones in anatolia allows to conclude that the southern volcanic belt in the central eastern pontides was emplaced after the northern volcanic belt as a result of slab roll back of the northern neotethys ocean in the late cretaceous in the southeast taurides upper cretaceous arc related sandstones were at a paleolatitude of 16 8 3 8 4 2 the late cretaceous paleomagnetic rotations in the central pontides exhibit a counterclockwise rotation of r pm delta r 37 1 circ pm 5 8 circ group 1 cankiri yaylacayi formation while maastrichtian arc type rocks in the yozgat area group 2 show clockwise rotations r r 33 7 8 4 and r r 29 3 6 0 in the se taurides counterclockwise and clockwise rotations of r pm delta r 48 6 text circ text pm 5 2 text circ text and r pm delta r 34 1 text circ text pm 15 1 text circ text are obtained group 4 elazig magmatic complex the late cretaceous paleomagnetic rotations in the pontides follow a general trend in concordance with the shape of the suture zone after the collision between the pontides and the kirsehir block the affect of the westwards excursion of the anatolian plate and the associated fault bounded block rotations in miocene are observed in the east of the study area and the se taurides

andean type active margin formation in the eastern taurides geochemical and geochronogical evidence from the baskil granitoid elazig se turkey abstract the southeast anatolian orogen resulted from collision of the afro arabian and the eurasian plates following the cretaceous to miocene closure of the southern neotethyan oceanic basin in this orogenic belt there are number of tectonomagmatic stratigraphic units in the kahramanmaras malatya elazig region that are important to understand the geological evolution of southeast anatolia during the late cretaceous these are a metamorphic massifs i e malatya keban platform b ophiolites i e goksun ispendere komurhan c ophiolite related metamorphics i e berit metaophiolite and d granitoids i e goksun dogansehir and baskil the baskil granitoid crops out to the northwest of elazig and is a large magmatic body 170 km2 that intruded all of the above mentioned units during late cretaceous time the baskil granitoid comprises both mafic and felsic plutonic sub plutonic rock associations the felsic plutonic phase includes granite granodiorite tonalite and quartz monzonite whereas the felsic sub plutonic phase is characterized by aplite granophyre granite porphyry and granodiorite porphyry the granite and granodiorite contain mafic microgranular enclaves mme the mafic plutonic phase comprises gabbro diorite quartz diorite whereas the mafic sub plutonic phase is represented by diabase microdiorite quartz microdiorite diorite porphyry quartz diorite porphyry and dykes of orbicular gabbro dyke geochemically the baskil granitoid rocks have i type metaluminous peraluminous calc alkaline characteristics the ree and ocean ridge granite normalized multi element patterns and tectonomagmatic discrimination diagrams together with biotite geochemistry suggest that the granitoids were formed in a volcanic arc setting the40ar 39ar geochronology of the granitoid rocks yielded biotite ages of 81 9 0 7 ma and 81 5 0 8 ma 95 confidence level coexisting hornblende and hornblende from additional samples yielded ages ranging from 84 0 0 7 ma to 81 5 1 1 ma the ophiolites are believed to have formed in a suprasubduction zone tectonic setting whereas the ophiolite related metamorphic rocks formed either during the initiation of intraoceanic subduction or later stage thrusting 90 ma these units were then thrust beneath the malatya keban platform during the progressive closure of the southern neotethys this was followed by intrusion of the granitoids 85 82 ma along the tauride active continental margin of the southern neotethys

structure and petrology of tauride ophiolites and mafic dike intrusions turkey implications for the neotethyan ocean cretaceous neotethyan ophiolites occur in four east west trending subparallel zones within the tauride tectonic belt in southern turkey the ophiolites of the inner intermediate and outer zones tectonically overlie the mesozoic platform carbonates of the tauride belt and are commonly underlain by a cenomanian ophiolitic melange these ophiolites consist mainly of tectonized mantle rocks mafic ultramafic cumulates and gabbros and commonly lack sheeted dike complexes and extrusive rocks of a complete ophiolite sequence metamorphic soles that are several hundred meters thick occur as thrust faulted slices beneath these ophiolites and show well developed metamorphic field gradients ophiolitic units and the metamorphic soles are intruded by mafic dike swarms that are truncated at the contact with the underlying melange unit dike rocks are made of subalkalic basalt to andesite typical of evolved island arc tholeiites they display large compositional variations with sio 2 content between 50 and 60 wt and mgo between 8 and 4 wt and contain higher ti augite phenocrysts and significantly less calcic plagioclase than their host cumulates the majority of the analyzed dike rocks show a slight depletion in light rare earth elements ree with low la smn ratios and are depleted in both high field strength hfs and heavy rees while enriched in large ion lithophile elements lile relative to normal mid ocean ridge basalt morb these characteristics suggest a mantle source that underwent previous melt extractions and subsequent metasomatism by lile and light ree enriched fluids geochemical modeling of trace elements shows that melting occurred at relatively low pressures under hydrous conditions and that it may have required the existence of an asthenospheric window in which the dike magmas developed through tapping and mixing of melts generated within a rising melting column starting slightly within the garnet stability field or in a transitional zone between the garnet and spinel stability fields at about 60 km depth this asthenospheric window was probably created during subduction of a neotethyan ridge system magmas ascending from the melt column within this window generated dikes that crosscut the metamorphic soles and were injected into the overlying mantle wedge and oceanic lithosphere the new 40 ar 39 ar hornblende dates of 92 90 ma and 90 91 ma from the metamorphic soles and dike swarms respectively show that evolution of these two geologic units was closely related in time and space and that they formed at the same intraoceanic subduction zone within the inner tauride seaway these data suggest that the tauride ophiolites within the three zones to the north originated from the same root zone situated north of the tauride carbonate platform and that they constitute remnants of a single ophiolitic nappe sheet derived from the inner tauride seaway within the neotethyan ocean

kinematic evolution of the tethys belt from the atlantic ocean to the pamirs since the triassic abstract we present an updated series of kinematic reconstructions of the major plates around the tethys from the atlantic ocean to the pamirs between the early jurassic and the present this set is used elsewhere as a basis for paleogeographic maps of the entire region the problems related to the positions of the continents in the lower triassic are also discussed no direct analyses of magnetic anomalies and fracture zones in the atlantic have been made rather all available poles and rotations have been tested in order to eliminate or minimize possible kinematic errors the reconstructions are shown for nine key geological periods which correspond to well recognized magnetic anomalies except for the jurassic cretaceous boundary and the cretaceous tertiary boundary which correspond to interpolated positions paleolatitudes have been drawn using the study of westphal et al 1986 an attempt has been made to take into account the displacements caused by formation of the continental margins and basins by stretching the resulting relative vector of motions along the northern boundary of the tethys shows a significant change 80 m y ago left lateral motion with compression dominates before whereas right lateral motion with compression dominates after to the east rates of motion vary by a factor of three with time and four maxima can be clearly related to tectonic events in the late jurassic late cretaceous eocene and post middle miocene to the west north of apulia on the contrary the motion rate has not changed significantly since the early cretaceous and is close to 1 cm yr as an average these rather complex adjustments in rates and directions of relative motion are produced in great part through a complex migration of the africa eurasia pole of rotation and seem to be mostly governed by the tectonics of the tethys plate boundary

evidence of clastic evaporites in the canyons of the levant basin israel implications for the messinian salinity crisis abstract the recognition of large clastic sulfate deposits in the miocene messinian onshore of the mediterranean basin appears to be in contrast with the hypothesis of a complete desiccation as a consequence of the salinity crisis below the sea floor the evaporite facies are virtually unknown but the detailed review of the cores from onshore israel cutting through the evaporite filling of the marginal canyons in the levant basin mavqi im formation reveal exclusively clastic sulfate facies the rocks are graded gypsrudite and gypsarenite associated with laminar and cross bedded gypsarenite gypsiltite and shale whereas no primary in situ evaporites are present the clastic facies association is interpreted to have been deposited by subaqueous gravity flows sourced from dismantled selenite rocks originally located eastward and updip of the canyons the absence of supratidal evaporites suggests that no pronounced sea level drop can be inferred during the salinity crisis because the presence of the evaporite layers at different elevations along the canyons cannot mark oscillations in sea level but instead is the result of subaqueous mass wasting phenomena these findings indicate that the other ancient canyons described around the mediterranean basin may not be necessarily related to a base level drop due to basinwide desiccation on the contrary the widespread presence of clastic evaporites suggests that a water body persisted even during the acme of the salinity crisis the clastic deposits onshore israel are the first direct evidence that the widespread lower evaporite unit lying below the floor of the mediterranean may actually consist of deep water resedimented evaporites and that one of the primary sources was originally located on the upper margin of the levant basin if this hypothesis is correct then the mediterranean basin may host the largest clastic sulfate deposit in the world

petrology of a supra subduction zone ophiolite elaz1g turkey the elazig region in eastern taurus turkey exposes paleozoic tertiary metamorphic magmatic and sedi mentary units contacts between the different units are mostly tectonic but there are also primary sedimentary and in trusive contacts the metamorphic rocks of the elazig region are the bitlis puturge and keban malatya massifs which are a single tectonostratigraphic unit that has been tectonically disrupted and fragmented during the upper cretaceous magmatic rocks in the region are represented by ophiolitic units magmatic arc products and young volcanic rocks the sedimentary units are represented by upper cretaceous tertiary marine and lacustrine sedimentary rocks in the study area the metamorphic units are represented by the paleozoic puturge metamorphic rocks composed of phyllite slate mica schist quartz muscovite schist calc schist and low grade metamorphite the ophiolite that is described in this paper is composed of wehrlite pyroxenite gabbro diabase dykes and dykes cutting gabbro these units are cut by the granitic rocks of the upper cretaceous elazig magmatic suite the lithological and geochemical data on the rocks of komurhan ophiolite indicate that these rocks were derived from crystallization of an enriched mid ocean ridge basalt morb type magma the komurhan ophiolite formed in a supra subduction spreading zone during the cretaceous re lated to this event is the north dipping subduction of the southern branch of neo tethys ocean which began spreading in the late triassic the crust was thickened by the development of an island arc and by the thrusting of the puturge metamorphic rocks onto this island arc in response to north south compression during the late cretaceous the magma formed by partial melting of the subducted slab giving rise to granitic rocks that cut the upper parts of the ophiolite the ophiolite and the elazig magmatic suite attained their present position after the middle eocene

oligocene uplift of the western greater caucasus an effect of initial arabia eurasia collision the greater caucasus is europe s largest mountain belt significant uncertainties remain over the evolution of the range largely due to a lack of primary field data this work demonstrates that depositional systems within the oligocene early miocene maykop series on either side of the western greater caucasus wgc display a similar provenance and divergent palaeocurrents away from the range constraining a minimum age for the subaerial uplift of the range as early early oligocene an eocene oligocene hiatus basal oligocene olistostromes and a marked increase in nannofossil reworking also point to initial deformation in the earliest oligocene the initial uplift of the wgc occurred during the final assembly of the tethysides to its south uplift commenced after the late eocene final suturing of northern neotethys and during the initial collision of arabia with the southern accreted margin of eurasia this suggests that compressional deformation was rapidly transferred across the collision zone from the indenting arabian plate to its northern margin

irregular plate boundary controls on foreland basin sedimentation miocene kahramanmaras foreland basin se turkey abstract the northern movement of the arabian plate led to the development of a compressional regime in the south eastern part of turkey after the late cretaceous the collision of the arabian plate with the anatolide taurides platform and subsequent development of the kahramanmaras foreland basin at the beginning of the miocene evolved as a result of this movement an irregular plate geometry or promontory of the arabian plate caused partitioning of the plate margin precollision collision postcollision this irregular plate boundary was delimited by western and northern boundary faults and an interior basin fault the nw oriented small wedge top basins on the overlying anatolide taurides platform obliquely cut through the foredeep basin the region across the wedge top basin on the irregular promontory of the underlying arabian plate contains different sedimentation depocentres small fining upward submarine fan deposits including pebbly channel deposits and coarsening upward lobe sequences are located at the centre of the irregular part of the plate in the tanir region and overlie planktic foraminifera bearing claystones these submarine fan sediments pass outboard into distal interbedded turbidite claystones and siltstones in a downdip direction s se the boundary fault intersection of the promontory led to the development of a submarine slope environment with irregular sea floor topography in the firniz area 4 5 km south east of the tanir region the slump deposits sandy debrites and fine grained thin bedded turbidites filled this region structural alignments and seismicity associated with the plate margin were the main controlling factors on the geometry of the depocentre sediment quantity sediment input sedimentary facies local sea level changes and post sedimentary deformation in the kahramanmaras foreland basin

new evidence and solution to the maden complex controversy of the southeast anatolian orogenic belt turkey the volcanosedimentary units of late mesozoic tertiary age that outcrop in the southeast anatolian orogenic belt are commonly referred to as the maden complex there is a long lasting controversy over its definition age stratigraphic and structural position and the origin and thus the orogenic evolution to solve this problem large strips across the southeast anatolian orogenic belt have been studied extensively and different rock groups which were regarded previously as the maden unit have been differentiated their major characteristics and differences have been identified the maden unit sensu stricto is here redefined as a volcanosedimentary succession of middle eocene age representing a short lived back arc basin which reached the stage of an embryonic ocean presently the maden group occurs mainly within the lower nappe stack of the nappe zone of the southeast anatolian orogen it rests stratigraphically on an amalgamated nappe package consisting of the different metamorphic tectonic units and in turn is overlain tectonically by the upper nappe units

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

petrogenesis of the post collisional volcanic rocks from the borcka artvin area implications for the evolution of the eocene magmatism in the eastern pontides ne turkey abstract whole rock geochemistry 40 ar 39 ar data and sr nd isotopes are presented for the eocene borcka volcanic rocks on the eastern corner of the eastern pontide orogenic belt ne turkey borcka artvin volcanic rocks are divided into three suites basic dyke borcka basalt and civankoy suite these rocks contain plagioclase an 49 88 clinopyroxene wo 38 49 en 38 54 fs 8 25 hornblende mg 0 57 0 74 phenocrysts and magnetite titanomagnetite and apatite microphenocrysts 40 ar 39 ar ages on hornblendes ranging from 46 9 0 1 to 39 9 0 5 ma within the middle eocene the volcanic rocks show tholeiitic calc alkaline affinities and have low to medium k contents they are enriched in large ion lithophile lile and light rare earth elements lree with pronounced depleted high field strength elements hfse the chondrite normalized ree patterns la cn lu cn 1 19 show low to medium enrichment indicating similar sources for the rock suite initial 87 sr 86 sr values 87 sr 86 sr 46 ma vary between 0 70423 and 0 70495 while initial 143 nd 144 nd values 143 nd 144 nd 46 ma lie between 0 51263 and 0 51285 the main solidification processes involved in the evolution of the volcanics consist of fractional crystallization with minor amounts of crustal contamination all our evidences support the conclusion that the parental magma of the rocks probably derived from an enriched mantle previously metasomatized by fluids derived from subducted slab in a post collisional extension related geodynamic setting