apatite fission track data for the miocene arabia eurasia collision the collision between the eurasian and arabian plates along the 2400 km long bitliszagros thrust zone isolated the mediterranean from the indian ocean and has been linked to extension of the aegean rifting of the red sea and the formation of the north and east anatolian fault systems however the timing of the collision is poorly constrained and estimates range from late cretaceous to late miocene here we report the fi rst apatite fi ssiontrack aft ages from the bitlis zagros thrust zone the aft samples are distributed over the 450 km length of the bitlis thrust zone in southeast turkey and include metamorphic rocks and eocene sandstones despite the disparate lithology and large distance the aft ages point consistently to exhumation between 18 and 13 ma the aft ages along with a critical appraisal of regional stratigraphy indicate that the last oceanic lithosphere between the arabian and eurasian plates was consumed by the early miocene ca 20 ma the results imply that aegean extension predated the arabia eurasia collision

late palaeogene neogene evolution of the triple junction region near maras south central turkey the marao region of turkey includes the anatolian arabian african triple junction the african arabian margin is marked by left lateral transtension along the dead sea kara su rift motion on the anatolian arabian boundary is partitioned between the left lateral east anatolian fault and a fold thrust belt termed the engizek zone equivalent to the bitlis suture further east the african anatolian boundary lies along the cyprus misis andirin trend and is expressed near the triple junction as the aslantao iskenderun zone now undergoing slow left lateral transtension the neogene evolution of these boundaries is largely recorded in the stratigraphy and structure of the basins that lie along the anatolian arabian lice basin and anatolian african aslantao iskenderun basin boundaries these basins appear to have developed in the early miocene along major strike slip zones large half graben in the pre neogene 9basement9 of the western misis andirin block developed contemporaneously with motion on the anatolian african boundary these extensional features evolved subsequent to the intense shattering of the mesozoic carbonate sequence in the misis andirin block and its mixing with panels of deep water palaeogene strata to form an extensionally disrupted assemblage transpression and conversion of both anatolian african and anatolian arabian boundaries to fold thrust belts occurred in the late miocene transpression continues along the anatolian arabian boundary but transtension has recurred along the anatolian african boundary since the pliocene

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

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

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

retrodeforming the arabia eurasia collision zone age of collision versus magnitude of continental subduction the arabia eurasia collision has been linked to global cooling the slowing of africa mediterranean extension the rifting of the red sea an increase in exhumation and sedimentation on the eurasian plate and the slowing and deformation of the arabian plate collision age estimates range from the late cretaceous to pliocene with most estimates between 35 and 20 ma we assess the consequences of these collision ages on the magnitude and location of continental consumption by compiling all documented shortening within the region and integrating this with plate kinematic reconstructions shortening estimates across the orogen allow for 350 km of neogene upper crustal contraction necessitating collision by 20 ma a 35 ma collision requires additional subduction of 400 600 km of arabian continental crust using the oman ophiolite as an analogue ophiolitic fragments preserved along the zagros suture zone permit 180 km of subduction of the arabian continental margin plus overlying ophiolites wholesale subduction of this more dense continental margin plus ophiolites would reconstruct 400 500 km of postcollisional arabia eurasia convergence consistent with a ca 27 ma initial collision age this younger arabia eurasia collision suggests a noncollisional mechanism for the slowing of africa and associated extension

discovery of the late triassic middle carnian rhaetian radiolarians in the volcano sedimentary sequences of the kocali complex se turkey correlation with the other tauride units abstract the kocali complex in se turkey includes pelagic sediments pelagic limestones cherts etc basic volcanic rocks of oceanic crust origin together with platform derived sediments its depositional age was previously assigned as late jurassic early cretaceous in order to study the radiolarian contents of volcano sedimentary sequences in this complex six stratigraphic sections have been measured mainly at the ne and nw adiyaman city radiolarian faunas from these stratigraphic sections reveal that the age of these sequences ranges from middle carnian to rhaetian based on these data the depositional age of the complex is older than the previously assigned lithological characteristics widespread triassic basic volcanic rocks associated with pelagic sediments and radiolarian contents of these sequences have close similarities with the sequences of the alakircay nappe of the antalya nappes in western and central taurides based on taxonomic studies 99 taxa have been determined of which one genus adiyamanium and four species monocapnuchosphaera kocaliensis paronaella speciosa ferresium okuyucui and adiyamanium crassum are described as new

periodic deformation of oceanic crust in the central indian ocean new seismic reflection profiles of 5370 km running through the ocean drilling program leg 116 sites and deep sea drilling project sites 215 and 218 were obtained to investigate the spatial extent timing and nature of the tertiary deformation of the equatorial central indian ocean analyses of the data revealed basement and sedimentary structures and structural unconformities that resulted from the release of compressional forces long wavelength 150 300 km anticlinal basement structures with 1 2 km relief and tight folding and high angle faulting 5 20 km long of oceanic basement and overlying sediments exist between the afanasy nikitin seamount and the ninety east ridge the deformation zone extends from 10 s to the north up to 7 n latitude the changes in the regional basement trend along 87 e longitude between latitudes 11 s and 15 n coincide with the significant tectonic events of the first major plate reorganization occurred in the eastern indian ocean at 90 5 ma and changes in the indian plate motion at 65 5 ma the basement deformation at selected places a widespread unconformity of the upper miocene and subsequent younger unconformities lower pliocene and upper pleistocene indicate that the deformation activity might have begun earlier than the generally believed age of 7 5 ma and appears to be periodic the upper miocene and upper pleistocene deformational unconformities are in general observed south of 1 s while the basement deformation and lower pliocene deformational unconformity are mostly present in the area north of 1 s it is surmised that the compressional stresses built up since the hard collision of india with eurasia may have released for a short period prior to the early miocene time and deformed the oceanic basement in the northeastern indian ocean thereafter the stress regime seems to have transferred to the north of the indian shield and caused deformation of the continental lithosphere later the activity reoccurred during the late miocene 7 5 ma early pliocene 4 ma and late pleistocene 0 8 ma with a cyclicity of 3 5 m y and deformed the oceanic crust and sedimentary strata in the central indian ocean

dynamics of orogenic wedges and the uplift of high pressure metamorphic rocks subduction accretion complexes can be approximated as wedge shaped continua with a rigid buttress behind and a subducting litho spheric slab beneath thick wedges undergoing prograde metamorphism have a negligible long term yield strength and are likely to exhibit a complex nonlinear viscous rheology such a wedge will tend to deform internally until it reaches a stable configuration in which the gravitational forces generated by the wedge geometry balance the traction exerted on its underside by the subducting slab accretion of material at the wedge front will lengthen the wedge and cause it to shorten internally to regain the stable geometry this shortening will be expressed as late out of sequence thrusting backthrusting and folding conversely underplating of sediment or crustal slices will thicken the wedge which may need to extend internally to regain stability extension will cause listric normal faults that may merge downward into zones of ductile extension continued underplating at depth and compensating extension above provides a mechanism for bringing high p low t metamorphic rocks to upper levels in the rear of the wedge where they are commonly observed many major tectonic boundaries in convergent orogens such as the coast range thrust in the franciscan complex major nappe contacts in the alps and the contact between the nevado filabride and higher betic nappe complexes in the betic cordillera show abrupt increases in metamorphic grade downward across them this is consistent with their origin or reactivation as uplift related extensional structures

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

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

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

sedimentology of a late cenozoic collisional sequence the misis complex adana southern turkey abstract this study is concerned with miocene sequences formed within part of the cukurova basin of southern turkey a major downwarp created during the early stages of collision between the afro arabian plate and the tauride anatolian microplate assemblage we report here the results of a combined stratigraphical sedimentological structure and geochemical study of the misis complex a structurally elevated segment of cukurova basin fill this analysis has demonstrated the structurally imbricated nature of the misis sequences and the tectonic juxtaposition of originally well separated coeval facies the initial discernible phase of basin filling pre burdigalian was marked by deep marine conditions and marginal tectonic instability probably related to a late phase of tauride nappe advance the subsequent phase of crustal extension burdigalian early tortonian produced expansion of the cukurova basin limits and an upwards shoaling succession in which sediment transport towards the southwest gradually became dominant as a result of earlier suturing and uplift in northeasterly sectors of the collision zone the miocene arenites of the misis complex are petrographically diverse with common siliciclastic and carbonate detrital admixtures and mineralogically immature and their position in petrotectonic fields indicates a compound provenance from both recycled orogen and magmatic arc sources a noteworthy petrographic feature is the compositional similarity of arenites from both shallow and deep marine facies the general succession of neogene facies observed in the cukurova basin and misis complex is consistent with their evolution within a perisutural foreland basin but this interpretation is complicated by petrographic and geochemical features attributed to remnants of an older magmatic arc later stages of basin filling are also marked by the local occurrence of anomalous palaeoenvironmental associations including olistostromic units attributed to contemporaneous intra basinal tectonism

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

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

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

late triassic rifting and jurassic cretaceous passive margin development of the southern neotethys evidence from the adiyaman area se turkey evidence of rifting and continental break up to form the s neotethys is found within the volcanic sedimentary kocali complex this is a folded thrust imbricated succession that includes lavas volcaniclastic sediments pelagic carbonates radiolarites and manganiferous deposits interbedded ribbon cherts contain radiolarians of late triassic to late jurassic age the lower part of the succession of mid late triassic age tarasa formation is dominated by enriched mid ocean ridge basalt e morb the overlying late triassic to mid jurassic interval konak formation is characterised by intercalations of ocean island basalt and e morb taking account of structural position the basalts erupted within the outer part of a continent ocean transition zone continental break up probably occurred during the late triassic carnian norian early to mid jurassic lavas and volcaniclastic sediments record volcanism probably after continental break up in addition the karadut complex is a broken formation that is located at a relatively low structural position just above the arabian foreland pelagic carbonates redeposited carbonates and radiolarites predominate radiolarians are dated as early to mid jurassic and late cretaceous in age the pelagic carbonates include planktic foraminifera of late cretaceous age the karadut complex resulted from the accumulation of calcareous gravity flows pelagic carbonate and radiolarites in a relatively proximal base of slope setting after continental break up morb and ophiolitic rocks formed within the s neotethys further north tectonic emplacement onto the arabian platform took place by earliest maastrichtian time regional interpretation is facilitated by comparisons with examples of triassic rifting and continental break up in the eastern mediterranean region and elsewhere

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