a new approach to the opening of the eastern mediterranean sea and the origin of the hellenic subduction zone part 1 the eastern mediterranean sea we identify long transform faults that frame the eastern mediterranean sea and that were active during jurassic and probably the early cretaceous during the opening of the central atlantic ocean

idealized simulations of the effect of taiwan and philippines topographies on tropical cyclone tracks the effects of topography on tropical cyclone tc tracks are investigated using the weather research and forecasting model running on a beta plane with actual topography two sets of experiments are performed one focusing on taiwan topography and the other on the philippines in each set different parts of the terrain are set to be either present or absent and the tcs are inserted at a location southeast of the mountain so that landfall occurs at the central part of the mountain in the no terrain control cases relative to the control case a pair of terrain induced gyres is found in all with terrain experiments this pair of gyres rotates cyclonically around the tc and the gyre associated flow near the tc centre causes a northward deflection of the tc track prior to landfall an examination of the potential vorticity tendencies pvts suggests that in addition to the pvt produced by this flow the pvt from diabatic heating cannot be ignored in explaining the tc track during landfall the asymmetric diabatic heating is significant which tends to retard the fast displacement of the tc caused by horizontal advection this diabatic heating distribution results from three different mechanisms an incursion of dry air from the mountain low level convergence induced by the terrain altered wind field in the southwestern part of the tc and the development of convergence cyclonically inward from the eastern side of the mountain to the tc core however the first two mechanisms are apparently missing in the philippine experiments because of the lower height and the moister air over the mountains on luzon island

methodology of the last climatic cycle reconstruction in france from pollen data abstract a numerical method has been devised to reconstruct the climate of the last climatic cycle from pollen data reliable annual reconstructions have been published recently for the two french long sequences of la grande pile and les echets covering the last 140 millennia this paper gives more details on the method used it proposes new reconstructions based on an extended modern pollen data base these reconstructions are consistent with the previous ones especially detailed information is obtained on the seasonal characteristics of climate computations of gcm on the climate variations from 125 kyr to 115 kyr b p are confirmed for western europe the insolation variations have induced at that time a decrease of seasonality accompanied by an increased cyclonic activity in winter this has been the beginning of the first ice growth after the last interglacial other glacier growth phases are detected at the end of substage 5c and particularly at the end of substage 5a

theory of quantitative reconstruction of vegetation i pollen from large sites reveals regional vegetation composition quantitative reconstruction of past vegetation is one of the primary goals in quaternary palynology and palaeoecology but still remains difficult this paper proposes a model reveals that estimates regional vegetation composition using pollen from large lakes that have small site to site variations of pollen assemblages even if vegetation is highly heterogeneous once these data have been used to quantify regional vegetation composition within 104 105 km2 background pollen one of the parameters crucial for vegetation reconstruction can be estimated for smaller sized sites and incorporated into the landscape reconstruction algorithm lra a multistep framework for quantitative reconstruction of vegetation in smaller areas 104 ha simulations using the pollscape modelling show that reveals can provide accurate estimates of regional vegetation composition in various landscapes and under different atmospheric conditions if pollen assemblages from lakes that are much smaller than large lakes a

comparative petroleum systems analysis of the interior basins of turkey implications for petroleum potential abstract the interior basins of turkey remain effectively unexplored and their petroleum systems are poorly understood this paper presents a comparative summary of the geological evolution petroleum potential and prospectivity of the central tuz golu sivas and cankiri and east anatolian mus hinis pasinler horasan and tercan askale basins using geological seismic geochemical and petrophysical data and a series of quantitative basin models the studied basins are ranked on the basis of source effectiveness reservoir quality seal efficiency and the timing of hydrocarbon expulsion and migration relative to trap formation a qualitative risk assessment based on the elements of the petroleum system is used to evaluate the likelihood of hydrocarbon discovery in each of the basins this study shows that the chance of hydrocarbon discovery in the east anatolian basins is unlikely very unlikely and tuz golu sivas and cankiri basins are equally likely unlikely unlikely likely and unlikely respectively heavy oil and minor gas associated with two mature petroleum systems were discovered in the tuz golu basin various trap forming mechanisms such as salt tectonics and middle eocene compression accompanied by the effective sealing capacity of the eocene evaporites favor the hydrocarbon exploration potential of the tuz golu basin the highest exploration risk in the tuz golu basin arises from the poor quality sandstone reservoirs the biggest risk factor in the eastern anatolian basins is insufficient thermal maturity despite the presence of good quality source rocks the sivas basin is one of the most promising interior basins of turkey due to the presence of multiple mature petroleum systems and high quality reservoirs there is a high chance of accumulation of multi phase hydrocarbons in the eocene and miocene traps the major problem in the sivas basin is the lack of an efficient seal rock the cankiri basin contains all of the necessary elements of an ideal petroleum system except the presence of an organic rich source rock thus the chance of hydrocarbon discovery in the cankiri basin is low

late cretaceous palaeocene subduction collision exhumation of a microcontinent along the northern active margin of the southern neotethys evidence from the alanya massif and the adjacent antalya complex s turkey abstract the alanya massif represents a microcontinent that underwent subduction exhumation related to collision with the larger tauride microcontinent to the north during latest cretaceous palaeocene intermediate structural level blueschist melange in the northwest gundogmus area encompasses ductile deformed meta basaltic rocks meta cherts and minor serpentinite in a lower grade meta mudrock matrix the meta basaltic protoliths mainly formed in a subduction influenced setting together with less common oib and e morb late permian platform slope carbonates were intersliced during late stage brittle thrusting and directly over ridden by a lower grade greenschist facies late permian early triassic aged platform unit the blueschist melange is interpreted as an oceanic subduction complex that was obducted southwards related to microcontinental collision intermediate structural level hp lt blueschist ecologites farther south alanya area indicate that the alanya massif represents variably subducted exhumed continental crust both subduction and exhumation took place during the latest cretaceous prior to late palaeocene early eocene marine transgression late precambrian protoliths of eclogitic hp lt rocks and also similar aged amphibolite facies meta basic intrusions farther southeast anamur area are interpreted to have formed in a panafrican cadomian late stage back arc setting late triassic basaltic rocks in the antalya complex structurally beneath and to the north erupted in a rift setting we restore the mesozoic palaeogeography from north to south as tauride microcontinent antalya rift basin alanya micrcontinent s neotethys the subduction exhumation history may serve as a model for similar active margin collisional settings elsewhere

petrology of the ispendere malatya ophiolite from the southeast anatolia implications for the late mesozoic evolution of the southern neotethyan ocean

eastern turkish high plateau as a small turkic type orogen implications for post collisional crust forming processes in turkic type orogens abstract post collisional magmatism may be generated by extensive crustal melting in tibet type collisional environments or by falling out of slabs from under giant subduction accretion complexes in turkic type collisional orogens giving rise to decompression melting of the asthenospheric mantle replacing the removed oceanic lithosphere in turkic type post collisional magmatism the magmatic products are dominantly alkalic to peralkalic and greatly resemble those of extensional regions giving rise to much confusion especially in interpreting old collisional orogenic belts such magmatic regions are also host to a variety of economically valuable ore deposits including gold one place in the world where today active turkic type post collisional magmatism is present is the eastern anatolian high plateau produced after the terminal arabia eurasia collision in the late miocene the plateau is mostly underlain by the late cretaceous to oligocene east anatolian accretionary complex which formed south of the rhodope pontide magmatic arc this subduction accretion complex has been further shortening since the collision but it has also since been domed and became almost entirely covered by at least 15 000 km3 of volcanic rocks the volcanic rocks are calc alkalic in the north transitional in the middle and alkalic in the south of the plateau where the crust is thinnest today less than 38 km the volcanics are derived almost entirely from an enriched mantle the ages of the volcanics also become younger from north to south from about 11 ma to possibly 17th century ad we interpret the origin of the magmatic rocks as the result of decompression melting of the asthenospheric mantle sucked towards the exposed base of the east anatolian accretionary complex as the oceanic lithosphere beneath it fell out the lower density of the hot asthospheric material was the cause of the doming we believe that similar processes dominated the post collisional tectonics of such vast turkic type orogens as the altaids of central asia the late devonian early carboniferous lachlan belt in southeastern australia and the pan african collage of northeast afro arabia it is likely that archaean collisions were dominated by turkic type post collisional events rather than tibetan ones that only became common in the proterozoic

southward migration of arc magmatism during latest cretaceous associated with slab steepening east pontides n turkey new paleomagnetic data from the amasya region abstract a new paleomagnetic study was carried out on the findikli formation in the amasya region which is to the north of the ankara erzincan neotethyan suture zone in order to better understand the paleogeographic evolution of the pontides tectonic belt during the maastrichtian samples were collected from volcanoclastic sandstones and lavas at 51 sites rock magnetic experiments identified pseudo single domain psd titanomagnetite as the main magnetic carriers at the majority of sites progressive thermal and alternating demagnetization revealed that the characteristic remanent component is removed between 400 and 580 c or 20 100 mt respectively a high temperature component which indicates the presence of titano hematite is found only in some lavas declinations show a systematic dispersion across the study area related to tectonic rotations about vertical axes inclinations are consistent however and yield a mean paleolatitude of 20 0 n 2 5 for the maastrichtian comparison of the results from this study with the reference direction of the east pontides from the turonian campanian is best explained with a model involving slab roll back and marginal basin formation between 90 and 65 ma period

evidence of late cretaceous oroclinal bending in north central anatolia palaeomagnetic results from mesozoic and cenozoic rocks along the izmir ankara erzincan suture zone

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

geology and isotope geochemistry c o s of the diyadin gold deposit eastern turkey a newly discovered carlin like deposit abstract diyadin mineralization is the first reported gold deposit located in a collisional tectonic environment in eastern anatolia the mineralization is related to n s and n10 20 w trending fault systems and hosted within the paleozoic metamorphic basement rocks of the anatolide toride microcontinent calc schist dolomitic marble and miocene and quaternary volcanic rocks comprise the exposed units in the mineralized area geochemical signatures alteration types and host rock characteristics of the diyadin gold deposit resemble those of carlin type deposits mineralization is constrained by alteration of overlying volcanic rocks to younger than 14 ma k ar carbon and oxygen stable isotope measurements of carbonate rocks were made on six drill holes n 81 with an additional four samples of fresh carbonate rocks from surface outcrops background carbonate rocks have 13cv pdb 1 8 and 18ov smow 27 isotopically altered host rock samples have decreased 18o down to 11 4 and variable 13c from 3 6 to 4 8 postore carbonate veins and cave fill material have distinctly different isotopic signatures particularly carbon from 13c 8 4 to 9 8 whether this post ore carbonate is simply very late in mineralization associated with the gold system or is a completely different younger system utilizing the same pathways is unclear at present within the host rock sample set there is no correlation between gold and 13c and a weak correlation between gold and 18o indicative of water rock interaction and isotopic alteration both the isotopic data and structural mapping suggest that the main upflow zone for the deposit is near the northern portion of the drill fence additional data at multiple scales are required to clarify the relationship s between fluid flow and mineralization

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

morphology displacement and slip rates along the north anatolian fault turkey 1 geological and geomorphological offsets at different scales are used to constrain the localization of deformation total displacement and slip rates over various timescales along the central and eastern north anatolian fault naf in turkey the naf total displacement is reevaluated using large rivers valleys 80 15 km and structural markers pontide suture 85 25 km tosya vezirkopru basins 80 10 km these suggest a neogene slip rate of 6 5 mm yr over 13 myr the river network morphology shows offsets at a range of scales 20 m to 14 km across the main fault trace and is also used to estimate the degree to which deformation is localized at a smaller scale the morphology associated with small rivers is offset by 200 m along the naf the age of these features can be correlated with the holocene deglaciation and a slip rate of 18 3 5 mm yr is determined this is consistent with a rate of 18 5 mm yr deduced independently from the 14c dating of stream terrace offsets over the short term gps data gives a similar rate of 22 3 mm yr all our results tend to show that most of the deformation between the anatolian and eurasian lithospheric plates has been accommodated along or very close to the active trace of the naf the difference between the neogene and the holocene slip rate may be due to the recent establishment of the current plate geometry after the creation of the naf

satellite and pollen based quantitative woody cover reconstructions for northern asia verification and application to late quaternary pollen data abstract accurate reconstruction of late quaternary vegetation cover is necessary for better understanding of past vegetation dynamics the role of vegetation feedbacks in glacial interglacial climate variations and for validating vegetation and climate models in this paper over 1700 surface pollen spectra from the former soviet union mongolia northern china and northern japan together with data from the advanced very high resolution radiometer avhrr were used to calibrate modern analogue method for quantitatively reconstructing past woody cover from fossil pollen data the avhrr based estimates of woody cover percentages within a 21 21 km window around pollen sampling sites were attributed to the respective modern pollen spectra reconstructions of modern woody cover using the pollen data and best modern analogues bma method matched well to the original avhrr based estimates for both total woody cover r 2 0 77 and its fractions including broad leaved r 2 0 66 needle leaved r 2 0 79 deciduous r 2 0 60 and evergreen r 2 0 76 woody cover discrepancies in the pollen avhrr cross validation may be caused by long distance transport of arboreal pollen patchy forest distributions underrepresentation of larix and populus in pollen records and errors in the avhrr classification the generally strong correlations encourage application of the modern analogue approach for reconstructing late quaternary variations in vegetation cover from northern asian fossil pollen records at the last glacial maximum lgm 21 000 cal yr bp areas presently occupied by boreal forest were much more open suggesting a reduction in total woody cover to below 20 at most modern forest sites pollen records from northern and central siberia suggest a rather quick spread of tree and shrub vegetation after 15 000 cal yr bp presumably in response to increased summer insolation woody cover histories are spatially variable in the modern forest steppe where tree growth is largely controlled by the ratio of annual actual over potential evapotranspiration which serves as an index of moisture availability in northwestern mongolia woody cover percentages decreased between 9000 and 5000 cal yr bp and again between 2000 and 1000 cal yr bp and may be linked to shifts in intensity of the pacific monsoon in contrast pollen data from the kazakhstan forest steppe where atmospheric precipitation is associated with the atlantic westerly flow suggest that woody cover density reached modern levels only during the last millennium

the effect of hawai i s big island on track and structure of tropical cyclones passing to the south and west abstractthe effect of the big island of hawai i on tropical cyclone tc track and structure is investigated using the weather research and forecasting wrf model the high 4000 m mountains of the big island modulate lower tropospheric flow in such a way that it can influence tcs hundreds of kilometers away from the island when a tc approaches from the east the blocking of lower tropospheric flow leads to a slowing of the tc s movement as a tc passes close to the south side of the big island it deviates southward the tc core convection and winds can become axisymmetric because of the blocking of the stronger northeasterly flow to the north of the storm the authors hypothesize that this axisymmetrization led to the unexpected eye formation of hurricane flossie 2007 just southeast of the big island as a tc moves into the lee southwest side of the big island the flow associated with the island wake leads to a track deviated to the right the hurricane dot 1959 simulations suggest that this

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

block and shear zone architecture of the minnesota river valley subprovince implications for late archean accretionary tectonics the minnesota river valley subprovince of the superior province is an archean gneiss terrane composed internally of four crustal blocks bounded by three zones of east northeast trending linear geophysical anomalies two of the block bounding zones are verified regional scale shears the geological nature of the third boundary has not been established potential field geophysical models portray the boundary zones as moderately north dipping surfaces or thin slabs similar in strike and dip to the morris fault segment of the great lakes tectonic zone at the north margin of the subprovince the central two blocks of the subprovince morton and montevideo are predominantly high grade quartzofeldspathic gneiss some as old as 3 6 ga and late tectonic granite the northern and southern blocks benson and jeffers respectively are judged to contain less gneiss than the central blocks and a larger diversity of syntectonic and late tectonic plutons a belt of moderately metamorphosed mafic and ultramafic rocks h

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

a numerical study of the track deflection of supertyphoon haitang 2005 prior to its landfall in taiwan abstract a series of numerical simulations are conducted using the advanced research version of the weather research and forecasting model with a 4 km fine mesh to examine the physical processes responsible for the significant track deflection and looping motion before the landfall of supertyphoon haitang 2005 in taiwan which poses a unique scientific and forecasting issue in the control experiment a low level northerly jet induced by the channeling effect forms in the western quadrant of the approaching storm where the inner core circulation is constrained by the presence of taiwan s terrain because of the channeling effect the strongest winds of the storm are shifted to the western portion of the eyewall the northerly advection flow averaged asymmetric winds within 100 km radius results in a sharp southward turn of the westward moving storm the time series of the advection flow shows that the advection wind vectors rotate cyclonically in time and well match the motion of the simulated vortex

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

late palaeozoic early cenozoic tectonic development of southern turkey and the easternmost mediterranean region evidence from the inter relations of continental and oceanic units

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

the petrogenesis of saricimen caldiran van quartz monzodiorite implication for initiation of magmatism late medial miocene in the east anatolian collision zone turkey abstract the saricimen porphyry is exposed as a sub volcanic pluton within the upper cretaceous ophiolitic rocks in east anatolian accretionary complex the pluton is quartz monzodioritic in composition consisting of feldspar hornblende and biotite phenocrysts set in a fine grained matrix major element geochemistry indicates the pluton is of high k calc alkaline metaluminous character with a low 0 81 0 90 aluminum saturation index asi trace element and sulfur isotope geochemistry suggests that the saricimen porphyry was mantle derived and contaminated by crustal materials during ascent tectonically this and related volcanic and plutonic rocks in eastern turkey and iran are subduction related and comprise the earliest documented neotectonic igneous activity associated with the final closure of the neo tethys between the arabian and eurasia plates at 14 13 ma

structure of the kizildag ophiolite a slow spread cretaceous ridge segment north of the arabian promontory the cretaceous kizildag ophiolite in southern turkey is part of the neotethyan ophiolite belt around the arabian promontory and consists of two structurally distinct massifs that are separated by a northwest striking high angle oblique fault this fault is interpreted as an accommodation zone that permitted differential movements between the adjacent crustal blocks during the evolution of the ophiolite the main massif to the west includes an antiformal peridotite core adjoined on the southeast by the normal fault bounded plutonic sequence and sheeted dike complex which collectively form a structural graben reminiscent of slow spreading ridge axes the inferred spreading axis and axis parallel fault contacts are intersected and offset at right angles by tear faults that are geometrically and kinematically analogous to transfer faults in modern oceanic lithosphere at slow spreading ridge environments the secondary massif to the east consists mainly of serpentinized peridotites directly overlain along tectonic and or intrusive contacts by lava flows rotated dike blocks and plutonic rocks and can be interpreted as a segment of oceanic lithosphere evolved at and near the accommodation zone the general structure of the ophiolite suggests its evolution via magmatic accretion and subsequent tectonic extension along a low angle shear zone at a slow spreading ridge environment

low froude number flow past three dimensional obstacles part i baroclinically generated lee vortices abstract we study the flow of a density stratified fluid past a three dimensional obstacle using a numerical model our special concern is the response of the fluid when the froude number is near or less than unity linear theory is inapplicable in this range of froude number and the present numerical solutions show the rich variety of phenomena that emerge in this essentially nonlinear flow regime two such phenomena which occupy parts i and ii of this study are the formation of a pair of vertically oriented vortices on the lee side and a zone of flow reversal on the windward side of the obstacle the ice vortices have been explained as a consequence of the separation of the viscous boundary layer from the obstacle however this boundary layer is absent by design in the present experiments and lee vortices still occur we argue that a vertical component of vorticity develops on the lee side owing to the tilting of horizontally oriented vorticity produced baroclinically as the isentropes deform in r

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

petrology and phase relations of the kyanite eclogites from eastern turkey eclogites are found as lenses or layers in the precambrian gneiss terrain of the bitlis massif in eastern turkey kyanite eclogites from the region of gablor hill in the bitlis massif exhibit relatively minor alteration and consist of garnet omphacite kyanite zoisite calcic amphibole phengite rutile and quartz in terms of geological setting and mineral compositions gablor eclogites are very similar to eclogites from high grade gneiss terrains metamorphic conditions during the eclogite crystallisation are determined as 625 35 c and 16 3 kbars the coexistence of white mixa omphacite and kyanite constrains a text h text 2 text o between 0 4 and 1 primary calcic amphiboles from the gablor eclogites exhibit conflicting textures indicating stable coexistence with as well as growth from omphacite and garnet this is explained by a buffering reaction between amphibole garnet omphacite zoisite and kyanite during the eclogite crystallisation whereby a text h text 2 text o is controlled and buffered by the mineral assemblage

mantle flow induced crustal thinning in the area between the easternmost part of the anatolian plate and the arabian foreland e turkey deduced from the geological and geophysical data abstract eastern anatolia consisting of an amalgamation of fragments of oceanic and continental lithosphere is a current active intercontinental contractional zone that is still being squeezed and shortened between the arabian and eurasian plates this collisional and contractional zone is being accompanied by the tectonic escape of most of the anatolian plate to the west by major strike slip faulting on the right lateral north anatolian transform fault zone natfz and left lateral east anatolian transform fault zone eatfz which meet at karliova forming an east pointing cusp the present day crust in the area between the easternmost part of the anatolian plate and the arabian foreland gets thinner from north ca 44 km to south ca 36 km relative to its eastern eahp and western sides central anatolian region this thinner crustal area is characterized by shallow cpd 12 16 km very low pn velocities

numerical simulation of typhoon gladys 1994 and its interaction with taiwan terrain using the gfdl hurricane model abstract numerical integrations using the geophysical fluid dynamics laboratory gfdl hurricane model were performed to study the evolution of typhoon gladys 1994 and its interaction with the taiwan terrain consistent with most previous studies the taiwan topography results in the deceleration of gladys s translation speed and southward deviation as it approaches taiwan on the other hand gladys accelerates northwestward while passing taiwan which is likely to be related to the moist processes and differs from the track pattern in the dry model of lin et al although the gfdl hurricane model forecast underestimates gladys s intensity the model can capture the evolution of gladys s intensity especially its weakening during landfall which is primarily due to the cutoff of the water vapor supply in the boundary layer as gladys approached the taiwan terrain other mesoscale phenomena including the pattern of heavy precipitation and the formation of secondary lows are well simulated by the model

tectonic significance of the geochemistry and petrology of ophiolites in southeast anatolia turkey abstract the southeast anatolian ophiolites form discontinuous linear belts of oceanic fragments immediately north of the bitlis zagros suture which marks a continental collision zone between the arabian platform to the south and the taurides to the north the late cretaceous ophiolites in the southeast anatolia are represented by the kizildag in the hatay area the goksun and the berit to the north of kahramanmaras ispendere in the malatya area and komurhan guleman in the elazig area the goksun berit ispendere komurhan and guleman ophiolites were attached to the base of the tauride platform i e the malatya keban along its northern active margin and intruded by the i type calc alkaline granitoids of late cretaceous age in contrast the kizildag hatay ophiolite was thrust over the arabian passive margin in the south the cumulate rocks in the ophiolites are represented by dunite wehrlite lherzolite olivine clinopyroxenite olivine gabbronorite olivine gabbro gabbronorite and gabbro highly magnesian olivines fo88 to 74 and pyroxenes mg 95 to 60 as well as highly calcic plagioclases an95 to 68 from the cumulate rocks differ from oceanic equivalents which mainly formed from a mor basaltic melt the order of crystallization in mineral phases whole rock and mineral chemistry data from the cumulates suggest that the primary magma is compositionaly similar to that observed in modern island arc tholeiitic sequences the volcanic and subvolcanic rocks exhibit tholeiitic compositions chondrite normalized ree n morb normalized multi element patterns and tectonic discrimination diagrams suggest the existence of two main types of parental basic magmas in the crustal rocks of the se anatolian ophiolites these are i iat series that characterize the kizildag goksun ispendere komurhan and guleman ophiolites and ii low ti boninitic series known only in the kizildag ophiolite the geochemistry of the crustal rocks suggests that they formed in a suprasubduction zone tectonic setting including arc forearc environments in the southern neotethys these well preserved plutonic oceanic crustal remnants mainly exhibit an intact ophiolite pseudostratigraphy and are overlain by a volcanic sedimentary unit made up of alternations of basic to acidic extrusive rocks debris flows volcaniclastic sandstones and pelagic limestones interpreted as a tholeiitic ensimatic island arc assemblage built on the suprasubduction zone type crust the metamorphism of some of the ophiolites i e berit in the se anatolia might be related to later stages of intraoceanic subduction during the evolution of the southern neotethys

stratigraphy and tectono sedimentary evolution of the upper cretaceous tertiary sequence in the southern part of the malatya basin east anatolia turkey abstract the malatya basin is situated on the southern taurus anatolian platform the southern part of the basin contains a sedimentary sequence which can be divided into four main units each separated by an unconformity from base to top these are 1 permo carboniferous 2 upper cretaceous lower paleocene 3 middle upper eocene and 4 upper miocene the upper cretaceous tertiary sedimentary sequence resting on basement rocks is up to 700 m thick the permo carboniferous basement consist of dolomites and recrystallized limestones the upper cretaceous lower paleocene transgressive regressive sequence shows a transition from terrestrial environments via lagoonal to shallow marine limestones to deep marine turbiditic sediments followed upwards by shallow marine cherty limestones the marine sediments contain planktic and benthic foraminifers indicating an upper campanian maastrichtian and danian age the middle upper eocene is a transgressive regressive sequence represented by terrestrial and lagoonal clastics shallow marine limestones and deep marine turbidites the planktic and benthic foraminifers in the marine sediments indicate a middle upper eocene age the upper miocene sequence consists of a reddish brown conglomerate sandstone mudstone alternation of alluvial and fluvial facies during late cretaceous early paleocene times the gunduzbey group was deposited in the southern part of a fore arc basin simultaneously with volcanics belonging to the yuksekova group during middle late eocene times the yesilyurt group was deposited in the northern part of the maden basin and the helete volcanic arc the middle upper eocene malatya basin was formed due to block faulting at the beginning of the middle eocene time during the late paleocene early eocene and at the end of the eocene the study areas became continental due to the southward advance of nappe structures the rock sequences in the southern part of the malatya basin may be divided into four tectonic units from base to top the lower allochthon the upper allochthon the parautochthon and autochthonous rock units

comprehensive geochemical correlation between surface and subsurface hydrocarbon occurrences in the batman mardin şirnak area se turkey abstract southeast turkey is the main oil producing region of the country located at the northwestern part of the zagros basin in this study we investigated the geochemical characteristics of both surface and subsurface hydrocarbon occurrences in the batman mardin irnak area in southeast turkey to determine whether a genetic relationship exists between the two for this thirty solid bitumens from twenty two different veins along with ten heavy oils and thirteen oil seepage samples from nearby oilfields and seeps were studied using diverse geochemical tools firstly each of the different hydrocarbon types was considered individually with respect to source organofacies level of thermal maturity and degree of biodegradation the results obtained from the source related parameters demonstrate a marine algal source for all investigated samples also lithology determination based on various diasterane tricyclic terpane hopane and homohopane parameters suggests a carbonate source for all samples except for the dadas and iskar seeps clastic thereafter considering the influences caused by thermal and biological alteration processes all heavy oils less mature solid bitumens as well as the less biodegraded seep oils were selected to be correlated using selected additional parameters homohopane distributions reveal that solid bitumens compared to heavy oils and seeps are highly enriched in c31 and depleted in higher homologues possibly due to cracking of high molecular weight homologues to lower ones during and or after solidification processes furthermore the similarities observed for the relative abundances of six series of aromatic hydrocarbons and their alkylated counterparts substantiate strong genetic affinities within the sample set finally compound specific stable carbon isotopes of individual components show that solid bitumens are more enriched in 13c than the heavy oils which is mainly attributed to the preferential removal of light isotopes 12c during solidification our results strongly confirm that turkish solid bitumens are genetically related to the nearby heavy oils thereby providing new information on the petroleum system in this part of the southeast anatolia

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

interaction of typhoons with the taiwan orography part i upstream track deflections abstract a combined observational and numerical modeling approach is used to study the upstream track deflections of westward moving tropical cyclones approaching the mountainous terrain of taiwan although the standard deviations are large the mean track deflections are larger and have a different orientation for storms approaching the southern end of the island from those approaching the northern end the deflections tend to be larger for weaker and slower moving storms two distinct regions of upstream track deflections that are detected in the observations are explored in a sensitivity study with a 45 km horizontal resolution and 16 layer numerical model as the outer circulation of the tropical cyclone begins to interact with the mountain barrier the zonal decelerations and southward track deflections are explained by an enhanced blocking and deflection of the environmental flow advecting the cyclone the larger effect for southern approaching storms compared to northern storms is because the stron

palynological and avhrr observations of modern vegetational gradients in eastern north america both fossil pollen records and satellite based instruments are remote sensors of earth s vegetation with complementary properties satellites supply spatially continuous and highly resolved images for the past several decades whereas pollen records include local and regional signals of vegetation composition spanning millennia together pollen and satellite based observations measure vegetation change across a broad range of temporal scales here we compare pollen percentages of needleleaved and broadleaved plant taxa to avhrr estimates of percent tree cover for two regions in eastern north america with well defined physiognomic gradients the linear fit between the pollen percentages and percent tree cover is strongest for search window half widths of 25 75 km and unweighted or inverse distance weightings consistent with previous taxon based studies of regional pollen source area and transport variance not explained by the linear model arises primarily from differential properties of the avhrr and

idealized simulations of the effect of taiwan topography on the tracks of tropical cyclones with different steering flow strengths this is the fourth part of a study on the effect of topography on tropical cyclone tc tracks in previous parts idealized simulations were conducted using the weather research and forecasting model to investigate the underlying mechanisms for the upstream deflection and the local and remote topography effect on tcs with different sizes none of these simulations included any background flow in this part uniform easterly steering flows of 5 and 10 m s 1 are introduced to study the track changes under such conditions lee vortices are generated downstream of the taiwan topography by the steering flow the tc terrain induced gyres found in the previous parts also develop when the tc circulation begins to interact with the topography and subsequently dominate over taiwan the cyclonic gyre merges with the cyclonic lee vortex induced by the steering flow and the anticyclonic gyre is advected cyclonically around the tc centre which later deflects the tc because the circulation at the outer radii of a tc competes with the steering flow a smaller tc under a stronger steering flow has to move closer to taiwan in order to generate such gyres this delayed generation of the gyres then leads to the delayed onset of the northward deflection for such a tc for a large tc the circulation at its southern part is weakened by the steering flow so that the track of the anticyclonic terrain induced gyre is changed which results in a larger track deflection of the tc

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

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

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

late cenozoic and modern stress fields in the western fars iran implications for the tectonic and kinematic evolution of central zagros 1 the zagros iran developed during mio pliocene times in response to arabia eurasia convergence the western fars highlights a major bend of the deformation front and displays a remarkable set of nearly n s right lateral strike slip faults the kazerun borazjan karebass sabz pushan sarvestan faults oblique at high angle to the belt the region likely plays a major kinematic role by accommodating the change in shortening modes from partitioned in the western central zagros to nonpartitioned in the eastern zagros the inversion of focal mechanisms from small and moderate earthquakes shows a consistent n020 030 compression with a low ratio between differential stresses this regime accounts for the combination of strike slip and thrust type mechanisms through likely 2 3 permutations fault slip analysis reveals two successive late cenozoic regional compressional trends ne sw then n020 the latter is in good agreement with the present day stress the significance of the ne sw compression is discussed alternatively in terms of stress deviations or block rotations in relation to the strike slip fault system fieldwork and satellite imagery suggest that these faults behave first as transfer faults during folding of the cover and later as strike slip faults in agreement with the succession of stress regimes and the evolution of the dominant deformation style from thin skinned to thick skinned the first order stability of the collision related state of stress since 5 ma supports that the arabia eurasia convergence did not give rise to partitioning in the western fars but rather was and is still accommodated by distributed deformation involving both shortening and strike slip motion throughout the cover and the basement

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

implications of late cretaceous u pb zircon ages of granitic intrusions cutting ophiolitic and volcanogenic rocks for the assembly of the tauride allochthon in se anatolia helete area kahramanmaras region se turkey an assemblage of ne sw trending imbricate thrust slices c 26 km e w long 6 3 km n s of granitic rocks basic felsic volcanogenic rocks helete volcanics ophiolitic rocks meydan ophiolite and melange meydan melange is exposed near the tauride thrust front in se anatolia the volcanogenic rocks were previously assumed to be eocene because of associated nummulitic limestones however ion probe u pb dating of zircons extracted from the intrusive granitic rocks yielded ages of 92 9 2 2 83 1 1 5 ma cenomanian campanian the helete volcanic unit and the overlying meydan ophiolitic rocks both are intruded by granitic rocks of similar age and composition structurally underlying ophiolite related melange includes similar aged but fragmented granitic intrusions major trace element and rare earth element analyses coupled with electron microprobe analysis of the granitic rocks show that they are metaluminus to peraluminus and calc alkaline in composition a magmatic arc setting is inferred from a combination of tectonomagmatic discrimination ocean ridge granite normalized multi element patterns and biotite geochemistry sr nd pb isotope data further suggest that the granitoid rocks were derived from variably mixed mantle and crustal sources granitic rocks cutting the intrusive rocks are inferred to have crystallized at 5 16 km depth the volcanogenic rocks and granitic rocks originated in a supra subduction zone setting that was widely developed throughout se anatolia initial tectonic assembly took place during the late cretaceous probably related to northward subduction and accretion beneath the tauride continent keban and malatya platforms initial tectonic assembly was followed by exhumation and then transgression by shelf depth nummulitic limestones during mid eocene as documented in several key outcrops final emplacement onto the arabian continental margin took place during the early miocene

pollen representation source area and basin size toward a unified theory of pollen analysis abstract the concepts of pollen source area and of production and dispersal biases in pollen representation are quantified by means of a simple theoretical model source areas and relative pollen representation are shown to depend on basin size according to functions that describe the amount of pollen remaining airborne at increasing distances from single pollen sources the form of these functions is determined by physical processes standard formulas for elevated sources do not apply but the integrated form of sutton s equation for particle dispersal from a ground level source gives useful approximations applicable to pollen transport over a forest canopy simulations using this equation yielded source areas that increased realistically with basin size showed substantial differences between source areas for pollen grains with different deposition velocities and predicted that lighter pollen grains should become better represented with increasing basin size all of these predictions are qualitatively consistent with present knowledge of the characteristics of pollen assemblages in different depositional environments the model further allows parameters that can be estimated by statistical calibration methods to be predicted from underlying physical quantities this extension suggests procedures for testing the theory with quantitative data on surface pollen and forest composition preliminary results showed reasonable agreement between estimated and predicted values of dispersal indices for the most abundant taxa in pollen spectra from the northern midwestern united states

orographic influence on a drifting cyclone abstract in this study a primitive equation numerical model is adopted to investigate the orographic influence on a drifting cyclone over an idealized topography similar to that of taiwan for a cyclone propagating from the east and impinging on the central portion of the mountain a northerly surface jet tends to form upstream of the mountain between the primary cyclone and the mountain due to blocking and channeling effects two pressure ridges and one trough are also produced when the cyclone approaches the mountain the low level vorticity and low pressure centers decelerate and turn southward upstream of the mountain due to orographic blocking at the same time the upstream low level vorticity is blocked by the mountain the abrupt increase of surface vorticity and the contraction of cyclone scale on the lee side are explained by the generation of new potential vorticity pv due to wave breaking associated with the severe downslope wind and hydraulic jump the generation of this new pv is evidenc

quantitative interpretation of fossil pollen spectra dissimilarity coefficients and the method of modern analogs abstract dissimilarity coefficients measure the difference between multivariate samples and provide a quantitative aid to the identification of modern analogs for fossil pollen samples how eight coefficients responded to differences among modern pollen samples from eastern north america was tested these coefficients represent three different classes 1 unweighted coefficients that are most strongly influenced by large valued pollen types 2 equal weight coefficients that weight all pollen types equally but can be too sensitive to variations among rare types and 3 signal0to noise coefficients that are intermediate in their weighting of pollen types the studies with modern pollen allowed definition of critical values for each coefficient which when not exceeded indicate that two pollen samples originate from the same vegetation region dissimilarity coefficients were used to compare modern and fossil pollen samples and modern samples so similar to fossil samples were found that most of three late quaternary pollen diagrams could be reconstructed by substituting modern samples for fossil samples when the coefficients indicated that the fossil spectra had no modern analogs then the reconstructed diagrams did not match all aspects of the originals no modern analogs existed for samples from before 9300 yr b p at kirchner marsh minnesota and from before 11 000 yr b p at wintergreen lake michigan but modern analogs existed for almost all holocene samples from these two sites and brandreth bog new york

late cretaceous to middle eocene magmatism and metallogeny of a portion of the southeastern anatolian orogenic belt east central turkey rapidly changing ore deposit types in the late cretaceous and early tertiary in the southeastern anatolian orogenic belt in east central turkey from baskil on the south to divrigi on the north broadly reflect shifting tectonic environments in an evolving collisional orogen a part of the extensive tethyan orogen late cretaceous 83 79 ma subduction related arc magmatism in the baskil arc was followed by extension that exhumed the metamorphic basement unroofed the obducted ophiolites and filled basins with maastrichtian to paleocene subaerial and submarine sedimentary rocks calc alkaline divrigi pluton 76 73 ma and alkaline igneous rocks hasancelebi and keban districts 76 74 ma accompanied post baskil arc extension in the early to middle eocene shallow and locally voluminous intrusions of intermediate composition copler kabatas bizmisen calti dedeyazi polat karamadazi and horoz localized mainly along major strike slip faults formed during closure of the neotethyan ocean these intrusions are dated between 50 and 44 ma peaking at 48 ma geochemical data from a suite of igneous rock samples across the transect reflect temporally based changes from arc type to late orogenic environments as demonstrated by late cretaceous rocks in the baskil area on the south and the more deeply eroded late cretaceous plutons in the divrigi area on the north divrigi these magmatic products were followed in the eocene by calc alkaline magmatism related to either incipient slab rupture or crustal scale faults that cut from northeast copler kabatas bizmisen calti and polat cavuslu to southwest karamadazi and horoz obliquely across the transect the multielement patterns for the late cretaceous magmatic rocks resemble the patterns for magmas generated in enriched source regions compared to primitive mantle and mid oceanic ridge basalt locally at divrigi hasancelebi and keban the geochemical characteristics are suggestive of the influx of low field strength elements into the mantle source regions from a subducted slab and an arc to postcollisional to late orogenic setting for their generation eocene magmatic rocks display similar geochemical characteristics regardless of the geographic setting and associated hydrothermal system their characteristics favor a subduction zone enrichment that was inherited either from an older event or from an older slab or from a mantle wedge contaminated by a contemporaneous subduction component 40ar 39ar and u pb geochronology on biotite zircon k feldspar hornblende and sericite from a suite of magmatic rocks and alteration zones defines three magmatic related metallogenic events in the southeastern anatolian orogenic belt between 78 and 44 ma the oldest metallogenic event between 78 to 74 ma is related to arc type calc alkaline magmatic rocks 83 79 ma intruded into the bitlis poturge and malatya keban metamorphics and overlying komurhan ispendere ophiolites of tauride platform uneconomic porphyry type cu au systems formed at topalkem baskil elazig and ispendere sisman malatya a second metallogenic event between 74 and 69 ma is contemporaneous with postcollisional exhumation and extension related magmatism during this event calc alkaline followed by alkaline magmatism 76 73 ma was accompanied by formation of iron oxide copper gold iocg systems at 74 to 73 ma at divrigi sivas alkaline magmatism at 76 to 74 ma is associated with iocg systems at hasancelebi malatya and porphyry cu mo and pb zn veins at keban elazig the youngest metallogenic event between 50 and 40 ma is represented by porphyry cu au deposits associated with calc alkaline intrusive complexes at copler and kabatas and fe skarns at karamadazi horoz dedeyazi and bizmisen calti

middle eocene paleomagnetic data from the eastern sakarya zone and the central pontides implications for the tectonic evolution of north central anatolia 1 a paleomagnetic investigation has been carried out on middle eocene volcanic rocks at 23 sites in the eastern sakarya zone and the central pontides of north central anatolia in order to better understand the regional tectonic evolution of the main zones of northeastern anatolia in the middle eocene the results constrain the tectonic evolution of the area when evaluated in conjunction with earlier published paleomagnetic directions from 92 localities small counterclockwise rotations in the range of r r 1 3 1 4 to r r 17 2 16 8 with respect to eurasia are observed in the central pontides on the northern side of the north anatolian fault naf clockwise rotations ranging between r r 8 5 15 1 and r r 29 7 12 0 are observed between the naf and the sungurlu fault sf in the eastern sakarya zone counterclockwise rotations of r r 18 9 12 4 to r r 42 2 6 9 are observed to the south of the sf our findings combined with previous data support the indentation model of kaymakci et al 2000 2003a 2003b which postulates the collision and northeast directed indentation of the kirsehir block into the sakarya zone this model which was developed to explain the evolution of the cankiri basin can also explain the variable magnitudes of paleomagnetically determined rotations thrust directions and the curvature of the north anatolian ophiolite belt

tectonic evolution of the troodos ophiolite within the tethyan framework a new tectonic model reconciles conflicting structural and geochemical evidence for the origin of the troodos ophiolite a well preserved remnant of neotethyan oceanic crust grabens and normal faults within the sheeted dike complex and the extrusive sequence of the troodos ophiolite resemble those of oceanic spreading centers diverse intrusive and tectonic contact relationships between the sheeted dike complex and the underlying plutonic sequence indicate multiple and episodic intrusion of magma and along and across strike variation in volcanic and tectonic activity during development of oceanic crust coupled with the existence of the arakapas transform fault to the south these structural and intrusive relationships suggest origin at an intersection between a spreading center and a transform fault the arclike chemistry of sheeted dikes and related extrusive rocks and the inferred highly depleted and hydrous nature of the mantle source of the late stage intrusive and extrusive rocks argue however for generation of part of the ophiolite within a subduction zone environment regional reconstructions suggest that the mesozoic neotethys may have evolved as a marginal basin both to the afro arabian continent and the paleotethyan ocean over an active or recently active south dipping subduction zone the troodos ophiolite and other eastern mediterranean ophiolites whose magma compositions were affected by the subducted paleotethyan slab may have formed along east west trending spreading centers separated by north south trending transform faults within this marginal basin a rapid change in relative plate motion in late cretaceous time between eurasia and afro arabia created a regional compressive regime that may have resulted in plate boundary reorganizations within the neotethyan realm and in initiation of north dipping subduction zone s beneath the troodos and other ophiolites in the region the apparent forearc setting of the troodos ophiolite is a consequence of this intraoceanic displacement after its formation and thus is unrelated to its generation

source mechanisms and faulting analysis of the aftershocks in the lake ercek area eastern anatolia turkey during the 2011 van event mw 7 1 implications for the regional stress field and ongoing deformation processes abstract in this study we analysed the source mechanisms and faulting pattern of the aftershocks in the lake ercek area eastern anatolia during the 2011 van event mw 7 1 the fault plane solutions of the aftershocks were used to derive a stress tensor acting around lake ercek the estimated seismological parameters focal mechanism solutions stress tensor and fault focal analyses were integrated with field surveys and high resolution seismic reflection data so as to better understand the main faulting patterns and deformational features which are the causatives of the observed geomorphological features within and around lake ercek the focal parameters of the 56 aftershocks with magnitude range 3 5 mw 5 5 were obtained using the regional broadband seismic data from the network of kandilli observatory and earthquake research institute koeri through the centroid moment tensor cmt inversion of locally observed broadband waves the implications for the lateral variation of the stress field in the lake area were based on information derived from integration of seismicity and stress tensor inversion results the major outcomes of our analyses were as follows a the maximum principal stress axis is close to horizontal and aligned in nnw sse direction the minimum compressional stress axis is close to vertical and aligned in an ene wsw direction the intermediate stress axis is close to horizontal and is parallel to the strike of the ruptured fault plane while the stress ratio is r 0 6 b the lake basin is mostly deformed by dip slip faults dips 45 60 in and along its margins where the various folds basement highs with eroded surfaces and several low angle normal faults are evident c the majority of the aftershocks have reverse thrust mechanism with some strike slip components in the lake ercek area n and s margins strike slip and normal faulting events are also evident e and w margins respectively d the normal and reverse mechanisms with some strike slip component are mostly confined in the upper crust 0 15 km compatible with ns striking normal and we striking reverse faults in the marginal sections of the lake e the we striking reverse faulting in the n and s margins seems to have the seismic potential to generate destructive earthquakes in the lake area f the tectonic implications of the regional stress field and ongoing deformation processes in the lake are defined and supported by field observations and seismic reflection data the result of these analyses reveals n s compression w e extension in the lake and also the collisional compressional regime taking place in a region of lakes van and ercek

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

a new tectonic scenario for the sanandaj sirjan zone iran abstract recent geochemical studies of volcanic rocks forming part of the ophiolites within the zagros and naien baft orogen indicate that most of them were developed as supra subduction ophiolites in intra oceanic island arc environments intra oceanic island arcs and ophiolites now forming the naien baft zone were emplaced southwestward onto the northeastern margin of the south sanandaj sirjan zone while those now in the high zagros were emplaced southwestward onto the northern margin of arabia thereafter subduction continued on opposite sides of the remnant oceans the floor of neo tethys ocean was subducted at a low angle beneath the entire sanandaj sirjan zone and the floor of the naien baft ocean was subducted beneath the central iranian micro continent the naien baft ocean extended into north west iran only temporarily this failed ocean arm between the urumieh dokhtar magmatic assemblage and the main zagros thrust was filled by thick upper triassic upper jurassic sediments the naien baft ocean finally closed in the paleocene and neo tethys closed in the early to middle eocene after arabia was sutured to iran the urumieh dokhtar magmatic assemblage recorded slab break off in the middle eocene

u pb and sm nd geochronology of the kizildag hatay turkey ophiolite implications for the timing and duration of suprasubduction zone type oceanic crust formation in the southern neotethys the kizildag hatay ophiolite in turkey represents remnants of the southern neotethyan ocean and is characterized by a complete ocean lithospheric section it formed in a fore arc setting above a n dipping intraoceanic subduction zone and represents the undeformed more northerly part of the same thrust sheet that also forms the baer bassit ophiolite to the south the ophiolite was emplaced southwards from the southerly neotethyan ocean in maastrichtian time u pb and sm nd dates are used to constrain the crystallization age and duration of magmatic activity of the kizildag ophiolite u pb dating yielded ages of 91 7 1 9 ma for a plagiogranite and 91 6 3 8 ma for a cumulate gabbro the cumulate gabbro also yielded a sm nd isochron age of 95 3 6 9 ma the measured ages suggest that the oceanic crust of the kizildag ophiolite formed in a maximum time period of 6 ma and that the plagiogranite may have formed later than the gabbroic section the u pb zircon ages from the kizildag ophiolite and the cooling age of a metamorphic sole beneath the baer bassit ophiolite are indistinguishable within the analytical uncertainties this indicates the presence of young and hot oceanic lithosphere at the time of intraoceanic subduction thrusting in the southern neotethys the u pb zircon ages from the kizildag the troodos and the semail ophiolites overlap within analytical uncertainties suggesting that these ophiolites are contemporaneous and genetically and tectonically related within the same late cretaceous southern neotethyan ocean

a numerical study of the effect of a mountain range on a landfalling tropical cyclone abstract a triply nested movable mesh model was used to study the effects of a mountain range on a landfalling tropical cyclone embedded in an easterly flow of 10 m s 1 the integration domain consisted of a 37 wide and 45 long channel with an innermost mesh resolution of 1 6 an idealized mountain range with maximum height of 958 meters was placed parallel to the shoreline the mountain range which spanned 19 in the north south direction and 5 in the east west direction was centered in the middle of the channel results obtained were compared with a previous landfall simulation performed without the effect of the mountain range included in particular comparison was made of the total storm rainfall maximum wind distribution and storm decay rate it was found that the storm filled much more rapidly in the simulation run with the mountain included the mountain range affected the decay rate through reduction in the supply of latent and kinetic energy into the storm circulation during as well

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

origin and interactions of fluids circulating over the amik basin hatay turkey and relationships with the hydrologic geologic and tectonic settings abstract we investigated the geochemical features of the fluids circulating over the amik basin se turkey syria border which is crossed by the northern extension of the dsf dead sea fault and represents the boundary area of three tectonic plates anatolian arabian and african plates we collected 34 water samples thermal and cold from natural springs and boreholes as well as 8 gas samples bubbling and gas seepage besides the gases dissolved in the sampled waters the results show that the dissolved gas phase is a mixture of shallow atmospheric and deep components either of mantle and crustal origin coherently the sampled waters are variable mixtures of shallow and deep ground waters the latter being characterised by higher salinity and longer residence times the deep groundwaters from boreholes deeper than 1000 m have a ch 4 dominated dissolved gas phase related to the presence of hydrocarbon reservoirs the very unique tectonic setting of the area includes the presence of an ophiolitic block outcropping in the westernmost area on the african plate as well as basalts located to the north and east on the arabic plate the diffuse presence of co 2 enriched gases although diluted by the huge groundwater circulation testifies a regional degassing activity fluids circulating over the ophiolitic block are marked by h 2 dominated gases with abiogenic methane and high ph waters the measured 3 he 4 he isotopic ratios display contributions from both crustal and mantle derived sources over both sides of the dsf although the serpentinization process is generally independent from mantle type contribution the recorded helium isotopic ratios highlight variable contents of mantle derived fluids due to the absence of recent volcanism over the western side of the basin african plate we argue that co 2 rich volatiles carrying mantle type helium and enriched in heavy carbon are degassed by deep rooted regional faults rather than from volcanic sources

the last glacial maximum climate over europe and western siberia a pmip comparison between models and data under the framework of the palaeoclimate modelling intercomparison project pmip 17 climate models 16 of which are atmospheric general circulation models have been run to simulate the climate of the last glacial maximum 21 000 years ago using the same set of boundary conditions parallel to these numerical experiments new consistent data bases have been developed on a continental scale the present work compares the range of the model responses to the large perturbation corresponding to the conditions of the last glacial maximum with consistently derived climate reconstructions from pollen records over europe and western siberia it accounts for the differences in the model results due to the models themselves and directly compares this error bar due to the models to the uncertainties in the climate reconstructions from the pollen records overall the last glacial maximum climate simulated by the models over western europe is warmer especially in winter and wetter than the one depicted by the reconstructions this is the region where the reconstructed increase in temperature precipitation and moisture index from the last glacial maximum to the present conditions is largest the same disagreement but of smaller amplitude is found over central europe and the eastern mediterranean basin while models and data are in broad agreement over western siberia the numerous modelling results allow a study of the link between the changes in atmospheric circulation and those in temperature and an interpretation of the discrepancies in precipitation in terms of those in temperature

curie point depth map of turkey summary a curie point isotherm map of the whole of turkey has been prepared from aeromagnetic data by means of a spectral analysis technique the most characteristic signature of this map is that the shallow depths generally correlated with the young volcanic rocks and the thinned crustal thicknesses in the west reveal geothermal fields and several hot springs the orogenic pontide belt of the black sea region in the north the western taurus belt in the south and some high plateaus in eastern turkey show that the deepest curie isotherm depths range between 20 and 29 km depth contour lines elongating in an almost e w direction are due to the overlapping percentage of adjacent data blocks of 50 per cent in the e w direction and to magnetic anomalies trending in the e w direction curie isotherm depths are in the range 6 to 10 km in the aegean region and are characterized by e w and ne sw trending graben structures as expected since the region has crustal thinning and many hot springs and geothermal fields these imply the existence of shallow heat sources that could be utilized for electricity heating of towns and cities greenhouse and health purposes

structure and deformation history of the bitlis suture near lake hazar southeastern turkey detailed mapping of the bitlis suture zone near lake hazar shows that it is composed of three tectonostratigraphic units which crop out as distinct north dipping thrust slices from south to north these are the puturge metamorphic complex the maden melange and the elazig igneous complex the puturge metamorphic complex consists of pre tertiary continental margin sediments metamorphosed to the greenschist facies during the campanian maastrichtian and deformed by four generations of structures these are in sequence 1 isoclinal folds and a transposition foliation 2 open folds crenulation cleavage and north dipping thrust faults 3 kink bands and 4 small displacement faults the maden melange represents middle eocene back arc basin sediments and volcanics metamorphosed to the greenschist facies and deformed by three generations of structures 1 a north dipping cleavage 2 kink bands and 3 small displacement faults the elazig igneous complex comprises an imbricated maastrichtian early eocene island arc and young marginal basin terrain thrust faults between units are north dipping listric and form a thin skinned system these features suggest the following deformational and tectonic history the puturge metamorphic complex was generated by isoclinal folding and metamorphism of sediments composing the arabian continental margin during campanian maastrichtian ophiolite obduction to the south the elazig arc developed on the deformed margin because of subsequent southward subduction of oceanic lithosphere the arc migrated to the north opening a back arc basin by the early eocene the back arc basin was filling with volcaniclastics of the maden melange and the elazig arc collided with a continent to the north during middle to late eocene convergence caused thrust stacking of the elazig maden and puturge complexes second generation deformation in the puturge complex and first generation deformation in the maden melange continued convergence with the arabian plate in the late miocene caused kink banding in the puturge and maden complexes since the late miocene this convergence has been accommodated by shortening and thickening along numerous internal faults

tectonic history of the hatay ophiolites south turkey and their relation with the dead sea rift abstract the kizildag ophiolite massif lies in the hatay region of s turkey some structural relationships in the area are examined and two geological sections through the ophiolite are presented a sequence of structural events dealing with the emplacement and post emplacement history is established the significance of the events is discussed and it is suggested that the post emplacement structural history was dominated by movements along the dead sea rift

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

control parameters for the influence of a mesoscale mountain range on cyclone track continuity and deflection abstract in this study prospective control parameters are identified for diagnosing the continuity and deflection of cyclone tracks across a mesoscale mountain range based on idealized simulations of a westward moving cyclone it was found that the cyclone track becomes a discontinuous continuous track and the cyclone experiences more less deflection with a combination of small large values of vmax nh u nh r ly u flx and vmax fr and large small value of h lx the symbols are defined as follows vmax the maximum tangential wind n the brunt vaisala frequency h the mountain height u the basic wind speed r the radius of vmax f the coriolis parameter and lx and ly the horizontal scales of the mountain in x and y directions respectively a conceptual model is proposed to explain track deflection and continuity for a westward moving cyclone encountering idealized topography representative of the central mountain range of taiwan with weak orographic blocking a cyclone crosses over the mount

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

the euphrates tigris karun river system provenance recycling and dispersal of quartz poor foreland basin sediments in arid climate we present a detailed sediment provenance study on the modern euphrates tigris karun fluvial system and mesopotamian foreland basin one of the cradles of humanity our rich petrographic and heavy mineral dataset integrated by sand geochemistry and u pb age spectra of detrital zircons highlights the several peculiarities of this large source to sink sediment routing system and widens the spectrum of compositions generally assumed as paradigmatic for orogenic settings comparison of classical static versus upgraded dynamic petrologic models enhances the power of provenance analysis and allows us to derive a more refined conceptual model of reference and to verify the limitations of the approach sand derived from the anatolia zagros orogen contains abundant lithic grains eroded from carbonates cherts mudrocks arc volcanics obducted ophiolites and ophiolitic melanges representing the exposed shallow structural level of the orogen with relative scarcity of quartz k feldspar and mica this quartz poor petrographic signature characterizing the undissected composite tectonic domain of the entire anatolia iranian plateau is markedly distinct from that of sand shed by more elevated and faster eroding collision orogens such as the himalaya arid climate in the region allows preservation of chemically unstable grains including carbonate rock fragments and locally even gypsum and reduces transport capacity of fluvial systems which dump most of their load in mesopotamian marshlands upstream of the arabian persian gulf allochemical carbonate factory quartz poor sediment from the anatolia zagros orogen mixes with quartz rich recycled sands from arabia along the western side of the foreland basin and is traced all along the gulf shores as far as the rub al khali sand sea up to 4000 km from euphrates headwaters

a magnetite rich cyprus type vms deposit in ortaklar a unique vms style in the tethyan metallogenic belt gaziantep turkey abstract the ortaklar vms deposit is hosted in the kocali complex consisting of basalts and deep sea pelagic sediments which formed by rifting and continental break up of the southern neotethyan in late triassic the basalts are of nmorb type without notable crustal contamination from the surface to depth the ortaklar deposit consists of a gossan zone a thick massive ore zone and a poorly developed stockwork zone primary mineralisation is characterised by distinctive facies including sulphide breccias proximal graded beds distal stockworks and chimney fragments ore mineral abundances decrease in the order of pyrite magnetite chalcopyrite and sphalerite two distinct phases of mineralisation massive magnetite and massive sulphide are present in the ortaklar deposit textural evidence e g magnetite replacing sulphides and the spatial relationships with the host rocks indicate that magnetite and sulphide minerals were generated in different stages the transition from sulphide to magnetite mineralisation is interpreted to relate to variation in h2s content of ore fluids the 1st stage massive sulphide ore might have formed by early hydrothermal fluids rich in fe and h2s the 2nd stage massive magnetite might have formed by later neutral hydrothermal fluids rich in fe but poor in h2s replacing the pre existing sulphide ore the alteration patterns mineral paragenesis lithological features massive ore stockwork ore gossan of the ortaklar deposit together with its trace elements cu pb zn au ag and ree signatures are all consistent with a cyprus type vms system the 34s values in pyrite and chalcopyrite samples range from 2 6 to 5 7 indicating that the hydrothermal fluids were associated with sub seafloor igneous activity typical of cyprus type vms deposits however magnetite formed later than sulphide minerals in the ortaklar deposit contrasting with typical cyprus type vms deposits where magnetite generally occurs in lower sections consequently although the ortaklar deposit generally conforms to cyprus type deposits it is distinguished from them by its late stage and high magnetite concentration thus the ortaklar deposit is thought to be an exceptional and perhaps unique cyprus type vms deposit

upper cretaceous plate rupture and development of leaky transcurrent fault ophiolites in southeast turkey abstract field observations in the thrust fault belt in southeastern turkey reveal two contradictory relationships regarding the existence of the turkish microplate and the southern tethys jurassic and early cretaceous sediments on the platforms of the turkish and arabian plates can be correlated this weakens the hypothesis that the turkish plate was separated from africa in the triassic on the other hand stratigraphic relationships on slivers of continental crust between ophiolite strips do not allow the ophiolites north and south of such continental blocks to be linked this necessitates postulating the previous existence of distinct oceanic basins between the continental slivers the ophiolites in southeastern turkey are of upper cretaceous age the separation of the turkish microplate and the generation of southern tethys in southeastern turkey did not take place in triassic times but in the late cretaceous plate rupture was probably caused by a major change in plate motions 80 m y ago the turkish plate was completely sheared off the northern edge of africa by northeasterly trending transcurrent faults through southeastern turkey mantle leakage along such transcurrent faults must have generated the ophiolites of the thrust fault belt of south eastern turkey in narrow ocean basins between ribbons of continental crust

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