kinematic reconstructions and magmatic evolution illuminating crustal and mantle dynamics of the eastern mediterranean region since the late cretaceous the relationship between subduction dynamics and crustal deformation in the mediterranean region has been recently studied using three dimensional 3d numerical models such models require however a detailed information concerning the past geological evolution we use stratigraphic petrologic metamorphic structural paleomagnetic and magmatic data to build new kinematic reconstructions of the eastern mediterranean region since the late cretaceous using the principle of non rigid domains the motions of the 56 deforming domains defined in this work are calculated based on published paleomagnetic rotations the directions and amounts of displacement on crustal scale shear zones and the burial and exhumation histories of the main metamorphic units extracted from these reconstructions paleotectonic maps and lithospheric scale cross sections illustrate that the present day subduction zone has been continuously retreating southward since the late cretaceous and has accreted several small continental domains in the process we find evidence for two back arc related extensional events 1 slow extension along the balkans and the pontides in the late cretaceous while the trench was long and linear and 2 faster extension in the rhodope aegean west anatolian region since the eocene oligocene rapid rotation of the hellenides between 15 and 8 ma probably indicates a slab tearing event below western anatolia that could have further accelerated this extensional kinematics spatial distribution and the geochemical signature of magmatic centers integrated in these reconstructions allow us to trace mantle related processes revealing the deep dynamics that controls both the magma genesis and the crustal deformation

significance of ferrodioritic liquids in magma mixing processes a general model to explain the various igneous associations found in mixed magma intrusives and extrusives belonging to high level volcanic centres is presented this model is based on detailed mapping in the british tertiary volcanic centre on skye which suggests that basic and acid magmas were continually available throughout its development new major and trace element data from these rocks indicate that they were co genetic and that the basic magmas which combined with acid magmas to produce hybrid magmas were ferrodioritic in composition and not basaltic as had previously been thought

melange genesis and ophiolite emplacement related to subduction of the northern margin of the tauride anatolide continent central and western turkey the tauride anatolide continent stretching for c 900 km across western and central turkey is one of the world s best example of a subducted exhumed passive margin within a collisional orogen twelve widely separated areas were studied and correlated to develop a new plate tectonic model a metamorphosed rifted continental margin of triassic lower cretaceous age tauride anatolide platform is overlain by upper cretaceous cenomanian lower maastrichtian pelagic sediments and then by both tectonic melange subduction complexes and sedimentary melange foredeep gravity complexes the melanges are overthrust by unmetamorphosed ophiolitic rocks commonly peridotites with swarms of diabase gabbro dykes and are underlain by metamorphic soles new geochemical evidence from basaltic blocks in the melange indicates predominantly subduction influenced within plate and mid ocean ridge type settings the dykes cutting the ophiolites were probably intruded during early stage intra oceanic arc genesis the metamorphosed continental margin melanges and ophiolites in the north anatolides are correlated with unmetamorphosed equivalents in the taurides further south e g beysehir and lycian nappes oceanic crust of triassic late cretaceous age formed between the gondwana related tauride anatolide continent in the south and the eurasia related sakarya microcontinent in the north following late triassic early cretaceous passive margin subsidence the continental margin was covered by cenomanian turonian pelagic carbonates c 98 90 ma ophiolites formed in an intra oceanic subduction zone setting in response to northward subduction probably within a two stranded ocean with the inner tauride ocean in the se and the izmir ankara erzincan ocean in the north nw metamorphic soles relate to intra oceanic subduction c 95 90 ma oceanic sedimentary igneous rocks accreted to the advancing supra subduction oceanic slab the tauride anatolide continental margin then underwent diachronous collision with the trench c 85 ma deeply subducted and metamorphosed at hp lt c 80 ma accretionary ophiolitic and exhumed hp lt rocks were gravity reworked into a southward migrating flexural foredeep and progressively overridden c 70 63 ma slices of the upper part of the platform and its margin detached and were thrust southwards as the tauride lycian and beysehir nappes together with regional scale ophiolites the continental margin and melange were simultaneously exhumed during maastrichtian early paleocene 70 63 ma and transgressed by shallow water sediments beginning in the late maastrichtian in the east c 64 ma and the mid late paleocene c 60 ma further west remnant oceanic crust was consumed during early cenozoic time followed by mid eocene 45 40 ma diachronous continental collision and a second phase of regional deformation rather than being progressive there were two stages of collision first upper cretaceous ophiolite emplacement driven by continental margin subduction trench collision and secondly eocene collision of the tauride and sakarya eurasian continents

petrogenesis of post collisional a type granitoids from the urumieh dokhtar magmatic assemblage southwestern kerman iran constraints on the arabian eurasian continental collision abstract three plutons deh siahan bande bagh and baghe khoshk sharghi collectively referred to as the dbb hereafter in southwestern kerman in the southeastern part of the urumieh dokhtar magmatic assemblage udma of the zagros orogenic belt differ from the typical calc alkaline metaluminous i type intrusions of the region the dbb intrusions have a distinct lithological assemblage varying from diorite through monzogranite and monzonite to alkali feldspar syenite and alkali granite the dbb granitoids are metaluminous to slightly peraluminous alkaline to shoshonitic in composition and have high total alkali contents with k2o na2o high feot mgo values and low cao and mgo contents they are enriched in some liles such as rb and th and hfses such as zr y and rees except eu and depleted in sr and ba relative to primordial mantle and have low concentrations of transitional metals these features along with various geochemical discriminant diagrams suggest that the dbb granitoids are post collisional a type granitoids which had not been recognized previously in the udma the chondrite normalized ree patterns of the dbb granitoids show slightly enriched light rees la sm n 2 26 4 13 negative eu anomalies eu eu n 0 19 0 74 and flat heavy ree patterns gd yb n 0 80 1 87 the negative eu anomaly indicates an important role for plagioclase and or k feldspar during fractional crystallization whole rock rb sr isotope analysis yields an isochron age of 33 1 ma with an initial 87sr 86sr value of 0 7049 0 0001 whole rock sm nd isotope analysis gives endt values from 2 56 to 3 62 at 33 ma the positive endt and low isr values of the dbb granitoids together with their tdm of 0 6 0 7 ga suggest their formation from partial melting of a lithospheric mantle source modified by fluids or melts from earlier subduction processes melting of lithospheric mantle occurred via a dehydration melting process at pressures below the garnet stability field as a consequence of lithospheric mantle delamination or break off of a subducted slab and melting of the lithospheric mantle by upwelling of hot asthenosphere on the basis of rb sr age dating and the post collisional geochemical signatures of the dbb granitoids along with extensive pre collisional volcanic eruptions in middle eocene we suggest late eocene for the time of collision between the arabian and central iranian plates this also implies that the calc alkaline i type intrusions in the southwestern kerman and in other parts of the udma may have formed in a post collisional context

plutonic rock types series discrimination of various granitoid series and related rocks abstract the streckeisen qap diagram discriminates four characteristic type series among the large variety of granitoids associated in intrusions three of them integrate varied compositions from basic to acid terms 1 the calcalkaline series with its low k or trondhiemite medium k or granodioritic high k or monzonitic variants 2 the alkaline series with its characteristic syenitic members 3 the tholeiitic series deprived of k feldspars the fourth 4 corresponds to mobilizates associated with migmatites of varied composition but always quartz rich the generalization in the qapf system allowing the plotting of undersaturated alkaline series provides an excellent visual display of the major associations and trends for the plutonic rocks

the continental plates are getting thicker petrologists and seismologists now agree that the old cores of the continents have deep roots extending well below the thickest ocean plates

mortality in england during the 1783 4 laki craters eruption 1783 4 has been recognised as a mortality crisis year in the population history of england this demographic incident coincides with the laki craters eruption iceland which began in june 1783 and fumigated many parts of europe with volcanic gases and particles many reports and proxy climate records implicate the volcanic cloud in meteorological anomalies including notably hot 1783 summer conditions in england and a severe subsequent winter we present here a detailed analysis of the geographical and temporal trends in english mortality data and interpret them in the light of the climatological records and observations of the pollutant cloud we show that there were two distinct crisis periods in august september 1783 and january february 1784 which together accounted for 20 000 extra deaths in both cases the east of england was the worst affected region possible causes for the two crisis periods are considered and we conclude that the timing and magnitude of the winter mortality peak can be explained by the severe cold of january 1784 the late summer mortality followed 1 2 months after the very hot july of 1783 and may also have been related to the weather with the time lag reflecting the relatively slow spread of enteric disease or the contraction of malaria however it is hard to explain the entire late summer anomaly by these high temperature causes we therefore consider that fine acid aerosol and or gases in the volcanic haze may also have contributed to the unusual august september mortality given that complex radiative and dynamical effects of the volcanic cloud are implicated in the climatic anomalies in 1783 4 it is likely that the laki craters eruption did play a role in the english mortality crises of the same period

collision tectonics in the nw himalayas west himalayan tectonics involve the collision of microplates between the indian and asian plates the kohistan complex consists largely of tightly folded basic volcanics and sediments generated as late jurassic to late cretaceous island arcs these were intruded by post folding mid cretaceous eocene plutonics produced from continued subduction of the indian plate after closure of a suture between kohistan and the karakorum the himalayan structures show major thrust sheets and the kohistan arc is essentially a crustal pop up with southward upright and northward verging structures developed above a thick ductile decoupling zone the indus suture which can be traced for 100 km beneath kohistan on large reentrants this pop up formed by a two stage process closure of the northern suture followed by closure of the southern indus suture granitic rocks of the kohis tan ladakh batholith dated at 100 40 ma post date most of the structures related to the northern suture but were deformed and carried southwards on shear structures related to the indus suture postcollisional deformation carried this kohistan complex on deep decoupling zones over the indian plate on a series of imbricated gneiss sheets the thrusts climbing up section in the movement direction so that in the far s some override their own molasse debris folds above these deep decoupling zones deformed their overlying thrust sheets into large antiforms i e the nanga parbat and hazara syntaxes the nanga parbat syntaxis probably formed due to a shear couple near a branch line where one of the main himalayan thrusts joined the indus suture beneath kohistan crustal delamination to produce the imbricated gneiss sheets could not account for all the displacement of india into asia suggested by palaeomagnetic data there must also have been lateral displacement as demonstrated by the large oblique slip shear zone in the hunza valley n of kohistan

tertiary evolution of the sivas basin central turkey abstract the sivas basin is one of several basins in turkey formed during closure of the northern branch of neotethys in early tertiary times cretaceous ophiolitic fragments and eocene platform carbonates and volcaniclastics transported northwards into the basin as olistoliths and grain flow aprons were incorporated into autochthonous eocene turbidites and bioclastic limestones the sequence as a whole was thrust northwards in late eocene times a southward sloping terrestial foreland basin related to northward directed thrusting developed during oligocene times a piggy back basin developed on top of this thrust system during the late oligocene the eocene thrusts were reactivated probably resulting in northward propagation of thrusts in the subsurface in early and mid miocene times the basin was floored by a thrust sheet which had been cut by n s trending tear faults or oblique culminations as a result of non uniform thrust advance in pre miocene times these n s faults were subsequently reactivated as extensional faults radial to the thrust front during early to mid miocene alluvial and shallow marine sedimentation later strike slip displacement along the n s faults was associated with the development of the northern boundary fault of the sivas basin in late miocene times which is regarded as a left lateral transpressive fault related to the north anatolian fault zone

boundary lines within petrologic diagrams which use oxides of major and minor elements use of some petrologic diagrams applied to analyses of volcanic rocks is unnecessarily difficult due to lack of data for construction of discriminant lines between rock series coordinates are provided for sufficient points to enable accurate plotting of the boundary lines within seven diagrams viz 1 tas total alkalies na2o k2o vs sio2 2 k2o vs sio2 3 afm 4 jensen 5 ktp k2o tio2 p2o5 6 fms feo mgo vs sio2 and 7 taktip k2o na2o k2o vs tio2p2o5 different versions of these boundaries are collated to indicate their variable position and it is demonstrated that inter laboratory analytical precision suffices to account for almost all of their spread on the tas and k2o vs sio2 diagrams

satellite detection long range transport and air quality impacts of volcanic sulfur dioxide from the 2014 2015 flood lava eruption at barðarbunga iceland the 2014 2015 bar arbunga vei ivotn fissure eruption at holuhraun produced about 1 5 km3 of lava making it the largest eruption in iceland in more than 200 years over the course of the eruption daily volcanic sulfur dioxide so2 emissions exceeded daily so2 emissions from all anthropogenic sources in europe in 2010 by at least a factor of 3 we present surface air quality observations from across northern europe together with satellite remote sensing data and model simulations of volcanic so2 for september 2014 we show that volcanic so2 was transported in the lowermost troposphere over long distances and detected by air quality monitoring stations up to 2750 km away from the source using retrievals from the ozone monitoring instrument omi and the infrared atmospheric sounding interferometer iasi we calculate an average daily so2 mass burden of 99 49 kilotons kt of so2 from omi and 61 18 kt of so2 from iasi for september 2014 this volcanic burden is at least a factor of 2 greater than the average so2 mass burden between 2007 and 2009 due to anthropogenic emissions from the whole of europe combining the observational data with model simulations using the united kingdom met office s numerical atmospheric dispersion modelling environment model we are able to constrain so2 emission rates to up to 120 kilotons per day kt d during early september 2014 followed by a decrease to 20 60 kt d between 6 and 22 september 2014 followed by a renewed increase to 60 120 kt d until the end of september 2014 based on these fluxes we estimate that the eruption emitted a total of 2 0 0 6 tg of so2 during september 2014 in good agreement with ground based remote sensing and petrological estimates although satellite derived and model simulated vertical column densities of so2 agree well the model simulations are biased low by up to a factor of 8 when compared to surface observations of volcanic so2 on 6 7 september 2014 in ireland these biases are mainly due to relatively small horizontal and vertical positional errors in the simulations of the volcanic plume occurring over transport distances of thousands of kilometers although the volcanic air pollution episodes were transient and lava dominated volcanic eruptions are sporadic events the observations suggest that i during an eruption volcanic so2 measurements should be assimilated for near real time air quality forecasting and ii existing air quality monitoring networks should be retained or extended to monitor so2 and other volcanic pollutants

origin of the xiaohekou skarn copper deposit and related granitoids in the zha shan ore cluster area south qinling china abstract the xiaohekou copper deposit is one of the few typical skarn type commercial deposits in the zha shan ore cluster area in the eastern part of south qinling the ore related granitoids in the xiaohekou mining district include a number of small plutons of granodiorite porphyry and granite porphyry as well as numerous dykes they are characterized by relatively low sio2 65 9 73 3 wt and mgo 0 26 1 72 wt contents variable mg 29 4 64 0 values high k2o 3 11 5 75 wt content and negligible eu 1 00 1 15 values the samples also exhibit depletion in cr ni nb ta and ti content and high sr y 46 6 64 7 and la yb 17 0 25 0 ratios these features are similar to those of high k calc alkaline adakite like magma formed by partial melting of thickened lower crust in continental collision zones or intracontinental settings the majority of the samples have tdm2 hf of 1 5 1 2 ga corresponding to weakly negative ehf t values 4 75 to 0 13 typical of crustal material but more than one quarter have tdm1 hf of 0 80 0 71 ga corresponding to positive ehf t values of 0 07 to 2 45 indicating that the granitoids resulted from partial melting of mesoproterozoic lower crustal rocks with significant input from enriched lithospheric mantle derived magmas zircons from the xiaohekou granitoids have fmq values concentrated around 0 62 to 5 54 most of which show the magma fo2 of fmq to hm in accordance with the widespread occurrence of magnetite hematite and specularite in the xiaohekou skarn system which is an indicator of relatively high fo2 for a magmatic hydrothermal system the granitoids exhibit similar or even higher ce4 ce3 average of 452 and eu eu average of 0 72 values in comparison with those of fertile cu deposits worldwide indicating that the xiaohekou granitoids may possess the potential to form a large magmatic hydrothermal cu deposit zircons of the granitoids show obvious positive correlations between oxidation indices ce and eu anomalies ce4 ce3 ratios and fmq values and ehf t values implying the involvement of an oxidized mantle component which might have caused the fo2 elevation and played an important role in the formation of cu deposits the zircon u pb ages 141 3 1 3 and 138 1 2 0 ma of the xiaohekou ore related granitoids obtained in this study are similar to the zircon u pb and molybdenite re os ages yielded from porphyry mo mineralization at the chigou and lengshuigou deposits in the zha shan ore district indicating that they are possibly part of a single tectonic magmatic and metallogenic event in the yanshan orogeny the ore related granitoids in the xiaohekou area were formed in a post collisional compression extension transition regime during the early cretaceous qinling intracontinental orogeny the orogeny can be attributed to the far field effect of a switch from pre mesozoic tethyan tectonics to late mesozoic pacific tectonics this triggered a stress field transition from n s to e w trending and from intracontinental subduction thickening to large scale lithospheric delamination and thinning

seismic structure crustal architecture and tectonic evolution of the anatolian african plate boundary and the cenozoic orogenic belts in the eastern mediterranean region the modern anatolian african plate boundary is represented by a north dipping subduction zone that has been part of a broad domain of regional convergence between eurasia and afro arabia since the latest mesozoic a series of collisions between gondwana derived ribbon continents and trench roll back systems in the tethyan realm produced nearly east west trending subparallel mountain belts with high elevation and thick orogenic crust in this region ophiolite emplacement terrane stacking high p and barrovian metamorphism and crustal thickening occurred during the accretion of these microcontinents into the upper plates of tethyan subduction roll back systems during the late cretaceous early eocene continued convergence and oceanic lithospheric subduction within the tethyan realm were punctuated by slab breakoff events following the microcontinental accretion episodes slab breakoff resulted in asthenospheric upwelling and partial melting which facilitated post collisional magmatism along and across the suture zones resumed subduction and slab roll back induced upper plate extension triggered a tectonic collapse of the thermally weakened orogenic crust in anatolia in the late oligocene miocene this extensional phase resulted in exhumation of high p rocks and mediumto lower crustal material leading to the formation of metamorphic core complexes in the hinterland of the young collision zones the geochemical character of the attendant magmatism has progressed from initial shoshonitic and high k calc alkaline to calc alkaline and alkaline affinities through time as more asthenosphere derived melts found their way to the surface with insignificant degrees of crustal contamination the occurrence of discrete high velocity bodies in the mantle beneath anatolia as deduced from lithospheric seismic velocity data supports our tethyan slab breakoff interpretations pn velocity and sn attenuation tomography models indicate that the uppermost mantle is anomalously hot and thin consistent with the existence of a shallow asthenosphere beneath the collapsing anatolian orogenic belts and widespread volcanism in this region the sharp north pointing cusp isparta angle between the hellenic and cyprus trenches along the modern anatolian african plate boundary corresponds to a subductiontransform edge propagator step fault which is an artifact of a slab tear within the downgoing african lithosphere

re os molybdenite ages of granitoid hosted mo cu occurrences from central anatolia turkey abstract the central anatolian crystalline complex cacc where many granitoids are emplaced and related ore occurrences deposits occur is tectonically located in the alpine himalayan belt the cacc hosts numerous ore occurrences deposits cu mo fe pb and zn that are spatially associated with granitoids the calc alkaline karacaali baliseyh and basnayayla granitoids that form the northern granitoid belt of the cacc host important mo cu occurrences in this paper we document re os isotopic age data in molybdenites to determine the timing of the granitoid hosted mineralizations in the cacc the re content of molybdenite in the basnayayla is significantly higher 108 9 148 5 ppm than molybdenites from the karacaali 16 3 74 8 ppm and baliseyh 4 2 ppm two molybdenite samples from karacaali and two samples from basnayayla occurrences give re os ages ranging from 73 8 0 4 to 76 2 0 4 ma and 77 1 0 4 to 78 0 0 4 ma respectively furthermore one molybdenite sample from baliseyh gives a 73 6 0 4 ma re os age these ages are consistent with those of post collisional granitoids and indicate close relationship between mineralization events and granitic magma differentiation crystallization processes the new re os age data obtained from this study show that mineralization events developed earlier 78 77 ma in the east basnayayla as compared with the west 76 73 ma karacaali and basliseyh of central anatolia moreover one molybdenite sample from karacaali gives 76 2 ma which is very close to the basnayala ages 78 and 77 1 ma according to these data one possible explanation is that older molybdenite ages in karacaali and basnayayla probably represent the mineralization period related to crystallization differentiation processes on the other hand the younger molybdenite age 73 8 ma in the karacaali may represent prolongation of the life of magmatic hydrothermal processes cycles and or the remobilization of molybdenum within the solidified granitic system by the intrusion of the basic magma

trace element geochemistry of high alumina basalt andesite dacite rhyodacite lavas of the main volcanic series of santorini volcano greece trace element systematics throughout the cal calkaline high alumina basalt basaltic andesite andesite dacite rhyodacite lavas and dyke rocks of the main volcanic series of santorini volcano greece are consistent with the crystal fractionation of observed phenocryst phases from a parental basaltic magma as the dominant mechanism involved in generating the range of magmatic compositions marked inflection points in several variation trends correspond to changes in phenocryst mineralogy and divide the main series into two distinct crystallisation intervals an early basalt to andesite stage characterised by calcic plagioclase augite olivine separation and a later andesite to rhyodacite stage generated by plagioclase augite hypersthene magnetite apatite crystallisation percent solidification values derived from ratios of highly incompatible trace elements agree with previous values derived from major element data using addition subtraction diagrams and indicate that basaltic andesites represent 47 69 andesites 70 76 dacites ca 80 and rhyodacite ca 84 crystallisation of the initial basalt magma least squares major element mixing calculations also confirm that crystal fractionation of the least fractionated basalts could generate derivative main series lavas though the details of the least squares solutions differ significantly from those derived from highly incompatible element and addition subtraction techniques main series basalts may result from partial melting of the mantle asthenosphere wedge followed by limited olivine pyroxene cr spinel crystallisation on ascent through the sub aegean mantle and may fractionate to more evolved compositions at pressures close to the base of the aegean crust residual andesitic to rhyodacite magmas may stagnate within the upper regions of the sialic aegean crust and form relatively high level magma chambers beneath the southern volcanic centres of santorini the eruption of large volumes of basic lavas and silicic pyroclastics from santorini may have a volcanological rather than petrological explanation

illness and elevated human mortality in europe coincident with the laki fissure eruption grattan j durand m taylor s illness and elevated human mortality in europe coincident with the laki fissure eruption in volcanic degassing geological society special publication 213 oppenheimer c pyle d m and barclay j eds geological society london special publications 410 414 2003

balloon borne measurement of the aerosol size distribution from an icelandic flood basalt eruption we present in situ balloon borne measurements of aerosols in a volcanic plume made during the holuhraun eruption iceland in january 2015 the balloon flight intercepted a young plume at 8 km distance downwind from the crater where the plume is 15 min of age the balloon carried a novel miniature optical particle counter loac light optical aerosol counter which measures particle number concentration and size distribution in the plume alongside a meteorological payload we discuss the possibility of calculating particle flux by combining loac data with measurements of sulfur dioxide flux by ground based uv spectrometer doas the balloon passed through the plume at altitude range of 2 0 3 1 km above sea level a s l the plume top height was determined as 2 7 3 1 km a s l which is in good agreement with data from infrared atmospheric sounding interferometer iasi satellite two distinct plume layers were detected a non condensed lower layer 300 m thickness and a condensed upper layer 800 m thickness the lower layer was characterized by a lognormal size distribution of fine particles 0 2 m diameter and a secondary coarser mode 2 3 m diameter with a total particle number concentration of around 100 cm 3 in the 0 2 100 m detection range the upper layer was dominated by particle centered on 20 m in diameter as well as containing a finer mode 2 m diameter the total particle number concentration in the upper plume layer was an order of magnitude higher than in the lower layer we demonstrate that intercepting a volcanic plume with a meteorological balloon carrying loac is an efficient method to characterize volcanic aerosol properties during future volcanic eruptions balloon borne measurements could be carried out easily and rapidly over a large spatial area in order to better characterize the evolution of the particle size distribution and particle number concentrations in a volcanic plume

hybridization of mafic microgranular enclaves mineral and whole rock chemistry evidence from the karamadazi granitoid central turkey on the eastern tauride belt the cretaceous calc alkaline karamadazi granitoid consists of quartz diorite containing mafic microgranular enclaves mme and leucocratic granite the quartz diorite consists of plagioclase an8 65 hornblende biotite k feldspar quartz epidote and titanite subrounded mme in the quartz diorite are holocrystalline fine grained quartz diorite to diorite in composition and display a similar mineral assemblage to their host large crystals in mme and quartz diorite show various disequilibrium microstructures indicative of hybridization plagioclase crystals exhibit inverse normal and oscillatory zoning with maximum core to rim an content increase up to 38 in the enclave and 40 in the quartz diorite both hornblende and augite exhibit normal and reverse zoning even in the same sample the new field textural mineral compositional and geochemical evidence leads to the conclusion that mme could have formed through injection of successive pulses of basic magma into upward mobile magma chambers containing cooler partially crystalline quartz diorite magma the quartz diorites show similarity to high al ttg tonalites trondhjemites granodiorites with their high na2o sr lree and low mg cr hree contents and are suggested to be produced by extensive interaction between the crustal and mantle derived melts through mixing at depth in contrast leucogranites have geochemical characteristics distinct from the quartz diorites and mme and are probably not involved in mme genesis

inverted metamorphic zonation and variscan thrust tectonics in the rouergue area massif central france p t t record from mineral to regional scale

petrogenetic interpretation of granitoid rock series using multicationic parameters abstract granitoid rock compositions from a range of tectonic environments are plotted on a multicationic diagram devised by de la roche and his coworkers this shows that there is a systematic change through an orogenic cycle which leads progressively to the ultimate development of alkaline magmas possible source materials and mechanisms of magma generation are considered from analysis of mineral compositional vectors these suggest that most granitoid series result from a two stage process first fractional crystallisation of clinopyroxene olivine and calcic plagioclase from a basic source with tholeiitic affinities produces a magma of intermediate composition this magma then undergoes periodic mixing with a felsic magma followed by in situ fractionation to generate individual intrusions within granitoid series

comment on 207pb 206pb single zircon evaporation ages of some granitoid rocks reveal continent oceanic island arc collision during the cretaceous geodynamic evolution of the central anatolian crust turkey boztug d tichomirowa m bombach k 2007 jaes 31 71 86 abstract a continent oceanic island arc collision model was proposed as a new geodynamic scenario for the evolution of the cretaceous central anatolian granitoids in the central anatolian crystalline complex cacc by boztug et al 2007b boztug d tichomirowa m bombach k 2007b 207pb 206pb single zircon evaporation ages of some granitoid rocks reveal continent oceanic island arc collision during the cretaceous geodynamic evolution of the central anatolian crust turkey journal of asian earth sciences 31 71 86 the key aspects of this model include an intra oceanic subduction in the neotethyan izmir ankara ocean formation of an island arc and its subsequent collision with the northern margin of the tauride anatolide platform the identical scenario was initially proposed by goncuoglu et al 1992 goncuoglu m c erler a toprak v yaliniz k olgun e rojay b 1992 geology of the western central anatolian massif part ii central areas tpao report no 3155 76 p moreover the weighted mean values of the reported 207pb 206pb single zircon evaporation ages by boztug et al 2007b boztug d tichomirowa m bombach k 2007b 207pb 206pb single zircon evaporation ages of some granitoid rocks reveal continent oceanic island arc collision during the cretaceous geodynamic evolution of the central anatolian crust turkey journal of asian earth sciences 31 71 86 from a type granitoids in the cacc seem to be miscalculated and contrast with the field data

evaluation of potentially toxic element contents and pb isotopic compositions in ankara stream sediments within an urban catchment in central turkey this study aimed to interpret the spatial distribution enrichment factor ef and geo accumulation of potentially toxic elements in the bed sediments asbs and pleistocene aged overbank sediments asos of the ankara stream in turkey the potential toxic pollution of the investigated potentially toxic elements was defined by evaluating the ef geo accumulation index i geo and pb anthropogenic contribution the distributions of as ni and co in the analyzed sediments were uniform in the asbs and asos along the length of the stream the ef and i geo values indicated that asbs and asos were significantly polluted by as and ni and moderately polluted by co zn and cu asbs was locally strongly polluted by pb and cd pb anthropogenic contribution was estimated at an average of 100 in the asbs and asos the potentially toxic element levels and distribution patterns revealed that industrial activities gasoline combustion vehicular emission phosphate fertilizers and natural sources were probable causes of metal pollution in ankara stream sediments these potentially toxic elements were transported by atmospheric conditions and stream water the potentially toxic elements in ankara stream increased with each passing day and were important in evaluating the potential toxicity risks to living organisms thus suitable measures should be taken to ensure appropriate treatment of wastewater before toxic residues are disposed into the nearby stream chimney filter treatment plants and appropriate technology should be used in the organized industrial zone to prevent atmospheric pollution

hydrothermal breccia related cumoau mineralization in late precambrian granites western cape province south africa abstract hydrothermal breccia bodies with cu mo au mineralization are present in a leucogranite related to the precambrian cape granite suite the host rock is typical of anorogenic a type associations ranging in composition from quartz syenite to alkaligranite the quartz syenites contain na ca amphiboles and range from amphibole to biotite amphibole and leucoratic syenites a major hydrothermal event affecting the alkaligranite took place at 450 c co 2 overpressure caused the first brecciation event the breccias are present in the alkaligranite and on the contact of alkaligranite and quartz syenites at least three stages of brecciation are recognizable the latter stage typical of low temperature epithermal conditions and siderite enrichment cu mineralization is restricted mainly to the breccias and highest values are obtained in sheeting zones bordering the intensely brecciated areas au and mo mineralization is erratic and although the breccias are generally enriched in these two elements high values are typically found in alkaligranite not affected by brecciation

oxygen and sulfur isotope geochemistry revealing a significant crustal signature in the genesis of the post collisional granitoids in central anatolia turkey abstract late cretaceous granitoid rocks from central anatolia comprise s i a type plutons derived from the collisional stages of the neo tethyan convergence system in central turkey these granitoids intrude the tectonic imbrication zone consisting of blocks of supra subduction zone type ssz type central anatolian ophiolite and crustal metasediments which are present in the izmir ankara erzincan suture zone the plutons are overlain by late palaeocene early eocene or younger detrital sediments granitoid formation is thought to be related to magma generation processes occurring in a post collisional lithospheric detachment related geodynamic setting that resulted from slab break off or lithospheric delamination whole rock s and quartz feldspar o isotope data from these plutons yields a broad range of values and both parameters indicate a nearly exclusively supracrustal origin for the s type granites as well as a significant crustal contribution in the genesis of the hybrid i type and a type granitoids the more mafic i type and a type granitoid rocks of any given suite have lower s and o values indicative of their larger degree of mantle component the combined stable isotope geochemical compositions when coupled with major trace and ree geochemistry and regional geology provide evidence that the significant crustal contribution originated from a metasomatized mantle layer which was affected by earlier ssz derived fluids and then accreted into the subcontinental lithosphere as collision occurred the partial melting of such a metasomatized mantle layer in a post collisional extensional geodynamic setting supplied either by the slab break off or lithospheric delamination mechanisms provided the significant crustal signature in the hybrid magmas of the late cretaceous i type and a type granitoids in central anatolia turkey

core complex development in central anatolia turkey tectonic models for the central anatolian segment of the alpine himalayan orogen have not considered this region as part of the aegean extensional province we have found evidence however for oligocene miocene extension and exhumation of midcrustal rocks in a metamorphic dome nigde massif that is structurally and petrologically similar to miocene core complexes 500 km to the west strong correspondence in the timing and kinematic development of the menderes western turkey and nigde core complexes suggests that extensional tectonics and exhumation of mid to lower crustal rocks affected much of the eastern mediterranean region in the nigde massif supracrustal rocks were buried to depths of 16 20 km at high temperatures 700 c during contraction associated with closure of neo tethyan seaways in late mesozoic early cenozoic time following cooling and decompression to 600 c and 10 km metasedimentary rocks underwent a second heating event at low pressures during miocene magmatism that postdated much of the unroofing of the massif development of the nigde core complex was related to exhumation of thickened and thermally weakened continental crust in the upper plate of a north dipping subduction zone the partial subduction of the tauride carbonate platform in the eocene resulted in choking of the subduction zone followed by isostatic rebound and exhumation of the buoyant platform this in turn caused a rapid emergence of the upper plate resulting in erosion of upper crustal rocks and exhumation of midcrustal rocks along the northern edge of the inner tauride suture zone although northern regions of central anatolia contain the same protoliths as the nigde massif and underwent extensive tertiary magmatism they did not undergo similar extension suggesting that core complex development in south central turkey was controlled by the location of thickened and thermally weakened crust adjacent to a suture zone

k ar ages of granitoids unravel the stages of neo tethyan convergence in the eastern pontides and central anatolia turkey k ar dating of mineral separates extracted from various granitoid rock units of the eastern pontides and central anatolia turkey has provided some new insights unravelling various stages of the neo tethyan convergence system which evolved with northward subduction between the eurasian plate ep to the north and the tauride anatolide platform tap to the south along the izmir ankara erzincan suture iaes zone arc related granitoid rocks are only encountered in the eastern pontides and yield k ar cooling ages of both early cretaceous 138 5 2 2 ma early arc and late cretaceous ranging from 75 7 0 0 to 66 5 1 5 ma mature arc respectively the multi sourced granitoids of the eastern pontides with a predominant mantle component and k ar ages between 40 and 50 ma are considered to be a part of post collisional slab break off magmatism accompanied by tectonic denudation of pre late cretaceous granitoid rocks following juxtaposition of the ep and the tap around 55 50 ma in the eastern pontides the k ar cooling ages of collision related s i and a type granitoids in central anatolia reflect good synchronism between 80 and 65 ma suggesting a coeval genesis in a unique geodynamic setting but with derivation from various sources namely purely crustal purely mantle and or of mixed origin this sort of simultaneous generation model for these s i a type intrusives seems to be consistent with a post collisional lithospheric detachment related geodynamic setting i type granodioritic to tonalitic intrusives with k ar cooling ages ranging from 40 to 48 ma in east central anatolia are interpreted to have been derived from a post collisional within plate extension related geodynamic setting following the amalgamation of the ep and the tap in east central anatolia

mineralogy geochemistry and sr nd isotopes of the cretaceous leucogranite from karamadazi kayseri central turkey implications for their sources and geological setting the leucogranite is the major constituent of the bimodal late cretaceous karamadazi granitoid developed in relation with evolution of the inner tauride ocean along the northern margin of the taurides in central turkey new analyses of minerals major and trace elements including rare earth elements ree and of sr and nd isotopes are performed to determine the origin and geochemical characteristics of the leucogranites medium coarse grained leucogranite contains normally zoned plagioclase an12 20 mildly alkaline biotite and xenocrystic magneziohornblende actinolite and ferrohornblende it is characterized by concave up ree patterns with respect to middle heavy ree field relations mineral chemistry geochemical data and isotopic data suggest that the leucogranite could have originated from an amphibole bearing igneous source in lower to middle crust by low rate partial melting 40 under low pressure and low h2o activity conditions possibly coupled by mixing mingling with mafic magma and high level feldspar and minor biotite fractionation in contrast the quartz diorite and mafic microgranular enclave mme are probably developed from an enriched mantle with possible mingling mixing mme quartz diorite and leucogranite may represent a magmatic suite which formed in an extensional tectonic regime by bimodal magmatic activity probably because of lithospheric delamination or slab break off or after the alpine thicken within the gondwanan tauride anatolide platform initial sr data exhibit an age of 65 13 ma for the leucogranite but it does not indicate a true intrusion age of the magma due to isotopic modification of the magma

continuous measurements of riverine chemical constituents reveal the environmental effect of the 2014 2015 barðarbunga eruption in iceland abstract the 2014 2015 bar arbunga eruption caused one of the most intense and widespread volcanic derived air pollution events in centuries the volcanic plume was tracked all the way to central europe volcanic gas and aerosol dissolved in precipitation and accumulated as aerosol and snow on land in iceland here we report on the continuous monitoring of discharge and dissolved constituents of a direct runoff river located 85 km from the eruption site during the entire snowmelt period in 2015 osmotic samplers collected continuous water samples so short lived flood peaks would not be missed comparison between results from this 2015 study and data from 1998 to 2013 from the same river showed that average ph was 0 2 units lower in 2015 and the cl and so4 average concentration were 36 and 38 higher than prior to the eruption respectively integrated riverine fluxes of h and so4 were two to three times higher during summer 2015 than in the control years and the cl flux was 37 higher the measured excess h flux was however only a small fraction of the calculated excess h flux stemming from excess so4 and cl fluxes in 2015 which can be explained by ion exchange in the catchment soil water rock interaction consuming protons within the catchment and by elevated sea spray derived cl and so4 due to relatively high wind speed during the 2014 2015 winter in addition the small h increase in the river water can be the cause of the less than expected excess so4 riverine flux normalised to the total measured volcanogenic so2 and hcl emission fluxes 11 tg 0 1 tg which underscores the slow oxidation of so2 to so4 in relatively dry weather conditions and reduced sunlight during winter in iceland despite being sensitive to riverine ph and aluminium changes freshwater ecosystem was not threatened by the eruption since it did not cause large ph changes and the dissolved aluminium concentration was always low during the study period this study provided the means to quantify the integrated chemical fluxes and the impact of volcanic emissions on a riverine system in the vicinity of the eruption site and the implication of increased chemical fluxes of solutes of volcanic origin on the system

gold in turkey a missing link in tethyan metallogeny abstract the gold metallogeny of turkey constitutes a sector of the tethyan eurasian metallogenic belt temb within the alpine himalayan orogenic system that formed from jurassic cretaceous to the present this orogenic system produced many different types of deposits related to subduction collision post collision and rifting processes gold deposits as well as other mineral deposits of turkey are mainly concentrated in late mesozoic and tertiary rocks evaluation of the gold metallogeny of turkey is based on a gis database compilation of known gold deposits and prospects currently available data show that turkey has a gold endowment including reserves and resources of approximately 31 5 m oz 979 tonnes in 51 deposits 21 of which contain more than 0 2 m oz gold the other 30 deposits contain a total of approximately 1 m oz 31 tonnes gold resources two recent discoveries kisladag and copler currently contain total resources of 17 6 m oz au 549 tonnes more than 50 of the total turkish gold endowment turkey possesses a wide spectrum of gold deposits related to mesozoic and cenozoic volcanoplutonic arcs however porphyry gold copper epithermal gold including both high and low sulfidation styles and gold rich volcanic associated massive sulfide including both kuroko and cyprus types are the most economically important to date orogenic gold including listwanite hosted placer gold and skarn hosted gold are relatively less important or abundant deposit types other potential gold systems for exploration include carlin type gold detachment fault related gold iron oxide copper gold and gold in carbonate replacement and manganese deposits

crustal homogenization revealed by u pb zircon ages and hf isotope evidence from the late cretaceous granitoids of the agacoren intrusive suite central anatolia turkey geochemical and isotopic evidence from the agacoren igneous association in central anatolia turkey indicates that this suite of calc alkaline granitic rocks have undergone crustal homogenization during regional metamorphic and related magmatic events whole rock chemical and sr nd isotopic data of the granitoids reveal crustal affinity with an earlier subduction component zircons show inherited cores and subsequent magmatic overgrowths the laser ablation icp ms 206pb 238u zircon ages are determined as 84 1 1 0 ma for the biotite muscovite granite 82 3 0 8 1 1 ma for the hornblende biotite granite 79 1 2 1 1 5 ma for the granite porphyry dyke 75 0 1 0 1 0 ma for the alkali feldspar dyke and 73 6 0 4 ma for the monzonite this is interpreted as continuous magma generation possibly from heterogeneous sources from ca 84 to 74 ma during the closure of the northern branch of the neotethyan ocean the oldest granitoids 84 82 ma were probably formed due to crustal thickening after obduction of the morb type oceanic crust onto the tauride anatolide microplate the younger granitoids are interpreted to be related to the subsequent post collisional extension after lithospheric delamination combination of the laser ablation icp ms zircon lu hf isotope data with the u pb ages of inherited cores suggests that cretaceous granitoids formed by melting of heterogeneous crustal protoliths which results in significant variation in ehf t data from 12 9 to 2 2 these protoliths were probably composed of reworked early proterozoic crust minor juvenile late proterozoic magmatic components and paleozoic to pre late cretaceous recycled crustal material moreover the late cretaceous zircon domains of the different granitoids are characterized by a crustal signature with a relatively restricted zircon ehf t data ranging from 4 1 to 8 8 this variation is only about twice the reproducibility ca 1 ehf of the data but much smaller than the isotope variability of inherited zircons our preferred interpretation is effective isotopic homogenization of the heterogeneous central anatolian crust during the late cretaceous high grade metamorphic and magmatic events a process that we propose to be relevant for other active continental margins

aerosol formation in basaltic lava fountaining eyjafjallajokull volcano iceland 1 a short lived episode of basaltic lava fountaining at eyjafjallajokull volcano march april 2010 produced a low altitude ash poor plume we measured the composition of aerosol particles sampled using a cascade impactor and filter packs gases sampled using filter packs and volatile species scavenged by scoria and external water in order to investigate the formation and speciation of near source aerosol 0 4 m and its composition was dominated by chloride rather than sulfate we used two thermodynamic equilibrium models e aim and hsc chemistry v5 1 to show that the formation of particulate cl by condensation of hcl gas is more responsive to changes in ambient temperature than the oxidation of so2 to so42 so that a low so42 cl ratio in aerosol particles is characteristic of volcanic emissions in cold climates field measurements suggested that the efficiency of so2 to so42 conversion inside the vent increased with lower explosivity volatiles adsorbed on the surface of scoria had significantly higher so42 halogen molar ratios than the aerosol samples several potential explanations for these differences are discussed

unmanned aerial vehicle measurements of volcanic carbon dioxide fluxes i we report the first measurements of volcanic gases with an unmanned aerial vehicle uav the data were collected at la fossa crater vulcano italy during april 2007 with a helicopter uav of 3 kg payload carrying an ultraviolet spectrometer for remotely sensing the so 2 flux 8 5 mg d 1 and an infrared spectrometer and electrochemical sensor assembly for measuring the plume co 2 so 2 ratio by multiplying these data we compute a co 2 flux of 170 mg d 1 given the deeper exsolution of carbon dioxide from magma and its lower solubility in hydro thermal systems relative to so 2 the ability to remotely measure co 2 fluxes is significant with promise to provide more profound geochemical insights and earlier eruption forecasts than possible with so 2 fluxes alone the most ubiquitous current source of remotely sensed volcanic gas data

titanite and zircon fission track dating resolves successive igneous episodes in the formation of the composite kackar batholith in the turkish eastern pontides the kackar batholith in the turkish eastern pontides comprises several intrusive units with distinctive textural mineralogical and geochemical characteristics their titanite and zircon fission track ages confirm that the different lithodem units result from consecutive igneous episodes establish their emplacement sequence and together with geochemical data help to relate them to their geodynamic context the camlikaya granitoid 112 4 1 6 ma was emplaced during an immature arc magmatic episode of early cretaceous age the sirtyayla 57 1 1 2 ma and marselevat 52 9 1 3 ma granitoids are late products of a late palaeocene mature arc episode the ayder granitoid 46 4 1 0 ma is the result of middle to late eocene post collisional magmatism related to slab break off the halkalitas quartz diorite 43 7 2 3 ma and the gullubag monzonite 38 1 0 9 ma document a middle to late eocene episode related to post collisional extension the data reveal the advantages of dense sampling spanning a maximum range of elevations apart from the increased precision on the mean redundant sampling allows to shift the basis for interpretation from a priori assumptions to a posteriori numerical criteria when using geochronometers with low to moderate closure temperatures including apatite titanite and zircon fission tracks but also k ar ar ar biotite muscovite and k feldspar

apatite fission track data from central anatolian granitoids turkey constraints on neo tethyan closure 1 apatite fission track age versus elevation profiles and temperature time path modeling indicate an early to middle paleocene 57 62 ma rapid exhumation of the middle to late cretaceous granitoids in central anatolia and an oligocene 28 30 ma rapid exhumation of the eocene kosedag batholith in the ne sivas region part of eastern central pontides the early to middle paleocene rapid exhumation is thought to result from a regional compressional regime following the collision of the eurasian plate and the tauride anatolide platform at the closure of the izmir ankara erzincan branch of the northern neo tethys the oligocene accelerated exhumation of the kosedag batholith is contemporaneous with the oligo miocene closure of the southern neo tethys which juxtaposed the amalgamated eurasian and tauride anatolide platform and the african arabian plate along the bitlis zagros suture in southeast anatolia the compressional regime due to this collision affected a large area between the greater caucasus in the north and northern african arabian plate in the south

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

effects of plate convergence obliquity on timing and mechanisms of exhumation of a mid crustal terrain the central anatolian crystalline complex abstract apatite fission track ft ages from the central anatolian crystalline complex cacc a microcontinent within the turkish segment of the alpine himalayan orogen vary dramatically from north to south this variation correlates with differences in the obliquity of convergence of the continental fragment relative to the pontide belt for the northern cacc and the tauride belt for the southern cacc the northern cacc was deformed and metamorphosed during late cretaceous orogen normal collision and was exhumed from the mid crust to shallow crustal levels 50 ma to the present in contrast the southern cacc nigde massif was initially deformed and metamorphosed during late cretaceous contraction but subsequently developed as a metamorphic core complex in a wrench dominated regime and was exhumed to

mantle and crustal granites genetic classification of orogenic granites and the nature of their enclaves abstract the nature of enclaves must be taken into account in a genetic classification of granites granites containing only restites are different from those also containing basic magmatic enclaves microgranular enclaves if the former are of crustal origin the latter certainly include a mantle component rather than a distinction between s type granites of sedimentary origin and i type granites of igneous origin a distinction is made between c type granites crustal and m type granites mantle or mixed i e crustal mantle the c type granites can be subdivided into cs type anatexis of sedimentary rocks and ci type granites anatexis of igneous rocks in the french massif central the variscan granites belong to these different varieties leucogranites are typical c type granites whereas granodiorites and monzogranites are m type granites including various amounts of mantle component

magnetic fabric and microstructures of late paleozoic granitoids from the north patagonian massif evidence of a collision between patagonia and gondwana abstract widespread late paleozoic magmatism in northern patagonia is a target to test hypotheses on the long standing question over the origin of patagonia in recent years a dispute over whether it is an accreted crustal block that collided with gondwana in paleozoic times or an autochthonous part of south america has taken place as part of a multidisciplinary study an integrated microstructural and magnetic fabric study was carried out on the late carboniferous yaminue complex and the early permian navarrete plutonic complex both exposed in the northeastern corner of the north patagonian massif 40 5 s 67 0 w other investigated units are the late carboniferous tardugno granodiorite the newly defined cabeza de vaca granite and the late permian san martin pluton over 300 oriented cores from 60 sites were collected for anisotropy of magnetic susceptibility ams measurements a systematic analysis of around 100 petrographic thin sections was performed to characterize the microstructures of the different magmatic units microstructures in the yaminue complex are indicative of a transition from magmatic to solid state deformation microstructures of the orthogneiss of tonalitic composition suggest an early stage in the emplacement history of this complex the cabeza de vaca granite intrusive in yaminue complex is the most evolved unit and records less intense high temperature solid state deformation which suggests that the stress field that controlled the emplacement of the yaminue complex outlasted it according to petrologic and structural considerations the navarrete plutonic complex has been subdivided into three facies i e robaina guanacos and aranda respectively microstructures of the navarrete plutonic complex are mostly magmatic to submagmatic versus the solid state fabric that characterizes the robaina facies at the contact with the yaminue complex combined analyses of ams and microstructural data lead us to suggest that the yaminue complex cabeza de vaca granite and possibly tardugno granodiorite were intruded during a major compressional event associated with top to the ssw thrusting this event is most likely related to a frontal collision of the north patagonian massif and the southwestern gondwana margin at around 300 ma the navarrete plutonic complex and san martin pluton were emplaced after that tectonic event which must have ended by 281 ma previous magmatic geochronological and paleomagnetic data that suggest close connection of the north patagonian massif with the south american gondwana blocks during the paleozoic can be reconciled with a late paleozoic collision by a model of a para autochthonous north patagonian massif that rifted away from gondwana after the ordovician and collided again in the late carboniferous early permian

a single cause for uplift of the central and eastern anatolian plateau regional observations suggest that the central anatolian plateau central turkey has risen by 1 km since the tortonian 8 ma while significant crustal shortening did not occur this uplift was preceded by the onset of widespread volcanism 14 9 ma the lithospheric context of these events is however unknown for the eastern anatolian plateau similar events have been attributed to the late stage evolution of the northern neotethys slab resulting in delamination and slab breakoff recent tomographic results indicate that this slab extended beneath both below the eastern and central anatolian plateau just prior to delamination we propose a new lithospheric scenario for the regional evolution in the aegean anatolian near east region that combines a recent compilation of surface geology data with the structure of the upper mantle following the cretaceous eocene closure of the northern neotethys africa eurasia convergence was accommodated by horizontal subduction at a trench that was located south of anatolia like before the closure the northern neotethys slab continued to sink into the deeper mantle beneath the izmir ankara erzincan suture in the early miocene 20 15 ma the northern neotethys slab started to retreat southward to the trench resulting in delamination of the lithospheric mantle the last part of this scenario is testable whether delamination can explain the uplift of both the central and eastern anatolian plateau in the east uplift due to collision of arabia is included we use a coupled thermal flexural model of the lithosphere the model results show that delamination can explain the average present day long wavelength topography of the central anatolian plateau for the eastern anatolian plateau delamination explains half the present day elevation we find that a single delamination event also accounts for the present day surface heat flow and curie point depth in both plateaus we therefore propose to refer to central and east anatolia since the middle miocene as the anatolian plateau

high temperature mixtures of magmatic and atmospheric gases recent measurements of bro nox and near source sulfate in volcanic plumes suggest that volcanic vents might not simply act as point sources of emissions into the troposphere but may also act as high temperature reaction sites where mixtures of magmatic and ambient atmospheric gases may combine giving new and previously unexpected reaction products the detection of such species demands that a more complex model be developed for the interaction of volcanoes and atmospheres we show that general thermodynamic models can be applied successfully to volcanic gas equilibria by comparing the results from hsc chemistry with those from two volcanic gas equilibrium models solvgas and gasmix using a thermodynamic model optimized for volcanic gas chemistry c o s h f cl br i n ar speciation we show that the volume ratio of atmospheric gas to magmatic gas in a high temperature mixture is an important parameter of the volcanic plume chemistry and our results suggest that even small amounts of air a few for an h2o rich magmatic gas in the high temperature mixture are sufficient to yield elevated levels of reactive nitrogen halogen cl br and i and sulfur species within the volcanic plume further modifications of the plume chemistry may also occur due to low temperature reactions and chemical schemes for the modification of halogen cl br i nitrogen and sulfur chemistry are suggested within the constraints imposed by recent measurements

timing of post obduction granitoids from intrusion through cooling to exhumation in central anatolia turkey abstract the middle to late cretaceous central anatolian granitoids intrude the supra subduction zone type central anatolian ophiolite and medium to high grade metasediments of central anatolian crystalline complex and are overlain by late palaeocene to early middle eocene sediments their single zircon 207 pb 206 pb evaporation ages define three clusters 1 cenomanian turonian weighted mean age 94 9 3 4 ma 2 turonian santonian 85 5 5 5 ma and 3 campanian 74 9 3 8 ma their hornblende and biotite 40 ar 39 ar and k ar cooling ages cluster around 80 65 ma the close hornblende and biotite ages reflect rapid exhumation of a mid crustal section during the campanian maastrichtian early to middle palaeocene 57 62 ma apatite fission track age clusters date the tail end of this exhumation episode it is proposed that the central anatolian granitoid melts were generated in a post collisional extensional setting following the docking of an oceanic island arc onto the tauride anatolide platform campanian maastrichtian to early middle palaeocene rapid exhumation event is considered to result from continent continent collisions between eurasian plate and the tauride anatolide platform along the izmir ankara erzincan suture zone

reconstructing the geometry of central anatolia during the late cretaceous large scale cenozoic rotations and deformation between the pontides and taurides the central anatolian crystalline complex cacc exposes metamorphic ophiolitic and igneous rocks that were formed and deformed during closure of the neotethyan ocean the cacc is located in central turkey between the pontides in the north and the taurides in the south separated by major fault zones composite plutons intruded the meta sedimentary and ophiolitic units between 95 and 75 ma and form linear magmatic belts 100 km long along the western and northern margins of the cacc exhumation of the metamorphic and igneous complex was finalized by the paleocene time in this study we paleomagnetically study fifteen plutons spanning the entire non deformed upper cretaceous granitoid belt to test whether the initial configuration of the cacc was modified by vertical axis rotations after its exhumation our results show three internally coherent domains with significantly different vertical axis rotations 1 in the north east the akda block ayb records 151

geochemical characteristics of the composite kackar batholith generated in a neo tethyan convergence system eastern pontides turkey abstract the composite kackar batholith of cretaceous to late eocene age consists of various intrusions derived from different geodynamic settings ranging from early to mature arc through collision to post collisional extension in the neo tethyan convergence system of the eastern pontides of ne turkey the intrusions were emplaced into cretaceous and middle eocene volcano sedimentary units and are unconformably overlain by late cretaceous early to middle eocene and miocene units the 10 lithological units are grouped into five geodynamic associations on the basis of geological setting and geochemical characteristics 1 early arc origin as represented by the medium k calc alkaline calk camlikaya granitoid of early cretaceous age 2 mature arc origin as represented by the medium to high k calc alkaline sirtyayla and marselevat granitoids of late cretaceous to early palaeocene age 3 syn collisional plutonism as represented by the peraluminous asniyor leucogranite of palaeocene age 4 post collisional plutonism as represented by the high k calc alkaline ayder k feldspar megacrystic granitoid and the sasmistal microgranite of middle to late eocene age 5 the extension related mildly alkaline gullubag monzonite the medium k calc alkaline to slightly tholeiitic thol halkalitas quartz diorite and the low k tholeiitic ardesen gabbro and isina diabase of late eocene age that are mainly exposed as small shallow stocks and n s ne sw nw se and e w trending veins

the association of continental crust rocks with ophiolites in the northern apennines italy implications for the continent ocean transition in the western tethys abstract the late cretaceous sedimentary melanges from the external liguride units of the northern apennines include large slide blocks of ophiolites and lower and upper continental crust rocks representative of a continent ocean transition between the internal liguride oceanic domain and the thinned continental margin of the adria plate the slide blocks preserve a record of the long lived history of rifting which led to opening of the jurassic western tethys basin the external liguride ophiolites consist of 1 undepleted spinel peridoties partly re equilibrated under plagioclase facies conditions which were interpreted as unroofed subcontinental mantle 2 rare gabbroic rocks mainly troctolite to olivine bearing gabbro probably crystallised from n morb magmas and 3 basalts with n to t morb affinity covered by late callovian early oxfordian radiolarian cherts both gabbroic rocks and basalts locally intrude the mantle peridotites and postdate their re equilibration to plagioclase facies conditions the slide blocks of lower continental crust are composed of gabbro derived mafic granulites and felsic granulites the latter include quartzo feldspathic granulites and rare quartz poor to quartz free charnockitic rocks in both mafic and felsic granulites granulite facies re equilibration was followed by a retrograde metamorphic evolution to amphibolite greenschist and subgreenschist facies conditions retrogression is commonly accompanied by deformations progressively changing from plastic to brittle the upper crustal rocks occurring as slide blocks consist of hercynian granitoids with orogenic affinity mainly biotite bearing granodiorites and peraluminous two mica leucogranites locally the granitoids are intruded by basaltic dykes or capped by basaltic flows and radiolarian cherts the granitoids underwent polyphase brittle deformations under subgreenschist facies conditions which predated the basalt emplacement the tectono metamorphic evolution recorded by the slide blocks of the external liguride units started in the late carboniferous early permian about 290 ma with the emplacement at deep crustal levels of the gabbroic protoliths for the mafic granulites the associated felsic granulites likely represent the remnants of the lower continental crust intruded by the gabbro derived granulites mafic and felsic granulites subsequently underwent tectonic exhumation in permo triassic times as testified by the development of granulite to amphibolite facies ductile shear zones the granulites were finally exhumed to shallow levels probably in association with the subcontinental mantle in late triassic middle jurassic times the latter period was most likely characterized by extensive brittle faulting at shallow crustal levels thus giving rise to extensional allochthons formed by stretched slices of granitoids the western tethys opening is finally testified by the basalt intrusion and effusion in the late jurassic followed by deep sea pelagic sedimentation the external liguride crustal stratigraphy can be regarded as a fossil example of the transitional realm at the continent ocean boundary this reconstruction fits well with the available data on the present day continental margins derived from passive lithosphere stretching

assessment of petrophysical surface data of the harsit granitoid in trabzon in northeastern turkey the harsit granitoid in northeastern turkey comprises four separate granite units that are apparently unfoliated the harsit granitoid was investigated here by using microstructural petrofabric and anisotropy of magnetic susceptibility ams data the structural data of the granitoid were found to be highly compatible with the zonation recognized from ams measurements the orientation of magnetic fabrics within the granite units indicates that tectonic deformation might have occurred coevally with the magmatic emplacement of the intrusion when we evaluated the manners on the scale of the pluton that the disruption took place in the form of uplifting probably related to a rapid migration of the volcanic front and the documented change from deep sea sedimentation predominant until late cretaceous to shallower environments during the paleocene the possible tectonic control of fault systems on the ascent and emplacement of the granitic magma in the study area however cannot be completely ruled out because the harsit granitoid is situated at or very near the naf systems in northern anatolia in any case the intrusion is clearly discordant to the regional deformational features formed during the collisional events between the eurasia and anatolia plates in northern turkey

olivine basalt and trachyandesite peperites formed at the subsurface surface interface of a semi arid lake an example from the early miocene bigadic basin western turkey abstract miocene successions in western turkey are dominated by lacustrine fluvial and evaporitic sedimentary deposits these deposits include considerable amounts of volcaniclastic detritus derived from numerous ne trending volcanic centres in western turkey as well as in the bigadic region early miocene syn depositional ne trending olivine basalt and trachyandesite bodies that formed as intrusions and lava flows occur within the bigadic borate basin olivine basalts occur as partly emergent intrusions and trachyandesite dykes fed extensive lava flows emplaced in a semi arid lacustrine environment peperites associated with the olivine basalt and trachyandesites appear to display contrasting textural features although all the localities include a large variety of clast morphologies from blocky to fluidal fluidal clasts mainly globular ameboidal and pillow like varieties are widespread in the peperite domains associated with olivine basalts apparently due to large volume sediment fluidisation in contrast fluidal clasts related to trachyandesites are restricted to narrow zones near the margins of the intrusions and have commonly elongate and polyhedral shapes with digitate margins rather than globular and equant varieties blocky and fluidal clasts in the olivine basalt peperite display progressive disintegration suggesting decreasing temperature and increasing viscosity during fragmentation abundance of blocky clasts with respect to fluidal clasts in the trachyandesite peperite indicates that the fluidal emplacement and low volume sediment fluidisation in the early stages were immediately followed by quench fragmentation due to the high viscosity of the magma size texture and abundance of the blocky and fluidal clasts in the olivine basalt and trachyandesite peperites were mainly controlled by sediment fluidisation pulsatory magma injection and magma properties such as composition viscosity vesicularity and size abundance and orientation of phenocrysts variously combining these contrasting features to varying degrees may form diverse juvenile clast shapes in peperitic domains

k ar age whole rock and isotope geochemistry of a type granitoids in the divrigi sivas region eastern central anatolia turkey abstract the bimodal a type dumluca and murmana granitoids consist of felsic monzonitic syenitic and mafic gabbroic dioritic and monzogabbroic monzodioritic rocks which were intruded into the cenomanian turonian supra subduction zone type divrigi ophiolitic melange new hornblende and biotite k ar dates yield cooling ages ranging from 72 to 77 ma and from 68 to 77 ma for the felsic and mafic rocks respectively in the dumluca and murmana granitoids felsic and mafic rocks of these intrusions have a metaluminous high k alkaline composition however highly evolved members of the felsic rocks are peraluminous in character trace element geochemistry data indicate that mafic and felsic rocks have their own geochemical characteristics which show different sources the combined evidence of the trace element radiogenic and stable isotope geochemistry from the dumluca and murmana granitoids suggest that the mafic rocks were derived exclusively from an enriched mantle mafic magma em ii but the felsic rocks were derived from a hybrid felsic magma the hybrid felsic magma was generated by the mixing of the mantle derived mafic with another crustal derived silicic melt the composition of some mafic rocks from murmana granitoid suite is thought to be derived from an enriched mantle source that may have been metasomatized by earlier subduction derived fluids thus carrying the subduction signature in the source material the local and regional geology suggest an early late cretaceous post collisional extension related geodynamic setting following the collision between the tauride anatolide platform and an oceanic island arc comprising the supra subduction zone type central anatolian ophiolite

207pb 206pb single zircon evaporation ages of some granitoid rocks reveal continent oceanic island arc collision during the cretaceous geodynamic evolution of the central anatolian crust turkey abstract 207pb 206pb single zircon evaporation age determinations carried out on nine different granitoid units of central anatolia turkey have yielded three distinct granitoid groups with different emplacement ages these are 1 cenomanian turonian granitoids with a weighted mean age wma of 94 9 3 4 ma 2 turonian santonian granitoids with a wma of 85 5 5 5 ma and 3 campanian granitoids with a wma of 74 9 3 8 ma the spatial and temporal relationships between the formation of the metamorphic sole of the supra subduction zone type central anatolian ophiolite ssz type cao crustal metamorphism of the central anatolian crystalline complex cacc and the emplacement of cenomanian turonian to turonian santonian granitoids indicate a geodynamic setting in which all these geological events occurred quasi simultaneously in central anatolia such a geodynamic setting is thought to be related to the cenomanian turonian collision of the tauride anatolide platform tap and an oceanic island arc including the ssz type cao the campanian granitoids appear to be the continuation of this collision related protracted magmatism in central anatolia

investigation of the complex dynamics and structure of the 2010 eyjafjallajokull volcanic ash cloud using multispectral images and numerical simulations 1 we investigated the structure and evolution of the 2010 eyjafjallajokull volcanic cloud and its dispersal over iceland and europe integrating satellite multispectral images and numerical simulations data acquired by medium resolution imaging spectrometer meris and advanced spaceborne thermal emission and reflection radiometer aster have been analyzed to quantify the cloud extent and composition the vol calpuff dispersal code was applied to reconstruct the transient and 3 d evolution of the cloud source parameters estimated on the base of available a posteriori volcanological data sets have been used quantitative comparisons between satellite retrievals and modeling results were performed for two selected instants of time during the first and third eruptive phases on a regional scale sensitivity of the model to initial volcanological conditions has been analyzed at continental scale several complex non intuitive features of cloud dynamics have been highlighted and strengths and limitations of the adopted methods identified the main findings are the level of quantitative agreement between satellite observations and numerical results depends on ash cloud composition particle sizes and concentration with better agreement for smaller particles and higher concentrations the agreement between observations and modeling outcomes also depends on the temporal stability of volcanological conditions and the complexity of the meteorological wind field the irregular dispersion of ash as reconstructed from satellite data and numerical modeling can be well explained by the different response of particle sizes to strong vertical wind shear and by resuspension processes acting at ground level eruptive source conditions are the main source of uncertainty in modeling especially during an ongoing crisis and at long range scales