paleogeographic and paleotectonic implications of clay mineral distribution in late jurassic early cretaceous sediments of the pindos olonos and beotian basins greece abstract a new method is proposed for solving the controversial problem of the location of oceanic areas from which the pindos and othrys ophiolites originated assuming that clay fractions quickly disseminated over large areas may be reliable markers of erosional processes we studied these fractions in sediments from two external basins pindos olonos and beotian located between the main carbonate platforms of the greek hellenids chronologically two different clay associations can be distinguished in the sedimentary sequences of the basins the lower one is dominated by illite and subregular illite smectite mixed layers and poor in mg ni and cr this association is consistent with common continental sources the upper one appearing in late tithonian synchroneously in both basins consists of trioctahedral smectite saponite type enriched in fe mg ni and cr they are considered to be derived from weathered ophiolites thus the beginning of the ophiolite detrital sedimentation accepted as being middle to late bathonian in the basinal sequences of the maliac or othrys zone from hydra or lower middle oxfordian in all the internal units in the argolis peninsula is much younger late tithonian in the external basins such a diachronism is not consistent with a model postulating initial ophiolite displacements within the pindos olonos basin by late jurassic time it suggests that a platform was acting as a barrier between the site of the ophiolite first intra oceanic deformation and the external basins this barrier cannot be the parnassus platform that kept subsiding in neritic environments until late cretaceous inside the external basins it is likely to be the pelagonian platform positively known to have been submerged during the tithonian consequently we conclude that there was no genetic relationships between the external basins pindos olonos basin in a broad sense and the pindos ophiolites of which the zone of origin is to be located on the opposite eastern internal side of the pelagonian platform

on the hellenic subduction zone and the geodynamic evolution of crete since the late middle miocene abstract in recent syntheses of the geodynamic evolution of the aegean area the hellenic subduction zone and in particular its initiation plays a central role two basic aspects of the recent comprehensive model put forward by le pichon angelier and co workers are a initiation of subduction along the hellenic arc is inferred to have taken place approximately 13 ma ago whereas several others have suggested approximately 5 ma and b migration of the trench system to the south southwest giving rise to an extensional regime in the back arc region which led to general subsidence and formation of the present day aegean sea new data on the structure of the upper mantle underneath the aegean area indicate that the former aspect requires modification the seismic velocity structure indicating a northward dipping slab down to a depth of at least 600 km and the depth distribution of earthquake hypocenters can not be reconciled with straightforward initiation of subduction approximately 13 ma ago estimates of about 5 ma for the time of initiation of the present subduction zone are even more difficult to reconcile assuming 400 km as an upper bound for the effect of stretching of the aegean sea and of other processes contributing to the separation of crete from the eurasian mainland we arrive at an age for the hellenic subduction zone of at least 26 ma as to aspect b geological data of crete lend strong support to the idea that on crete compressional tectonics is of much greater importance than current models imply combining geophysical and geological data we propose a modification of the tectonic evolution for the cretan segment of the hellenic arc whereas the basic process of extension caused by a migrating trench system roll back in a land locked basin remains a very useful and sound concept the tectonics of the margins of a region subject to stretching in this case crete may be more complicated than hitherto thought in our model the documented fragmentation of crete into several basins which started about 12 ma ago is not attributed to initiation of subduction but to inception of the roll back process compressional tectonics on crete is taken to be associated with deformation of the crust resulting from the overall tensional stress regime

timing kinematics and cause of aegean extension a scenario based on a comparison with simple analogue experiments abstract since the early 1970s most geodynamic models proposed for the eastern mediterranean consider that the initiation of extension in the aegean during the late middle miocene or later was a direct consequence of the westward extrusion of anatolia away from the arabia eurasia collision front in the late 1990s a few models have taken into account the increasing evidence for an earlier initiation of aegean extension arising mostly from the analysis of deformation within the various alpine metamorphic complexes of the area based largely on our own investigations we first present a review of the data that reliably constrain the minimum age for the initiation of extension in these complexes it shows that regional scale extension with a pattern of stretching orientations similar to that of the pliocene pleistocene was already strongly active in the aegean before the onset of arabian indentation into eurasia lower miocene vs middle or upper miocene this implies that the initiation of aegean extension did not result from the lateral extrusion of anatolia instead extension may have started owing to a process of gravity spreading of the continental lithosphere that had previously been thickened during alpine collision the main arguments favouring this interpretation are presented and a preliminary scenario is proposed for the neogene evolution of the eastern mediterranean in which lateral extrusion of anatolia occurred lately during southward spreading of the aegean lithosphere in order to test this hypothesis further physical experiments simulating the horizontal spreading of a continental lithosphere toward a free boundary have been carried out the analysis of various elements of the deformation field displacements strain rotations fault pattern and kinematics both in the experiments and in the aegean domain reveals an excellent agreement between the two not only do early stages of aegean extension appear to fit the gravity spreading hypothesis but so does the recent to present internal deformation of the aegean transverse e w active shortening observed in the northern aegean is commonly taken as one of the most striking pieces of evidence that aegean extension results from the lateral extrusion of anatolia the experiments indicate that such transverse shortening may equally develop as a result of pure gravity spreading associated with a pattern of faults and rotations that compares well with that of the northern aegean pure dextral shearing along some strands of the north aegean trough fault system and the related development of an asymmetric pattern of faults in the northern aegean are eventually the only features that evidently arise from the extrusion of anatolia since less than 3 ma finally we argue that during the early stages of aegean extension since at least 21 ma and until ca 11 ma the distribution of extensional strain on a regional scale has been controlled by the distribution of earlier thickening post thickening thermal weakening through partial melting of deep levels of the crust probably accounts for the localization of extensional strain within the areas of thick crust restoring the aegean in its most likely configuration at the onset of bulk crustal extension suggests that 1 the extensional strain rate remained roughly constant or has eventually decreased since the onset of aegean extension and 2 the amounts of extension before and after 16 ma have been roughly equal

evidence for neotethys rooted within the vardar suture zone from the voras massif northernmost greece abstract three conflicting models are currently proposed for the location and tectonic setting of the eurasian continental margin and adjacent tethys ocean in the balkan region during mesozoic early tertiary time model 1 places the eurasian margin within the rhodope zone relatively close to the moesian platform a tethyan oceanic basin was located to the south bordering a large serbo pelagonian microcontinent model 2 correlates an integral serbo pelagonian continental unit with the eurasian margin and locates the tethys further southwest model 3 envisages the pelagonian zone and the serbo macedonian zone as conjugate continental units separated by a tethyan ocean that was sutured in early tertiary time to create the vardar zone of northern greece and former yugoslavia these published alternatives are tested in this paper based on a study of the tectono stratigraphy of a completely exposed transect located in the voras mountains of northernmost greece the outcrop extends across the vardar zone from the pelagonian zone in the west to the serbo macedonian zone in the east within the voras massif six east dipping imbricate thrust sheets are recognised of these units 1 4 correlate with the regional pelagonian zone in the west and related almopias sub zone by contrast units 5 6 show a contrasting tectono stratigraphy and correlate with the paikon massif and the serbo macedonian zone to the east these units form a stack of thrust sheets with unit 1 at the base and unit 6 at the top unstacking these thrust sheets places ophiolitic units between the pelagonian zone and the serbo macedonian zone as in model 3 additional implications are first that the paikon massif cannot be seen as a window of pelagonian basement as in model 1 and secondly jurassic andesitic volcanics of the paikon massif locally preserve a gneissose continental basement ruling out a recently suggested origin as an intra oceanic arc we envisage that the almopias vardar ocean rifted in triassic time followed by seafloor spreading the almopias ocean was consumed beneath the serbo macedonian margin in jurassic time generating subduction related arc volcanism in the paikon massif and related units ophiolites were emplaced onto the pelagonian margin in the west and covered by late jurassic pre kimmeridgian conglomerates other ophiolitic rocks formed within the vardar zone ano garefi ophiolite unit 4 in latest jurassic early cretaceous time and were not deformed until early tertiary time the vardar zone finally sutured in the early tertiary creating the present imbricate thrust structure of the voras mountains

new radiolarian biostratigraphic age constraints on middle triassic basalts and radiolarites from the inner hellenides northern pindos and othris mountains northern greece and their implications for the geodynamic evolution of the early mesozoic neotethys the avdella melange in the northern pindos mountains and its equivalent formation the loggitsion unit in the othris mountains expose early mesozoic mid late triassic oceanic fragments beneath the western greek ophiolite belt of the inner hellenides northern greece the melange consists of locally interfingering blocks and slices of ribbon radiolarite radiolarian chert and pillow basalt and is usually overthrust by jurassic ophiolites new middle and upper triassic radiolarian biostratigraphic data are presented from radiolarites and basalt radiolarite sequences within melange blocks pillow basalts associated with the radiolarites provide clues to the opening of the neotethyan ocean basin the radiolarians indicate a middle triassic age latest anisian probably early illyrian which is documented for the first time in the northern pindos mountains the new radiolarian biostratigraphic data suggest that rift type basalt volcanism already began in pre ladinian time late scythian anisian these basalts were then overlain by upper anisian to carnian norian radiolarites

cretaceous to cenozoic thermal evolution of the southwestern south carpathians evidence from fission track thermochronology abstract the southwestern south carpathian orogen is composed of various nappe complexes which were assembled during the cretaceous cenozoic orogeny these are from footwall to hangingwall 1 the danubian nappe complex including a cadomian variscan basement 2 the arjana and severin units with jurassic to early cretaceous rift and oceanic sequences and 3 the getic nappe complex with variscan continental basement fission track ft thermochronology on apatite zircon and sphene from samples collected from various units of the south carpathians in conjunction with field constraints and previous geochronology is used to characterise the alpine tectonic events and to restore the pattern and amount of exhumation since the cretaceous zircon from the flysch unit and the danubian liassic cover sequence yields ft ages around 200 ma suggesting cooling of the rift flanks prior to the opening of the severin rift zircon and sphene from the getic and danubian basement units yield ft ages averaging 110 ma and indicating cooling under 240 c of the basement contemporaneous with or postdating thrusting apatite ft ages display a decreasing age trend from the hangingwall 65 ma to the footwall units 30 ma the age data and corresponding horizontal confined track length distributions suggest that exhumation of the nappe pile occurred in two stages the first is related to the late cretaceous nappe stacking and the second one to the final thrusting of the south carpathians onto the top of the moesian platform apatite ft ages along major brittle wrench faults indicate reheating above ca 120 c during fluid flow associated with fault re activation during oligocene and neogene times thus shear zone rocks experienced a higher temperature overprint during cenozoic time than rocks of the unaffected nappe pile temperatures of hydrothermal flow along these zones decreased below 100 c progressively starting with the late oligocene early miocene when the area began to override the moesian platform

tectonostratigraphic models of the alpine terranes and subduction history of the hellenides abstract the tectonostratigraphy of the hellenic terranes is related to their paleogeodynamic and paleogeographic evolution which comprises three major stages i continental rifting in the northern margin of gondwana characterised by volcanosedimentary complexes of late paleozoic triassic ii continental drifting and contemporaneous oceanic opening of tethyan basins in between the continental terranes during triassic paleogene with shallow water carbonate platforms on the continental terranes and ophiolite suites interlayered with pelagic sediments within the tethyan basins iii accretion of the tectonostratigraphic terranes with docking along the active european margin characterised by flysch melange sedimentation along the trenches from early jurassic to neogene two tectonostratigraphic models can be distinguished one for the continental terranes carbonate platforms and another for the oceanic basins the duration of each geodynamic stage for each terrane is obtained from the chronology of the tectonostratigraphic facies change the general trend is younger ages observed in the southern terranes and older ages towards the northern terranes the two alternative tectonostratigraphic models are applied in the two groups of terranes and the chronology of the geodynamic paleogeographic stages is estimated the hellenic subducted slab as shown in the seismic tomographic images is correlated to the terrane paleogeography using the estimated widths and the average subduction rates the upper 1700 km of the slab correspond to the three southern more external terranes whereas the remainingpart of the slab may represent the other more internal terranes a palinspastic model of the hellenides is presented taking into account the chronology of each stage for every terrane obduction of ophiolites over the southern platforms is observed in all four oceanic basins blueschist exhumation formation of core complexes and tectonic windows through extensional detachments occur after micro collision of continental terranes platforms and their isostatic uplift within the upper plate after their detachment from the subducting slab

porphyry cu mo au deposits related to melting of thickened mafic lower crust examples from the eastern tethyan metallogenic domain abstract most porphyry cu deposits in the world occur in magmatic arc settings and are formed in association with calc alkaline arc magmas related to subduction of oceanic lithosphere this contribution reviews a number of significant porphyry cu deposits in the eastern tethyan metallogenic domain they widely occur in a variety of non arc settings varying from post late collisional transpressional and extensional environments to intracontinental extensional environments related to orogenic and anorogenic processes their spatial temporal localization is controlled by strike slip faults orogen transverse normal faults lineaments and their intersections in these non arc settings these deposits are dominated by porphyry cu mo deposits with minor porphyry cu au and epithermal au deposits and exhibit a broad similarity with those in magmatic arcs the associated magmas are generally hydrous relatively high fo2 high k calc alkaline and shoshonitic and show geochemical affinity with adakites they are distinguished from arc magmas and or oceanic slab derived adakites by their occurrence as isolated complexes high k2o contents 1 2 8 5 and much wider range of end t values 10 to 3 and positive ehf t values 4 6 to 6 9 these potassic magmas are most likely formed by partial melting of thickened juvenile mafic lower crust or delaminated lower crust but also involving various amounts of asthenospheric mantle components key factors that generate hydrous fertile magmas are most likely crust mantle interaction processes at the base of thickened lower crust in non arc settings rather than oceanic slab dehydration as in arc settings breakdown of amphibole in thickened lower crust e g amphibole eclogite and garnet amphibolite during melting is considered to release fluids into the fertile magmas leading to an elevated oxidation state and higher h2o content necessary for development of porphyry cu mo au systems copper and au in hydrous magmas are likely derived from mantle derived components and or melts which either previously underplated and infiltrated at the base of the thickened lower crust or were input into the primitive magmas by melt mantle interaction in contrast mo and part of the s in the fertile magmas are probably supplied by old crust during melting and subsequent ascent

the structures stratigraphy and evolution of the gulf of corinth rift greece summary a multichannel seismic and bathymetry survey of the central and eastern gulf of corinth goc greece reveals the offshore fault geometry seismic stratigraphy and basin evolution of one of earths most active continental rift systems active right stepping en echelon north dipping border faults trend ese along the southern gulf margin significantly overlapping along strike the basement offsets of three akrata derveni sithas and xylocastro are linked the faults are biplanar to listric typically intermediate angle 35 in the centre and 45 48 in the east near the surface but decreasing in dip and or intersecting a low or shallow angle 15 20 in the centre and 19 30 in the east curvi planar reflector in the basement major s dipping border faults were active along the northern margin of the central gulf early in the rift history and remain active in the western gulf and in the subsidiary gulf of lechaio but unlike the southern border faults are without major footwall uplift much of the eastern rift has a classic half graben architecture whereas the central rift has a more symmetric w or u shape the narrower and shallower western gulf that transects the 40 km thick crust of the hellenides is associated with a wider distribution of overlapping high angle normal faults that were formerly active on the peloponnesus peninsula the easternmost sector includes the subsidiary gulfs of lechaio and alkyonides with major faults and basement structures trending ne e w and nw the basement faults that control the rift architecture formed early in the rift history with little evidence other than the vrachonisida fault along the northern margin in the marine data for plan view evolution by subsequent fault linkage several have maximum offsets near one end crestal collapse graben formed where the hanging wall has pulled off the steeper onto the shallower downdip segment of the derveni fault the dominant strikes of the corinth rift faults gradually rotate from 090 120 in the basement and early rift to 090 100 in the latest rift reflecting a 10 rotation of the opening direction to the 005 presently measured by gps the sediments include a locally 1 5 km thick early rift section and a late rift section also locally 1 5 km thick that we subdivide into three sequences and correlate with seven 100 ka glacio eustatic cycles the gulf depocentre has deepened through time currently 700 mbsl as subsidence has outpaced sedimentation we measure the minimum total horizontal extension across the central and eastern gulf as varying along strike between 4 and 10 km and estimate full values of 6 11 km the rift evolution is strongly influenced by the inherited basement fabric the regional nnw structural fabric of the hellenic nappes changes orientation to ese in the parnassos terrane facilitating the focused north south extension observed offshore there the basement penetrating faults lose seismic reflectivity above the 4 14 km deep seismogenic zone multiple generations and dips of normal faults some cross cutting accommodate extension beneath the goc including low angle 15 20 interfaces in the basement nappes the thermally cool forearc setting and cross orogen structures unaccompanied by magmatism make this rift a poor analogue and unlikely precursor for metamorphic core complex formation

exhumation of high pressure rocks driven by slab rollback rocks metamorphosed under high pressure hp and ultra high pressure uhp conditions in subduction zones come back to the surface relatively soon after their burial and at rates comparable to plate boundary velocities in the mediterranean realm their occurrence in several belts related to a single subduction event shows that the burial exhumation cycle is a recurrent transient process using the calabria apennine and aegean belts as examples we show that the exhumation of hp rocks is associated in time and space with the subduction of small continental lithosphere blocks that triggers slab rollback creating the necessary space for the exhumation of the buoyant continental crust that was deeply buried just before the buoyancy force of the subducted crust increases until this crust detaches from the downgoing slab it then exhumes at a rate that depends directly on the velocity of trench retreat to become part of the overriding plate heated from below by the asthenosphere that flows into the opening mantle wedge the exhumed crust weakens and undergoes core complex type extension responsible for a second stage of exhumation at a lower rate the full sequence of events that characterizes this model crust mantle delamination slab rollback and trench retreat hp rock exhumation asthenosphere heating and core complex formation arises entirely from the initial condition imposed by the subduction of a small continental block no specific condition is required regarding the rheology and erosion rate of hp rocks the burial exhumation cycle is transient and can recur every time a small continental block is subducted

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

on the hydrography of denmark strait using 111 shipboard hydrographic sections across denmark strait occupied between 1990 and 2012 we characterize the mean conditions at the sill quantify the water mass constituents and describe the dominant features of the denmark strait overflow water dsow the mean vertical sections of temperature salinity and density reveal the presence of circulation components found upstream of the sill in particular the shelfbreak east greenland current egc and the separated egc these correspond to hydrographic fronts consistent with surface intensified southward flow deeper in the water column the isopycnals slope oppositely indicative of bottom intensified flow of dsow an end member analysis indicates that the deepest part of denmark strait is dominated by arctic origin water with only small amounts of atlantic origin water on the western side of the strait the overflow water is a mixture of both constituents with a contribution from polar surface water weakly stratified boluses of dense water are present in 41 of the occupations revealing that this is a common configuration of dsow the bolus water is primarily arctic origin water and constitutes the densest portion of the overflow the boluses have become warmer and saltier over the 22 year record which can be explained by changes in end member properties and their relative contributions to bolus composition

aegean tectonics strain localisation slab tearing and trench retreat abstract we review the geodynamic evolution of the aegean anatolia region and discuss strain localisation there over geological times from late eocene to present crustal deformation in the aegean backarc has localised progressively during slab retreat extension started with the formation of the rhodope metamorphic core complex eocene and migrated to the cyclades and the northern menderes massif oligocene and miocene accommodated by crustal scale detachments and a first series of core complexes mccs extension then localised in western turkey the corinth rift and the external hellenic arc after messinian times while the north anatolian fault penetrated the aegean sea through time the direction and style of extension have not changed significantly except in terms of localisation the contributions of progressive slab retreat and tearing basal drag extrusion tectonics and tectonic inheritance are discussed and we favour a model 1 where slab retreat is the main driving engine 2 successive slab tearing episodes are the main causes of this stepwise strain localisation and 3 the inherited heterogeneity of the crust is a major factor for localising detachments the continental crust has an inherited strong heterogeneity and crustal scale contacts such as major thrust planes act as weak zones or as zones of contrast of resistance and viscosity that can localise later deformation the dynamics of slabs at depth and the asthenospheric flow due to slab retreat also have influence strain localisation in the upper plate successive slab ruptures from the middle miocene to the late miocene have isolated a narrow strip of lithosphere still attached to the african lithosphere below crete the formation of the north anatolian fault is partly a consequence of this evolution the extrusion of anatolia and the aegean extension are partly driven from below asthenospheric flow and from above extrusion of a lid of rigid crust

palaeogeography of the western pelagonian continental margin in beotia greece during the cretaceous biostratigraphy and isotopic compositions δ13c δ18o of calcareous deposits the palaeogeography of beotia greece during the cretaceous is outlined on the basis of biostratigraphic evidence derived predominantly from the distribution of rudist bivalves and planktonic foraminifera observed facies trends are evaluated together with carbon and oxygen isotopic compositions of limestones and rudist shells the interaction between global sea level fluctuations and gradual subsidence of the pelagonian continental margin controlled facies distribution during most of the cretaceous the sedimentary record begins with berriasian flysch type deposits that accumulated during incipient eohellenian orogenic movements barremian deposits with similar sedimentological characteristics probably belong to the same tectonostratigraphic unit during aptian cenomanian times terrigenous clastics with a few intercalated marine limestones accumulated in south beotia the fossil content of patch reefs presents important biostratigraphic marks in this terrigenous sequence carbon and oxygen isotopic compositions recorded unstable marine environments and subsequent decrease of continental influx continuous subsidence and rising sea levels are evident in the late turonian onlap of rudist limestones on the eohellenian basement of the ptoon mountains as well as in the interfingering of calcareous slope deposits and basinal globotruncana mudstones of south beotia during late coniacian early santonian a marked regression finally led to a regional emersion and the development of a karst relief this regression is predated by heavy oxygen isotopic compositions in the coniacian limestones which probably resulted from isolation of a larger marine embayment from oceanic circulation the subsequent late santonian campanian transgression flooded all of beotia its sediments lie over allochthonous laterites extended rudist biostromes developed as soon as continental influx ceased as indicated both by the stable isotope compositions of rudish shells and embedding limestones during the late campanian the rather uniform platform type depositional environments differentiated and pelagic sedimentation recurred in south beotia whereas depositional environments to the north remained shallow incipient tectonics movements were responsible for a late maastrichtian emersion of north beotia while basinal conditions persisted in the south the onset of flysch type sedimentation occurred simultaneously during the late paleocene in north beotia as well as in the adjacent parnassus and pindos zones however this important facies transition has not yet been precisely dated in south beotia

the cretaceous sedimentary history of the pindos basin greece the cretaceous sedimentary rocks of the pindos zone in western greece document the evolution of a tethyan deep water basin new sedimentological and micropalaeontological studies reveal a complex basin history siliceous sediments with abundant radiolaria and organic rich facies prevailed up to the early late cretaceous within the sediment starved pre middle cenomanian marked black shale levels appear that are probably linked to oceanic anoxic events at the change from the late early to the early middle cenomanian the sedimentary regime altered abruptly the early late cretaceous is characterized by major calcareous redepositional events orbitoline horizons and often associated siliciclastic turbidite deposition submarine fan environments in the late late cretaceous carbonate supply increased rapidly resulting in the evolution of a carbonate slope and basin plain setting pelagic and allodapic limestones recorded basinwide blooms in planktonic foraminifera elevata event and a polyphase redepositional history that is interpreted to reflect the sensitivity of the basin to the tectonic evolution of apulia

new insights from 40ar 39ar laserprobe dating of white mica fabrics from the pelion massif pelagonian zone internal hellenides greece implications for the timing of metamorphic episodes and tectonic events in the aegean region

structure and variability of the shelfbreak east greenland current north of denmark strait abstractdata from a mooring array deployed north of denmark strait from september 2011 to august 2012 are used to investigate the structure and variability of the shelfbreak east greenland current egc the shelfbreak egc is a surface intensified current situated just offshore of the east greenland shelf break flowing southward through denmark strait this study identified two dominant spatial modes of variability within the current a pulsing mode and a meandering mode both of which were most pronounced in fall and winter a particularly energetic event in november 2011 was related to a reversal of the current for nearly a month in addition to the seasonal signal the current was associated with periods of enhanced eddy kinetic energy and increased variability on shorter time scales the data indicate that the current is for the most part barotropically stable but subject to baroclinic instability from september to march by contrast in summer the current is mainly confined to the shelf break with

the continuity of active fault systems in greece summary evidence from geomorphology the distribution of large earthquakes and geodetic measurements suggests that the active faulting in mainland greece and the north aegean sea is concentrated into a small number of discrete linear zones that bound relatively rigid blocks on land the zones are most clearly identified where the faulting is associated with large escarpments particularly in hard footwall rocks the zones can become indistinct and diffuse near their ends sometimes because they enter high unstable topography where landsliding obscures the fault morphology but mostly because the extension rates decrease along strike as a consequence of the relative rotation of the blocks they bound the main graben systems of chalkidiki southern thessaly and the north gulf of evia all seem to connect with the strike slip faulting in the offshore aegean and to die out in the west a configuration related to clockwise rotations in east central greece by contrast the gulf of corinth which is the fastest opening graben system in greece opens more rapidly in the west than the east both these features of the gulf of corinth are consequences of the motion of the south aegean and peloponnese as a single block late pliocene and quaternary geology and geomorphology indicate that the boundaries of the rigid blocks in central greece have changed over that time with faulting migrating into the hanging walls sometimes changing in orientation these changes are probably related to the way faulting in the seismogenic layer adapts to block rotation so as to maintain the general features of a velocity field that is controlled by larger scale effects such as buoyancy forces and the seaward migration of the subducting slab beneath crete the image of greece as a mosaic of rigid blocks whose boundaries change with time is a useful framework for seismic hazard evaluation but we emphasize that some moderate sized earthquakes do occur away from the main fault zones within the relatively rigid blocks and especially near their diffuse ends

the carpatho balkanides and adjacent area a sector of the tethyan eurasian metallogenic belt the tethyan eurasian metallogenic belt temb was formed during mesozoic and post mesozoic times in the area of the former tethyan ocean on the southern margin of eurasia with the afro arabian and indian plates to the south it extends from western mediterranean via the alps and southeastern europe through the lesser caucasus the hindu kush and the tibet plateau to burma and sw indonesia linking with the west pacific metallogenic belt the carpatho balkan region is one of the sectors of the temb characterized by some specific features the emplacement of ore deposits is related to a definite time interval and to specific tectonic settings such as

hydraulic estimates of denmark strait overflow 1 upper bounds of the denmark strait deep water overflow from the nordic seas into the north atlantic are estimated using rotating hydraulic theory the calculations are made for the real bottom topography of the strait and are based on hydrographic sections surveyed during a dedicated field experiment in the area results are presented for zero as well as finite but constant potential vorticity and it is shown that the differences in outcome between these two approaches are only minor the calculated interface configurations are found to be in good agreement with those observed and the theoretically obtained transports conform with earlier estimates

tectonic development of the vardar ocean and its margins evidence from the republic of macedonia and greek macedonia abstract the tectonic development of the northeast margin of the korabi pelagonian continent and the adjacent vardar ocean is discussed based on study of nine traverses across the former northeastern margin of the korabi pelagonian continent represented by the west vardar subzone in the republic of macedonia a detailed correlation of units is also made across the international border with greece coupled with regional comparisons precambrian palaeozoic units were metamorphosed and intruded by granitic rocks followed by mid triassic rifting and the construction of a carbonate platform bordering a late triassic early jurassic ocean neritic deposition was followed by late jurassic syn or pre early tithonian subsidence with radiolarian and then terrigenous turbidite sedimentation overlying ophiolitic rocks are characterised by a relatively thin 200 km n s sheet of sheared blocky serpentinite mainly mantle harzburgite associated with ophiolite derived debris flows the emplaced ophiolitic rocks were subaerially weathered to form local fe ni accumulations following marine transgression a shallow water carbonate siliciclastic deposits including coralgal reefs accumulated during late tithonian early cretaceous after a hiatus mixed terrigenous carbonate gravity flows accumulated in deep water during the late cretaceous the vardar ocean opened during the late triassic early jurassic separating the korabi pelagonian and serbo macedonian continents northeastward subduction created a late jurassic magmatic arc along the southern margin of the serbo macedonian continent while future ophiolites formed by supra subduction zone spreading within the vardar ocean these ophiolites were emplaced in response to collision of the subduction trench with the korabi pelagonian continent the pre mesozoic basement detached and subducted undergoing high pressure low temperature metamorphism during the late jurassic tithonian followed by amphibolite greenschist facies metamorphism and exhumation prior to the late cretaceous a much reduced vardar ocean survived into the late cretaceous until this finally closed during the latest cretaceous early cenozoic triggering continental collision and thick skinned folding thrusting of the pelagonian vardar and serbo macedonian zones towards the w sw

geochemistry tectonic setting and metamorphism of mid triassic volcanic rocks of greece abstract mid triassic volcanic rocks are preserved in about eight localities in the nappes of the external hellenides and are also widespread in the pelagonian zone of central greece most have suffered low grade metamorphism immobile trace elements from 35 samples 80 major element analyses and pyroxene analyses show that these rocks are the product of an eastward dipping subduction zone the subducted ocean was perhaps analogous to the pennine zone of the alps the othris and pindos ophiolites are probably contemporaneous products of related back arc extension metamorphic mineral assemblages in volcanic rocks of the phyllite series of the external hellenides indicate high pressure low temperature conditions probably related to a second subduction that occurred prior to the main phase of hellenide nappe emplacement in the miocene

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

westward propagation of the north anatolian fault into the northern aegean timing and kinematics we present new evidence for the propagation processes of the north anatolian fault folding in the dardanelles straits region allows us to document the timing of the deformation preceding and the finite displacement after the passage of the propagating tip of the fault the accuracy of the observations is due to interplay between deformation and the sea level changes in the mediterranean the well known messinian regression followed by the pliocene transgression the long term kinematics around the sea of marmara pull apart total displacement of about 85 km over the past 5 m y is similar to the present day kinematics deduced from space geodesy at a larger scale westward propagation of the north anatolian fault over nearly 2000 km in the past 10 m y appears to be associated with strain recovery suggesting that the continental lithosphere retains long term elasticity

eddy driven recirculation of atlantic water in fram strait eddy resolving regional ocean model results in conjunction with synthetic float trajectories and observations provide new insights into the recirculation of the atlantic water aw in fram strait that significantly impacts the redistribution of oceanic heat between the nordic seas and the arctic ocean the simulations confirm the existence of a cyclonic gyre around the molloy hole near 80 n suggesting that most of the aw within the west spitsbergen current recirculates there while colder aw recirculates in a westward mean flow south of 79 n that primarily relates to the eastern rim of the greenland sea gyre the fraction of waters recirculating in the northern branch roughly doubles during winter coinciding with a seasonal increase of eddy activity along the yermak plateau slope that also facilitates subduction of aw beneath the ice edge in this area

tectonic history of a segment of the pelagonian zone northeastern greece continental metamorphic rocks and ophiolitic bodies within the pelagonian zone of the hellenides in the livadi area northeastern greece show repeated periods of deformation that accompany thermal events of early cretaceous and possibly late eocene age structures associated with the earlier deformation indicate thrusting towards the northeast accompanying regional metamorphism of upper greenschist to lower amphibolite facies later structures and a retrogression to lower greenschist facies associated with emplacement of the livadi ophiolitic rocks into their present position are likewise attributed to northeast directed thrusting and probably accompanied the allochthonous movement of the pelagonian basement over the mesozoic platform carbonates of mt olympos emplacement vectors of northeast polarity are inconsistent with tectonic models of the hellenides involving large scale southwestward obduction of mesozoic ophiolites from a single ocean located northeast of the pelagonian zone tectonic models inv

high frequency variability in the circulation and hydrography of the denmark strait overflow from a high resolution numerical model abstractinitial results are presented from a yearlong high resolution 2 km numerical simulation covering the east greenland shelf and the iceland and irminger seas the model hydrography and circulation in the vicinity of denmark strait show good agreement with available observational datasets this study focuses on the variability of the denmark strait overflow dso by detecting and characterizing boluses and pulses which are the two dominant mesoscale features in the strait the authors estimate that the yearly mean southward volume flux of the dso is about 30 greater in the presence of boluses and pulses on average boluses pulses are 57 1 27 5 h long occur every 3 2 5 5 days and are more frequent during the summer winter boluses pulses increase decrease the overflow cross sectional area and temperatures around the overflow interface are colder warmer by about 2 6 c 1 8 c the lateral extent of the boluses is much greater than that of the pulses in both cases the along stra

40ar 39ar laserprobe direct dating of discrete deformational events a continuous record of early alpine tectonics in the pelagonian zone nw aegean area greece abstract the pelagonian zone of the hellenides which occurs in the northwestern aegean region of the eastern mediterranean contains remnants of a high pressure metamorphic belt which subsequently underwent localized reworking during low temperature deformational events formation of alpine deformational structures in the ossa massif northern pelagonian zone occurred at metamorphic temperatures which failed to reset most pre alpine 40ar 39ar cooling ages in muscovite porphyroclasts the low metamorphic temperatures at alpine times have preserved the argon isotopic signature in white mica bearing deformational structures which allows direct dating of these structures and refinement of the alpine tectonic history in the region after separation of carefully selected and characterized mica generations application of sensitive 40ar 39ar laserprobe dating has resulted in a continuous record of the early alpine tectonic history of the ossa massif from the early cretaceous well into the eocene the early alpine history of the ossa massif records cooling of basement thrust slices which are mostly hercynian granites and metamorphics below ca 350 c by 100 ma while lower tectonostratigraphic levels of the basement had already cooled below these temperatures at around ca 285 ma blueschist facies mylonite fabrics related to a top to ene direction of tectonic transport yield ages as old as 84 5 3 3 ma exhumation of the blueschist facies sequences was initiated at ca 54 ma and involved tectonic activity along blueschist facies and greenschist facies mylonites zones final wsw ward transport of the metamorphic sequence across the structurally lowest and supposed autochthonous series occurred at around 45 ma and resulted in termination of the ductile deformation history in the studied area this study confines the onset of high pressure metamorphism in the pelagonian zone to an interval between 100 ma and 85 ma and has shown that high pressure metamorphism had terminated by ca 54 ma the recognition of an early to middle alpine cycle lasting over 30 million years and involving crustal shortening high pressure metamorphism exhumation and subsequent crustal shortening is a key contribution to a better understanding of the early alpine tectonic history of the aegean region and eastern mediterranean

geodynamic evolution of ophiolites from albania and greece dinaric hellenic belt one two or more oceanic basins all the geological constraints for an exhaustive reconstruction of the triassic to tertiary tectonic history of the southern dinaric hellenic belt can be found in albania and greece this article aims to schematically reconstruct this long tectonic evolution primarily based on a detailed analysis of the tectonic setting the stratigraphy the geochemistry and the age of the ophiolites in contrast to what was previously reported in the literature we propose a new subdivision on a regional scale of the ophiolite complexes cropping out in albania and greece this new subdivision includes six types of ophiolite occurrences each corresponding to different tectonic units derived from a single obducted sheet these units are represented by 1 sub ophiolite melange 2 triassic ocean floor ophiolites 3 metamorphic soles 4 jurassic fore arc ophiolites 5 jurassic intra oceanic arc ophiolites and 6 jurassic back arc basin ophiolites the overall features of these ophiolites are coherent with the existence of a single though composite oceanic basin located east of the adria pelagonian continental margin this oceanic basin was originated during the middle triassic and was subsequently early jurassic affected by an east dipping intra oceanic subduction this subduction was responsible for the birth of intra oceanic arc and back arc oceanic basins separated by a continental volcanic arc during the early to middle jurassic from the uppermost middle jurassic to the early cretaceous an obduction developed during which the ophiolites were thrust westwards firstly onto the neighboring oceanic lithosphere and then onto the adria margin

erratum to stratigraphy and tectonics of a time transgressive ophiolite obduction onto the eastern margin of the pelagonian platform from late bathonian until valanginian time exemplified in northern evvoia greece the obduction of an ophiolite sheet onto the eastern pelagonian carbonate platform complex of the hellenides began during the late bathonian and ended with the final emplacement of the ophiolite during valanginian time the early stages of obduction caused subaerial exposure of the platform recorded by an unconformity of callovian age which is marked by laterites overlying folded and faulted karstic substrates the laterites have distinct ophiolitic geochemical signatures indicating that emergent ophiolite had been undergoing lateritic weathering this unconformity coincides with widespread western tethyan callovian gaps indicating that the obduction in the hellenides was probably related to far reaching plate tectonic processes resumed gravitational pull and rollback of the subducted oceanic leading edge of the temporarily exposed ophiolite platform drowning continued into tithonian valanginian time documented initially by reefal carbonates and then by below ccd carbonate free radiolarian cherts and shales subsequently siliciclastic turbidites which apparently originated from uplifted variscan basement were deposited together with and over the radiolarite as the ophiolite nappe sheet advanced the nappe substrate underwent tectonic deformations of varying intensity while polymictic melange and syntectonic sedimentary debris accreted beneath the ophiolite and at the nappe front the provenience of the ophiolite nappe complexes of northern evvoia most probably has to be looked for in the vardar ocean

quaternary evolution of the corinth rift and its implications for the late cenozoic evolution of the aegean summary we present geological and morphological observations at different scales to constrain rates of faulting and the distribution of deformation in the seismically active aegean region we focus first on the 130 km long corinth rift an asymmetric graben where a flight of terraces of marine origin are uplifted we show that the edges of the terraces lie in the footwall of the normal fault bounding the corinth rift and correspond to sea level highstands of laic pleistocene age using a detailed analysis of aerial and spot imagery supported by field observations we have mapped 10 terrace platforms and strandlines ranging in elevation from 10 to 400 m over distances of 2 to 20 km from the fault the elevation of the terraces inner edges was estimated at 172 sites with an error of 5m this data set contains a precise description of the uplift and flexure of 10 different palaeohorizontal lines with respect to the present sea level to date the deformation we correlate the corinth terraces with late pleistocene oxygen isotope stages of high sea level stands and with global sea level fluctuations using a thick elastic plate model consistent with our current understanding of the earthquake cycle and a boundary element technique we reproduce the geometry of the shorelines to constrain both mechanical parameters and the slip on the fault we show that the seismogenic layer behaves over the long term as if its elastic modulus were reduced by a factor of about 1000 all the terraces are fitted for fault slip increasing in proportion to terrace age and the component of regional uplift is found to be less than 0 3 mm yr 1 the best fits give a slip rate of 11 3 mm yr 1 on the main rift bounding fault over the last 350 kyr other geological and morphologic information allows us to estimate the total age of the main fault 1 ma and to examine the mechanical evolution of the corinth rift the minimum observed sediment thickness in the gulf places an extreme check on the results of the modelling and a lower bound on slip rate of 6 7 mm yr 1 40 per cent less than estimated with modelling even this slip rate is nearly 10 times higher than for comparable features in most of the aegean and elsewhere in the world at a larger scale the spacing and asymmetry of the rift systems in the aegean suggest strain localization in the upper mantle with slow extension starting 15 myr ago or earlier the more recent 1 myr rapid phase of rifting in corinth partly reactivated this earlier phase of extension the younger faulting in corinth appears to result from its present location in the inhomogeneous stress field process zone of the south westward propagating tip of the southern branch of the north anatolian fault we extend these relations to propose a mechanical model for the late cenozoic evolution of the aegean as the arabia europe collision progressed in eastern turkey it caused anatolia to move to the west and the north anatolian fault to propagate into the aegean where the early slow extension started to be modified about 5 ma ago the process of propagation dramatically increased the activity of some but not all of the earlier rifts the model we present is compatible with tectonic observations as well as with the seismicity the palaeomagnetic rotations and the displacement field now observed with gps and slr

phosphatic hardgrounds and stromatolites from the limestone shale boundary section at prossilion maastrichtian paleocene in the parnassus ghiona zone central greece abstract sedimentological analysis of the limestone shale boundary section upper maastrichtian upper paleocene at prossilion parnassus ghiona zone revealed that the upper maastrichtian sediments represent a shallowing pelagic sequence towards the top the sequence becomes highly condensed and owing to interruption of deposition at the cretaceous tertiary boundary culminates in a hardground through early lithification boring and mineralization of the substratum by phosphates and iron oxides several sedimentological features led us to assume that cementation lithification of the sediments took place in a shallow submergent to periodically emergent setting stratiform and columnar laminated phosphatic stromatolitic crusts have developed on the bored pavements during the late early paleocene trapping the pelagic sediments deposited phosphate is considered to be supplied to the sediment by a bacterially controlled precipitation from interstitially circulated solutions both the uppermost maastrichtian layers and stromatolitic crusts are cross cut by a system of thin slightly sinuous sheaths or tubular structures interpreted as calcified filaments or rhizolitic structures this fact suggests prolonged subaerial exposure as a result of which pedogenic alteration of the already lithified sediments began by progressive reorganization of the substrata by soil forming processes crusts of cryptocrystalline phosphate formed corresponding to phoscrete formations

jurassic subduction zone tectonics of the rhodope massif in the thrace region ne greece as revealed by new u pb and 40ar 39ar geochronology of the evros ophiolite and high grade basement rocks abstract in the thrace region of ne greece the crystallization and post solidification cooling below 600 c of the intrusive suite of the circum rhodope belt arc related evros ophiolite span from 176 4 0 93 to 163 5 3 85 ma in the underlying rhodope high grade metamorphic basement ultra high pressure metamafic rocks are cross cut by orthogneisses with granitoid protoliths and crystallization ages between 160 0 69 and 154 1 5 ma this new u pb la icp ms zircon geochronological data provides evidence that the timing of the evolution of the evros ophiolite coincides within analytical error with granitoid magmatism in the underlying high grade basement one of the dated metagranitoid rocks cross cuts amphibolitized eclogite indicating that the high pressure conditions have a maximum age of 160 ma postdating one of the proposed ages of ultra high pressure conditions in the rhodope massif the currently earliest recognised rhodope high ultra high pressure metamorphic event is therefore related to the subduction setting which formed the evros ophiolite based on these new temporal constraints and the regional tectonic geochronologic framework we discuss and update the geodynamic context connected to the jurassic subduction collisional setting at the rhodope continental margin of eurasia

kinematics and ophiolite obduction in the gerania and helicon mountains central greece abstract new structural petrofabric and palaeostress data from the beotia area central greece were used to investigate the tectonic evolution of the suture zone between the external parnassus microplate and internal hellenides pelagonian microplate petrofabric studies of ultramafic rocks were done using conventional u stage analysis and the electron backscatter diffraction ebsd technique detailed structural analysis enabled us to distinguish three main deformation phases that took place from the triassic to the eocene triassic jurassic deformation is related to continental rifting and the progressive formation of an ocean basin ophiolites formed above a westward dipping supra subduction zone ssz in the early late jurassic trench margin collision resulted in the southeastward emplacement of the ophiolite nappe over the pelagonian margin there is also evidence for a north westward thrusting of ophiolitic rocks over the gerania and helicon units during berriasian time this latter tectonic process is closely related to the deposition of beotian flysch into a foreland basin an extensional phase of deformation accompanied by shallow water carbonate sedimentation is documented in the upper cretaceous later during paleocene the area was subjected to a compressional deformation phase characterised by sw directed thrusting and folding as well as ne verging backthrusts and backfolds our proposed geotectonic model suggests the consumption of the ocean between the parnassus and pelagonian microplates this model includes late jurassic eastward ophiolite obduction followed by early cretaceous west directed ophiolite thrusting

geochemistry and petrogenesis of archaean metavolcanic amphibolites from fiskenaesset s w greenland abstract the meta volcanic amphibolites closely associated with the fiskenaesset anorthosite complex can be subdivided on the basis of trace element patterns or mineral chemistry by far the most abundant type has light rare earth element lree depleted ree patterns and displays a wide range in trace element abundances chemically comparable amphibolites can be recognised throughout the ca 2800 m yr west greenland terrain the geochemistry of the basaltic amphibolites is dominantly controlled by fractional crystallisation processes although variable degrees of partial melting may also be important the required crystal extract plagioclase dominated in the proposed fractionation scheme is very similar to the primary mineralogy of cumulates of the fiskenaesset complex and trace element models support a genetic relationship between the anorthosite complex and enclosing host amphibolites the application of trace element discrimination to assign tectonic environment in the archaean is arguable however details of the trace element chemistry especially chondritic la ta ratios are taken to suggest out of a range of likely tectonic environments an ocean floor rather than island arc affinity for the fiskenaesset amphibolites the large ion lithophile lil elements display erratic distribution patterns but are generally enriched relative to the ree this appears not to be related to high grade metamorphism but may be a relict feature of seafloor alteration the association of the cumulate sequence with meta volcanic amphibolites and metasediments probably represents an ocean floor assemblage emplaced into the lower crust during crustal accretion

timing of tectonic emplacement of the ophiolites and terrane paleogeography in the hellenides the timing of tectonic emplacement of the ophiolites is analyzed in the four oceanic terranes of the hellenides h2 h4 h6 h8 the criteria for this analysis are based on a the post emplacement sedimentary cover or intrusive rocks b the syn emplacement tectonostratigraphic formations and c the youngest rocks involved in the structure of the autochthon and the allochthon unit in each case the timing becomes younger towards the more external tectonic units of the hellenides with i late eocene oligocene age in the external ophiolite belt of the pindos cyclades oceanic terrane h2 ii late jurassic early cretaceous age in the internal ophiolite belt of the vardar axios oceanic terrane h4 iii post liassic pre late jurassic age in the ophiolites of lesvos circum rhodope oceanic terrane h6 and iv pre late jurassic age in the ophiolites of volvi eastern rhodope terrane h8 an ophiolite obduction model can be applied with the ophiolitic nappes always emplaced on top of pre alpine continental terranes with mesozoic shallow water carbonate platforms the geometry of the continental terranes drifting during the mesozoic within the tethys ocean controls the number and dimensions of the tethyan oceanic basins where a continental terrane dies out the two adjacent oceanic basins merge into one larger basin this seems to be the case of the pelagonian terrane h3 which is terminated north of skopje where the pindos oceanic basin h2 merges with the vardar axios oceanic basin h4

the pindos fold and thrust belt greece inversion kinematics of a passive continental margin continuous exposure in the pindos mountain chain greece and the detailed stratigraphic measurements in the area enable us to construct eight balanced cross sections across the pindos fold and thrust belt pftb and to approach quantitatively some parameters which controlled foreland evolution the 160 km wide passive continental margin of the apulian continent in greece was progressively shortened from east to west at rates of 6 mm year between the early oligocene and late eocene from the rear to the frontal part of the wedge fault bend folds duplexes and imbricates were formed while strain was partitioned into faulting 34 layer parallel shortening 23 and buckling 9 foreland subsidence and internal deformation of the orogenic wedge are strongly affected by two parameters of equal importance the thrust load of the overthrusted microcontinents and the rigidity of the underthrusted apulian passive margin changes in the thickness of the pre orogenic sediments and reactivated transform faults induced salients during the lower miocene the orogenic wedge in the peloponnese suffered additional uplift and westward gravitational gliding induced by the intracontinental subduction of the palaeozoic rift zone of the phyllite quartzite series which was reactivated and returned to the earth s surface during the hellenic orogeny

significant role of the north icelandic jet in the formation of denmark strait overflow water the largest dense water plume feeding the lower limb of the atlantic meridional overturning circulation from the nordic seas comes from denmark strait overflow water measurements of hydrography and water velocity north of iceland and ocean model simulations indicate that a significant part of this water is supplied by the north icelandic jet

the impact of calcareous nannofossils on the pelagic carbonate accumulation across the jurassic cretaceous boundary abstract calcareous nannofossils were important producers of pelagic carbonates in mesozoic oceans in order to better understand the origin of mesozoic pelagic carbonates we studied upper jurassic to lower cretaceous sediments in the central atlantic ocean dsdp sites 105 367 534a with respect to their content of calcareous nannofossils the interval under investigation is characterized by a significant increase in the deposition of carbonate rich sediments a trend that goes along with the rapid radiation of calcareous nannofossils the assemblage composition and the size variation of common taxa were analyzed and subsequently the contribution of this phytoplankton group to the pelagic carbonate accumulation was calculated results reveal two long term changes of the nannofossil assemblage composition 1 the early tithonian coccolith assemblages are of low diversity watznaueria spp cyclagelosphaera spp zeugrhabdotus spp whilst the mid to late tithonian assemblage is dominated by nannoliths conusphaera mexicana polycostella beckmannii nannoconus spp and large sized watznaueria 2 the early berriasian is characterized by a shift from the late tithonian nannolith rich assemblage to a highly diverse coccolith assemblage morphometric studies of the placolith genus watznaueria show for all three dsdp sites large sized forms of this genus in the mid and late tithonian followed by a decrease of up to 2 m for the mean size in the earliest berriasian at dsdp site 105 the studied nannolith taxa show an increase in size during the mid tithonian to berriasian interval the records of both nannofossil carbonate estimates and the measured bulk rock carbonate reveal two periods of increase in the nannofossil carbonate record of dsdp site 105 a first significant increase of the carbonate accumulation is observed in the mid and late tithonian probably caused by mass occurrences of strongly calcified taxa c mexicana p beckmannii nannoconus spp watznaueria cf manivitae this interval is here named nannofossil calcification event nce the second carbonate maximum in the late berriasian is related to a rise in absolute abundances of nannofossils this peak is amplified by an overall increase of the sedimentation rate the calculated accumulation rates of nannofossils nannofossil carbonate and bulk rock carbonate for the late berriasian are on the same scale as values from recent ocean surface sediments a comparison of nannofossil carbonate values with the bulk rock carbonate content shows that on average only 27 of the total carbonate can be explained by our nannofossil carbonate estimates this discrepancy is most likely caused by the high amount of unidentifiable micrite and fragments of calcareous nannofossils other factors contributing to the error are possible inaccuracies in the determination of absolute abundances and nannofossil volume calculations the nce occurs during a long term sea level fall dry climate and presumed low pco 2 levels a decline in abundance of strongly calcified nannofossils coincides with the opening of the pacific atlantic seaway via central america which may have had a substantial impact on the palaeoceanographic situation in the central atlantic ocean these changes are here considered to have at least partly caused the shifts in abundance size and assemblage composition of calcareous nannofossils observed across the jurassic cretaceous boundary interval

age and tectonomagmatic setting of the eocene copler kabatas magmatic complex and porphyry epithermal au deposit east central anatolia turkey the copler epithermal au deposit and related subeconomic porphyry cu au deposit is hosted by the middle eocene copler kabatas magmatic complex in central eastern anatolia the intrusive rocks of the complex were emplaced into late paleozoic mesozoic metamorphosed sedimentary basement rocks near the northeastern margin of the tauride anatolide block igneous biotite from two samples of the magmatic complex yielded 40ar 39ar plateau ages of 43 75 0 26 ma and 44 19 0 23 whereas igneous hornblende from a third sample yielded a plateau age of 44 13 0 38 these ages closely overlap with 40ar 39ar ages of hydrothermal sericite 44 44 0 28 ma and biotite 43 84 0 26 ma and re os ages from two molybdenite samples 44 6 0 2 and 43 9 0 2 ma suggesting a short lived 1 my magmatic and hydrothermal history at copler no suitable minerals were found that could be used to date the epithermal system but it is inferred to be close in age to the precursor porphyry system the copler kabatas intrusive rocks show i type calc alkaline affinities their normalized trace element patterns show enrichments in large ion lithophile and light rare earth elements and relative depletions in middle and heavy rare earth elements resembling magmas generated in convergent margins however given its distance from the coeval eocene maden helete volcanic arc the complex is interpreted to be formed in a back arc setting in response to paleocene slab roll back and upper plate extension the tectonomagmatic environment of porphyry epithermal mineralization at copler is comparable to some other isolated back arc porphyry systems such as bajo de la alumbrera argentina or bingham canyon usa

frontogenesis and variability in denmark strait and its influence on overflow water abstracta high resolution numerical model together with in situ and satellite observations is used to explore the nature and dynamics of the dominant high frequency from one day to one week var

late cretaceous intra oceanic magmatism in the internal dinarides northern bosnia and herzegovina implications for the collision of the adriatic and european plates abstract the kozara mountains of northern bosnia and hercegovina form part of the internal dinarides and host two tectonically juxtaposed ophiolitic successions of different age the southern part of the kozara mountains exposes the western vardar ophiolitic unit which was obducted onto the adriatic margin in the late jurassic the northern part exposes a bimodal igneous succession that was thrust onto the western vardar ophiolitic unit during the latest cretaceous to early paleogene this bimodal igneous succession comprises isotropic gabbros doleritic dikes basaltic pillow lavas and rhyolites pelagic limestones intercalated with pillow lavas yielded a campanian globotruncanid association consistent with concordant u pb ages on zircons from dolerites and rhyolites of 81 39 0 11 and 81 6 0 12 ma respectively chondrite normalised rare earth element patterns of the bimodal igneous rocks show enrichment of lree over hree primitive mantle normalised multi element diagrams do not reveal significant depletion of hfse the end t and initial 87sr 86sr isotopic values range from 4 4 to 6 3 and from 0 70346 to 0 70507 respectively suggesting an intraoceanic origin the bimodal igneous succession is unconformably overlain by maastrichtian to paleocene siliciclastics that contain abundant ophiolitic detritus suggesting reworking of the campanian magmatics an eocene turbiditic sandstone succession unconformably covers both the western vardar ophiolitic unit and the late cretaceous bimodal igneous successions these observations suggest that the adriatic plate and the europe derived tisza and dacia mega units were still separated by a deep basin floored by oceanic lithosphere until the campanian and that its closure did not occur before the maastrichtian to earliest paleogene this late cretaceous oceanic domain probably represented a remnant of the vardar ocean or alternatively the alpine tethys possibly the traces of both oceanic domains were connected in the area

neotethyan evolution of eastern greece pagondas melange evia island inferred from radiolarian biostratigraphy and the geochemistry of associated extrusive rocks this paper presents new radiolarian biostratigraphic and igneous metamorphic geochemical data for a mesozoic volcanic sedimentary melange on the island of evia euboea or evvoia eastern greece this melange includes dismembered thrust sheets and blocks of radiolarian chert and basalt biostratigraphic age data show that radiolarites interbedded with basalt derived coarse clastic sediments near the base of a coherent succession were deposited in middle and late triassic time late ladinian carnian norian geochemical evidence shows that associated extrusive rocks of inferred triassic age range from enriched alkaline basalts to transitional basalts and more depleted mid ocean ridge type basalts amphibolite facies meta basalts from the metamorphic sole of the over riding evia ophiolite exhibit similar chemical compositions both the basalts and the meta basalts commonly show an apparent subduction related influence e g relative nb depletion that may have been inherited from a previous subduction event in the region the basalts are interpreted to have erupted during middle late triassic time late ladinian carnian related to initial opening of a neotethyan ocean basin adjacent to a rifted continental margin radiolarites located stratigraphically higher in the coherent succession studied are dated as middle jurassic late bathonian early callovian similar aged radiolarites are depositionally associated with ophiolitic rocks including boninites in some other areas of greece and albania during initial ocean basin closure bajocian bathonian the adjacent shallow water carbonate platform pelagonian zone disintegrated to form basins in which siliceous sediments were deposited and highs on which shallow water carbonates continued to accumulate this facies differentiation is seen as a response to crustal flexure as the neotethyan ocean began to close the over riding pagondas melange and other similar units in the region are interpreted as accretionary prisms related to subduction of neotethyan oceanic crust in middle late jurassic time these melanges were emplaced probably diachronously during oxfordian kimmeridgian time when the passive margin collapsed creating a foredeep ahead of advancing thrust sheets of melange and ophiolites

structure and variability of the denmark strait overflow model and observations we report on a combined modeling and observational effort to understand the denmark strait overflow dso four cruises over the course of 3 years mapped hydrographic properties and velocity fields with high spatial resolution the observations reveal the mean path of the dense water as well as the presence of strong barotropic flows energetic variability and strong bottom friction and entrainment a regional sigma coordinate numerical model of interbasin exchange using realistic bottom topography and an overflow forced only by an upstream reservoir of dense fluid is compared with the observations and used to further investigate these processes the model successfully reproduces the volume transport of dense water at the sill as well as the 1000 m descent of the dense water in the first 200 km from the sill and the intense eddies generated at 1 3 day intervals hydraulic control of the mean flow is indicated by a region supercritical to long gravity waves in the dense layer located approximately 100 km downstream of the sill in both model and observations in addition despite the differences in surface forcing both model and observations exhibit similar transitions from mostly barotropic flow at the sill to a bottom trapped baroclinic flow downstream indicating the dominant role of the overflow in determining the full water column dynamics

on the nature of the mesoscale variability in denmark strait abstracttime series data from a mooring in the center of denmark strait and a collection of shipboard hydrographic sections occupied across the sill are used to elucidate the mesoscale variability of the dense overflow water in the strait two dominant reoccurring features are identified that are referred to as a bolus and a pulse a bolus is a large weakly stratified lens of overflow water associated with cyclonic rotation and a modest increase in along stream speed of 0 1 m s 1 when a bolus passes through the strait the interface height of the overflow layer increases by 60 m and the bottom temperature decreases by 0 4 c by contrast a pulse is characterized by anticyclonic rotation a strong increase in along stream speed of 0 25 m s 1 a decrease in interface height of 90 m and no significant bottom temperature signal it is estimated that on average boluses pulses pass through the strait every 3 4 5 4 days with no seasonal signal to their frequency both features have the strongest along

distribution of porphyry copper deposits along the western tethyan and andean subduction zones insights from a paleotectonic approach abstract along the western tethyan and andean subduction zones the distribution of cretaceous and cenozoic porphyry cu deposits is not random and shows that they were emplaced in distinct regional clusters to understand the appearance of these clusters within their geodynamical contexts and identify kinematic features which would favor the genesis of porphyry type ore bodies we use a paleotectonic approach two clusters in the aegean balkan carpathian area which were emplaced in upper cretaceous and oligo miocene and two others in the andes which were emplaced in late eocene and miocene are sufficiently well constrained to be studied in detail it appears that they are associated with a specific polyphased kinematic context related to the convergence of tectonic plates this context is characterized by 1 a relatively fast convergence rate shortly followed by 2 a drastic decrease of this rate from these observations and assuming that the major part of plate convergence is accommodated along subduction zones we propose a two phase geodynamic model favoring emplacement of porphyry cu deposits 1 a high melt production in the mantle wedge followed by 2 an extensional regime or at least relaxation of the compressional stress in the upper plate promoting ascension of fertile magmas to the upper crust melt production at depth and the following extensional regime which would be related to variations in convergence rate are thus associated with variations in plate and trench velocities themselves being controlled by both plate kinematics at the surface and slab dynamics in the upper mantle in particular along strike folding behavior of the subducting slab may strongly influence trench velocity changes and the location of porphyry cu deposits metallogenic data suggest that periods of slab retreat which would favor mineralization processes during 40 myrs would be separated by barren periods lasting 10 to 20 myrs corresponding to shorter episodes of trench advance as observed in laboratory experiments these results confirm the control of the geodynamic context and especially subduction dynamics on the genesis of porphyry cu deposits this study also shows that the paleotectonic approach is a promising tool that could help identify geodynamic and tectonic criteria favoring the genesis of various ore deposits

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

tectonic configuration of the apuseni banat timok srednogorie belt balkans south carpathians constrained by high precision r e o s molybdenite ages the apuseni banat timok srednogorie magmatic metallogenic belt abts belt forms a substantial metallogenic province in the balkan south carpathian system in southeastern europe the belt hosts porphyry skarn and epithermal deposits mined since pre roman times generally the deposits prospects and occurrences within the belt are linked to magmatic centers of calc alkaline affinity fifty one rhenium osmium re os ages and re concentration data for molybdenites define systematic geochronologic trends and constrain the geochemical metallogenic evolution of the belt in space and time from these data and additional existing geologic geochemical data a general tectonic history for the belt is proposed mineralization ages in apuseni banat timok and panagyurishte the central district of the larger e w srednogorie zone range from 72 83 81 88 and 87 92 ma respectively and clearly document increasing age from the northwestern districts to the southeastern districts further re os ages suggest rapidly migrating pulses of late cretaceous magmatic hydrothermal activity with construction of deposits in 1 m y districts in 10 m y and the entire 1 500 km belt in 20 m y ages in both timok and panagyurishte show systematic younging while deposit ages in banat and apuseni are less systematic reflecting a restricted evolution of the tectonic system systematic differences are also observed for molybdenite re concentrations on the belt scale re concentrations generally range from hundreds to thousands of parts per million typical of subduction related cu au mo pge porphyry systems associated with the generation of juvenile crust the geochronologic and geochemical trends are compatible with proposed steepening of subducting oceanic slab and relaxation of upper continental plate compression resulting influx of sub continental mantle lithosphere scml and asthenosphere provide a fertile metal source and heat while the subducting slab contributes connate and mineral dehydration fluids which facilitate partial melting and metal leaching of scml and asthenosphere cu au mo pge porphyry deposits may develop where melts are trapped at shallow crustal levels often with associated volcanism and epithermal style deposits south banat timok and panagyurishte mo fe pb zn skarn deposits may develop where felsic melts are trapped adjacent to mesozoic limestones at moderate crustal levels north banat and apuseni systematic spatial variations in deposit style commodity enrichment re os ages and re concentrations support specific tectonic processes that led to ore formation in a post collisional setting subduction of vardar oceanic crust may have stalled causing slab steepening and rollback the slab rollback relaxes compression facilitating and enhancing orogenic collapse of previously thickened balkan south carpathian crust the progression of coupled rollback orogenic collapse is evidenced by the width of late cretaceous extensional basins and northward younging of re os ages from panagyurishte 60 km 92 87 ma to timok 20 km 88 81 ma to apuseni banat 5 km 83 72 ma generation of a well endowed mineral belt such as the abts requires a temporally and spatially restricted window of magmatic hydrothermal activity this window is quickly opened as upper plate compression relaxes thereby inducing melt generation and ingress of melt to higher crustal levels the window is just as quickly closed as upper plate compression is reinstated the transient tectonic state responsible for economic mineralization in the abts belt may be a paleo analogue to transient intervals in the present subduction tectonics of se asia where much mineral wealth has been created in the last few million years

age and significance of upper cretaceous siliciclastic turbidites in the central pindos mountains greece a significant 5 to 30 metre thick interval of siliciclastic turbidites forming the first flysch is present in the deep water succession of the pindos zone nannofossil investigations in the central parts of the pindos mountains of mainland greece indicate an assemblage of the marthasterites furcatus zone cc13 the presence of m furcatus together with common quadrum gartneri suggests that the turbidites were deposited mainly during the middle to upper part of the late turonian the siliciclastic turbidites are interpreted as deposits of a lowstand fan as a result of a pronounced short time eustatic sea level drop in the late turonian

sedimentary geology as a key to understanding the tectonic evolution of the mesozoic early tertiary paikon massif vardar suture zone n greece abstract this paper demonstrates how sedimentary evidence can provide a key to elucidating the regional tectonic and palaeoceanographic significance of a complex partly metamorphic terrane in this case the paikon massif the paikon massif is located centrally within the vardar axios zone of n greece and is critical to the reconstruction of neotethys in the e mediterranean region the massif is here restored as a single tectono stratigraphic unit of jurassic to early tertiary age that originated along the margin of a continental unit known as the serbo macedonian zone in this area a mesozoic oceanic basin the almopias ocean opened in the triassic between the serbo macedonian continent to the ne and another continental unit the pelagonian zone to the sw initial deep water deposition along the northwesterly passive margin of the almopias ocean is represented within the paikon massif by metamorphosed redeposited carbonates and hemipelagic sediments gandatch formation above this the jurassic paikon volcanic group comprises two volcanogenic units of island arc type livadia and kastaneri formations the arc developed along the sw margin of the serbo macedonian continent in response to ne subduction of the almopias ocean the subduction also resulted in the opening of a related back arc basin in mid late jurassic represented by the guevgueli ophiolite now to the ne of the paikon massif the massif underwent ductile deformation and inferred hp lt metamorphism during late jurassic time related to subduction beneath the serbo macedonian active margin exhumation took place rapidly by kimmeridgian time followed by a shallow water transgression khromni limestones subsequent emergence and fluvial deposition ghrammos formation reflect a regional extensional or transtensional event following a marine transgression influenced by eustatic sea level rise and tectonic subsidence aptian albian a carbonate platform developed throughout the paikon massif cretaceous transgressive limestones short lived emergence turonian was followed by deepening in the campanian maastrichtian and pelagic carbonate deposition buff pelagic carbonates overlying terrigenous turbidites tchouka flysch form part of an early tertiary foredeep in a regional contractional setting late stage shortening resulted in bivergent thrusting and folding to form the paikon massif as a large anticlinal pop up structure near the axis of the suture zone localised transpression and neotectonic extension complete the picture

mesoscale variability in denmark strait the pv outflow hypothesis abstract the outflow through denmark strait shows remarkable mesoscale variability characterized by the continuous formation of intense mesoscale cyclones just south of the sill these cyclones have a diameter of about 30 km and clear signatures at the sea surface and in currents measured near the bottom they have a remnant of arctic intermediate water aiw in their core the authors hypothesis is that these cyclones are formed by stretching of the high potential vorticity pv water column that outflows through denmark strait the light upper layer of the outflow the east greenland current remains on the surface in the irminger sea while the dense overflow water descends the east greenland continental slope the midlevel waters mostly aiw could thus be stretched by more than 100 which would induce very strong cyclonic relative vorticity the main test of this new hypothesis is by way of numerical experiments carried out with an isopycnal coordinate ocean model configured to have a marginal sea

the emergence of the north icelandic jet and its evolution from northeast iceland to denmark strait abstractthe north icelandic jet nij is an important source of dense water to the overflow plume passing through denmark strait the properties structure and transport of the nij are investigate

mesozoic early tertiary passive margin evolution of the pindos ocean nw peloponnese greece abstract sediment starved deep water slope basin facies of passive margins are of particular interest as they record an interplay of processes including plate tectonic evolution elastic sediment input pelagic deposition and relative sea level change in the past insights have come from deep sea drilling of non emplaced passive margins e g eastern u s a and from preserved sequences within sutured units e g the tethyan and iapetus orogenic belts deep water passive margin successions discussed here represent an excellent example of a relatively sediment starved slope basin setting related to the margin of a microcontinent within the neotethyan ocean in the eastern mediterranean region lithologies are preserved as a series of thrust sheets formed during suturing of the neotethys ocean thrusting resulted in regular in sequence thrusting such that the original slope margin setting can be restored with confidence compared to other tethyan passive continental margin abyssal successions e g oman these sedimentary rocks retain remarkable structural coherence allowing exceptionally detailed three dimensional reconstructions of facies patterns and palaeoceanographic conditions the sedimentary successions belong to the pindos zone of western greece pindos group and comprise deep water carbonate siliciclastic and siliceous rocks ranging in age from late triassic to eocene these rocks accumulated along the western margin of a small neotethyan oceanic basin i e pindos ocean separating the continental blocks of adria apulia and pelagonia the oldest sediments comprise disrupted siliciclastic turbidites largely derived from a metamorphic source to the west and deposited on young oceanic basement from the late triassic to latest maastrichtian variable thicknesses of hemipelagic carbonate and proximal carbonate debris flows accumulated in westerly areas while mainly hemipelagic carbonate and more distal calciturbidite were deposited further east this pattern was interrupted by an extended period of siliceous radiolarian dominated sedimentation during the aalenian to tithonian jurassic from latest maastrichtian onwards progressive closure of the pindos oceanic basin is recorded by a gradual change in sediment composition from dominantly carbonate deposition supplied from the gavrovo tripolitza carbonate platform to the west to siliciclastic sediment derived from the north and east during the eocene oligocene eastward subduction of the pindos ocean resulted in deep sea sedimentary lithologies being detached from their oceanic igneous basement as an accretionary prism and emplaced westwards onto the adjacent carbonate platform ending up as a series of thin skinned thrust sheets

lagrangian perspective on the origins of denmark strait overflow the denmark strait overflow dso is an important contributor to the lower limb of the atlantic meridional overturning circulation amoc determining dso formation and its pathways is not only important for local oceanography but also critical to estimating the state and variability of the amoc despite prior attempts to understand the dso sources its upstream pathways and circulation remain uncertain due to short term 3 5 days variability this makes it challenging to study the dso from observations given this complexity this study maps the upstream pathways and along pathway changes in its water properties using lagrangian backtracking of the dso sources in a realistic numerical ocean simulation the lagrangian pathways confirm that several branches contribute to the dso from the north such as the east greenland current egc the separated egc segc and the north icelandic jet nij moreover the model results reveal additional pathways from south of iceland which supplied over 16 of the dso annually and over 25 of the dso during winter of 2008 when the nao index was positive the southern contribution is about 34 by the end of march the southern pathways mark a more direct route from the near surface subpolar north atlantic to the north atlantic deep water nadw and needs to be explored further with in situ observations

3 geochronology and geodynamics of late cretaceous magmatism and cu au mineralization in the panagyurishte region of the apuseni banat timok srednogorie belt bulgaria abstract the apuseni banat timok srednogorie abts belt europe s most extensive belt of calc alkaline magmatism and cu au mineralization is related to the subduction of the tethys ocean beneath the european continental margin during the late cretaceous phase of the alpine himalayan orogeny economic deposits are restricted to certain segments along the belt and all major porphyry style and high sulphidation ore deposits in bulgaria are aligned on the panagyurishte corridor a narrow zone obliquely crossing the abts belt this paper reviews the geology geochemistry and geochronology of igneous and hydrothermal events along this corridor in a profile extending from the european continental basement in the north to the accretionary complex of the rhodopes in the south extensive u pb dating of zircons from subvolcanic intrusions and major plutons supplemented by published age data for magmatic rocks and hydrothermal ore deposits obtained by other methods reveals a general younging of magmatism from ca 92 ma in the north elatsite to ca 78 ma in the south capitan dimitrievo cu au deposits are restricted to the northern and central parts of the profile ranging in age from 92 to 86 ma while the southernmost part exposes more deeply eroded mid crustal plutons devoid of economic mineralization the age progression correlates with a north to south geochemical trend of decreasing crustal input into mantle derived magmas magmatism and ore formation in individual magmatic hydrothermal complexes along the profile is much shorter lived for example subvolcanic intrusions and porphyry cu au mineralization at the elatsite deposit and andesitic volcanism and high sulphidation au as cu mineralization at chelopech all occurred within a time span of about 1 million years the age progression of calc alkaline magmatism within the panagyurishte region bulgaria from north to south is explained as a consequence of slab retreat during oblique subduction this led to transtensional block faulting and subsidence and thus to the preservation of near surface magmatic hydrothermal products including economic cu au deposits accretion of continental fragments in the rhodopes south of the abts belt led to greater uplift of the youngest late cretaceous intrusions this removed any ore deposits that might have been formed in this area

the production of north atlantic deep water sources rates and pathways updating an earlier account by dickson et al 1990 this paper reviews the initial development phase of north atlantic deep water nadw production from the points where the dense inflows from nordic seas cross the greenland scotland ridge to the point off south greenland where the buildup of new production appears almost complete in particular three long term current meter arrays totaling 91 instruments and set at 160 km intervals south from the denmark strait sill are used to validate earlier short term arrays by others and in combination with these earlier arrays to describe the downstream evolution of mean speed depth and entrainment the variability of the overflow current in space and time and the likely contribution of the other three main constituents of nadw production at densities greater than 27 8 from the points of overflow 5 6 sv the transport within this range increases by entrainment and confluence with other contributory streams to around 13 3 sv at cape farewell while recirculating elements prevent us from determining the net southgoing transport a nadw transport of this order appears consistent with recent estimates of net abyssal flow passing south through the north and south atlantic

metamorphic core complexes of cordilleran type in the cyclades aegean sea greece the islands of ios and naxos in the cycladic archipelago greece contain elongate domes over which a pervasive north to north northeast stretching lineation is warped these islands may be metamorphic core complexes of cordilleran type involving middle crustal rocks drawn upward and outward from underneath the sedimentary basins now 100 km to the south from ca 25 ma onward during uplift the crystalline rocks now exposed on the islands were deformed noncoaxially in the deeper levels of a major shallow dipping ductile shear zone this shear zone may have connected with low angle normal faults in its upper levels because it is probable that its later history involved the metamorphic complexes being dragged out from under a stretching and fracturing upper plate composed mainly of unmetamorphosed sedimentary and ophiolite suite rocks this model can be extended to explain the exhumation of the high pressure low temperature metamorphic rocks on crete which with the cyclades forms a distended paired metamorphic belt separated by an active sedimentary basin