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Central Anatolia exposes previously buried and metamorphosed, continent-derived rocks – the Kirsehir and Afyon zones – now covering an area of ∼300 × 400 km. So far, the exhumation history of these rocks has been poorly constrained. We show for the first time that the major, >120 km long, top-NE ‘Ivriz’ Detachment controlled the exhumation of the HP/LT metamorphic Afyon Zone in southern Central Anatolia. We date its activity at between the latest Cretaceous and early Eocene times. Combined with previously documented isolated extensional detachments found in the Kirsehir Block, our results suggest that a major province governed by extensional exhumation was active throughout Central Anatolia between ∼80 and ∼48 Ma. Although similar in dimension to the Aegean extensional province to the east, the Central Anatolian extensional province is considerably older and was controlled by a different extension direction. From this, we infer that the African slab(s) that subducted below Anatolia must have rolled back relative to the Aegean slab since at least the latest Cretaceous, suggesting that these regions were underlain by a segmented slab. Whether or not these early segments already corresponded to the modern Aegean, Antalya, and Cyprus slab segments remains open for debate, but slab segmentation must have occurred much earlier than previously thought.

Multichronometric analyses were performed on samples from a transect in the French-Italian Western Alps crossing nappes derived from the Briançonnais terrane and the Piemonte-Liguria Ocean, in an endeavour to date both high-pressure (HP) metamorphism and retrogression history. Twelve samples of white mica were analysed by 39Ar-40Ar stepwise heating, complemented by two samples from the Monte Rosa nappe 100 km to the NE and also attributed to the Briançonnais terrane. One Sm-Nd and three Lu-Hf garnet ages from eclogites were also obtained. White mica ages decrease from c. 300 Ma in the westernmost samples (Zone Houillère), reaching c. 300°C during Alpine metamorphism, to 6·45 atoms per formula unit increases eastward. Across the whole traverse, phengitic mica grown during HP metamorphism defines the D1 foliation. Syn-D2 mica is more Si-poor and associated with nappe stacking, exhumation, and hydrous retrogression under greenschist-facies conditions. Syn-D1 phengite is very often corroded, overgrown by, or intergrown with, syn-D2 muscovite. Most importantly, syn-D2 recrystallization is not limited to S2 schistosity domains; micrometre-scale chemical fingerprinting reveals muscovite pseudomorphs after phengite crystals, which could be mistaken for syn-D1 mica based on microstructural arguments alone. The Cl/K ratio in white mica is a useful discriminator, as D2 retrogression was associated with a less saline fluid than eclogitization. As petrology exerts the main control on the isotope record, constraining the petrological and microstructural framework is necessary to correctly interpret the geochronological data, described in both the present study and the literature. Our approach, which ties geochronology to detailed geochemical, petrological and microstructural investigations, identifies 47-48 Ma as the age of HP formation of syn-D1 mica along the studied transect and in the Monte Rosa area. Cretaceous apparent mica ages, which were proposed to date eclogitization by earlier studies based on conventional ‘thermochronology', are due to Ar inheritance in incompletely recrystallized detrital mica grains. The inferred age of the probably locally diachronous, greenschist-facies, low-Si, syn-D2 mica ranges from 39 to 43 Ma. Coexistence of D1 and D2 ages, and the constancy of non-reset D1 ages along the entire transect, provides strong evidence that the D1 white mica ages closely approximate formation ages. Volume diffusion of Ar in white mica (activation energy E = 250 kJ mol−1; pressure-adjusted diffusion coefficient D'0 < 0·03 cm2 s−1) has a subordinate effect on mineral ages compared with both prograde and retrograde recrystallization in most samples

The waning stage(s) of the Tethyan ocean(s) in the Balkans are not well understood. Controversy centres on the origin and life-span of the Cretaceous Sava Zone, which is allegedly a remnant of the last oceanic domain in the Balkan Peninsula, defining the youngest suture between Eurasia- and Adria-derived plates. In order to investigate to what extent Late-Cretaceous volcanism within the Sava Zone is consistent with this model we present new age data together with trace-element and Sr–Nd– Pb isotope data for the Klepa basaltic lavas from the central Balkan Peninsula. Our new geochemical data show marked differences between the Cretaceous Klepa basalts (Sava Zone) and the rocks of other volcanic sequences from the Jurassic ophiolites of the Balkans. The Klepa basalts mostly have Sr–Nd–Pb isotopic and trace-element signatures that resemble enriched within-plate basalts substantially different from Jurassic ophiolite basalts with MORB, BAB and IAV affinities. Traceelement modelling of the Klepa rocks indicates 2%–20% polybaric melting of a relatively homogeneously metasomatised mantle source that ranges in composition from garnet lherzolite to ilmenite+apatite bearing spinel–amphibole lherzolite. Thus, the residual mineralogy is characteristic of a continental rather than oceanic lithospheric mantle source, suggesting an intracontinental within-plate origin for the Klepa basalts. Two alternative geodynamic models are internally consistent with our new findings: (1) if the Sava Zone represents remnants of the youngest Neotethyan Ocean, magmatism along this zone would be situated within the forearc region and triggered by ridge subduction; (2) if the Sava Zone delimits a diffuse tectonic boundary between Adria and Europe which had already collided in the Late Jurassic, the Klepa basalts together with a number of other magmatic centres represent volcanism related to transtensional tectonics.

Raman microspectroscopy on carbonaceous material (RSCM) from the eastern Tauern Window indicates contrasting peak-temperature patterns in three different fabric domains, each of which underwent a poly-metamorphic orogenic evolution: Domain 1 in the northeastern Tauern Window preserves oceanic units (Glockner Nappe System, Matrei Zone) that attained peak temperatures (T-p) of 350-480 degrees C following Late Cretaceous to Palaeogene nappe stacking in an accretionary wedge. Domain 2 in the central Tauern Window experienced T-p of 500-535 degrees C that was attained either within an exhumed Palaeogene subduction channel or during Oligocene Barrovian-type thermal overprinting within the Alpine collisional orogen. Domain 3 in the Eastern Tauern Subdome has a peak-temperature pattern that resulted from Eo-Oligocene nappe stacking of continental units derived from the distal European margin. This pattern acquired its presently concentric pattern in Miocene time due to post-nappe doming and extensional shearing along the Katschberg Shear Zone System (KSZS). T-p values in the largest (Hochalm) dome range from 612 degrees C in its core to 440 degrees C at its rim. The maximum peak-temperature gradient (70 degrees Ckm(-1)) occurs along the eastern margin of this dome where mylonitic shearing of the Katschberg Normal Fault (KNF) significantly thinned the Subpenninic- and Penninic nappe pile, including the pre-existing peak-temperature gradient.

This study documents the Cenozoic to recent evolution of the Adria-Europe plate boundary zone, the Sava Zone, in the northern Dinarides. Late Cretaceous subduction of last remnants of Vardar oceanic lithosphere led to the formation of a suture, across which the upper plate Tisza-Dacia Mega-Unit (attached to Europe during the Early Cretaceous and therefore referred to as European Plate, for simplicity) was juxtaposed against the Adriaderived units of the Dinarides. The Dinarides reside in a lower plate position and include Vardar-derived ophiolites obducted in the Latest Jurassic. Late Cretaceous, largely siliciclastic sediments have been incorporated into an accretionary wedge that evolved during the initial stages of continent-continent collision. The structurally lowest parts of the presently exposed accretionary wedge underwent amphibolite grade metamorphism. Top-to-the-Sdirected senses of shear in mylonites and south-facing folding in low-grade phyllites are consistent with the assumption that the European plate overthrusted the Adriatic units. 39Ar/40Ar amphibole ages indicate cooling from peak metamorphic conditions at ca. 55 Ma. Plate convergence continued throughout the Paleogene and gave rise to foreland propagation, i.e. southwest-directed thrusting within the Dinarides. From the Late Oligocene onwards the Sava Zone underwent extension. Its early stages were accompanied by retrogression of peak-metamorphic mineral assemblages and footwall exhumation beneath a low-angle detachment. 39Ar/40Ar white mica cooling ages between 28 and 24 Ma date the initial stages of extensional unroofing. The low-angle detachment telescoped the metamorphic gradient, transposed an older metamorphic foliation and became in turn cut by late-stage brittle high-angle normal faults. S-type granitoids with 206Pb/238U zircon and 207Pb/235U monazite ages of 26.7 and 26.6 Ma were syn-tectonically emplaced and developed a solid-state foliation that formed under greenschist-facies conditions. Zircon and apatite fission track ages from both metamorphics and granitoids range between 21 and 14 Ma and indicate ongoing exhumation. Late-stage cooling is synchronous with the Ottnangian to Karpatian synrift phase of the Pannonian Basin. After the Pontian, the normal faults were inverted, creating the characteristic ‘inselberg’ morphology of the southwestern Pannonian Basin. At present, the area is governed by N-S compression and represents the seismically most active part of the Dinarides apart from the external-most thrusts in the Adriatic Sea.

The investigated HP/LT metasedimentary units of the Valaisan and adjacent European domains occupy a key position in the Alpine belt for understanding the transition from early subduction-related HP/LT metamorphism to collision-related Barrovian overprint and the evolution of mountain belts in general. The timing of high-pressure metamorphism, subsequent retrogression and following Barrow-type overprint was studied by 40Ar/39Ar dating of biotite and several white mica generations that are well characterized in terms of mineral chemistry, texture and associated mineral assemblages. Four distinct age populations of white mica record peak pressure conditions (42–40 Ma) and several stages of subsequent retrograde metamorphic evolution (36–25 Ma). Biotite isotopic analyses yield consistent apparent ages that cluster around 18–16 Ma for the Barrow-type thermal overprint. The recorded isotopic data reveal a significant time gap in the order of some 20 Ma between subduction-related HP/LT metamorphism and collision-related Barrovian overprint, supporting the notion of a polymetamorphic evolution associated with a bimodal P-T path.

The investigated HP/LT metasedimentary units of the Valaisan and adjacent European domains occupy a key position in the Alpine belt for understanding the transition from early subduction-related HP/LT metamorphism to collision-related Barrovian overprint and the evolution of mountain belts in general. The timing of high-pressure metamorphism, subsequent retrogression and following Barrow-type overprint was studied by Ar-40/Ar-39 dating of biotite and several white mica generations that are well characterized in terms of mineral chemistry, texture and associated mineral assemblages. Four distinct age populations of white mica record peak pressure conditions (42-40 Ma) and several stages of subsequent retrograde metamorphic evolution (36-25 Ma). Biotite isotopic analyses yield consistent apparent ages that cluster around 18-16 Ma for the Barrow-type thermal overprint. The recorded isotopic data reveal a significant time gap in the order of some 20 Ma between subduction-related HP/LT metamorphism and collision-related Barrovian overprint, supporting the notion of a polymetamorphic evolution associated with a bimodal P-T path.

The interplay between slab dynamics and intraplate stresses in postcollisional times creates large near-surface deformation, particularly in highly bent orogens with significant lateral variations in mechanical properties. This deformation is expressed through abnormal foredeep geometries and contrasting patterns of vertical movements. Intraplate folding is often the controlling mechanism, particularly when the orogenic belt is locked. The study of these tectonic processes in the SE Carpathians indicates a generalized subsidence period during latest MiocenePliocene times driven by the slab-pull and an intraplate folding due to an overall Quaternary inversion. The latter accommodates 5 km ESE-ward movement of this area with respect to the neighboring units, which creates complicated threedimensional deformation patterns potentially driven at a larger scale by the interaction between the Adriatic indentor and the entire Carpathians system. The lithospheric anisotropy inherited from the subduction times concentrates strain and induces large-scale deformation far away from the active plate margins. This anisotropy is dynamic because of deep mantle processes related to the subducted slab during postcollisional times, such as thermal reequilibration or increase in slab dip.

The internal Dinarides of Former Yugoslavia are characterised by the widespread occurrence of ophiolites. Having formed part of the Vardar ocean, they were obducted onto the distal passive margin of the Adriatic platform in the Late Jurassic. Later, they were incorporated into the Late Cretaceous to Palaeogene SW-verging nappe stack of the Dinarides, where they occupy a structurally high position today. While there is general consensus about the (Late Jurassic) age of obduction of these ophiolites, recent investigations in the northernmost Dinarides of Bosnia-Hercegovina have revealed the existence of a mafic rock suite of Upper Cretaceous age in a yet more internal (i.e. more northerly) position of the Dinarides’ nappe stack. This mafic rock suite, exposed in the northern part of the Kozara Mountains (termed N Kozara from here on), very likely belongs to the “ Sava Zone” , a Mid-Cretaceous to Early Palaeogene accretionary prism, volcanic arc and back-arc basin that underwent Early Tertiary metamorphism and that remained open until collision between the Dinarides and the northerly adjacent Tisza block in the Mid-Eocene. Whether or not the mafic rocks of N Kozara truly represent ophiolites that could be regarded as a Cretaceous remnant of the Vardar ocean, is yet very improperly understood. Solving these questions, however, will improve timing constraints on the final closure of this domain and the subsequent collision with the Tisza block. It is therefore the aim of this study (a) to comprehend the structural position of the Kozara ophiolites with respect to the “ classic” Dinaric ophiolites, obducted in the Late Jurassic, and the northerly adjacent units within the Sava Zone, (b) to characterise their geodynamic setting using their geochemical signatures and (c) to obtain radiometric ages of the mafic rocks and biostratigraphic ages of associated sediments. Going from S to N, the massif of Kozara reveals the following succession of WNW-ESE-trending units. In the S, serpentinised lherzolithes and gabbros sit on top of a presumably Jurassic mélange formation, containing limestone olistolithes of Triassic age. Dolerites are found to be intersected by albite-rich felsic rocks. A Sm-Nd-age, obtained from a well-preserved olivine cumulate gabbro, yielded an age of 158 ± ; ; 8 Ma. This ophiolitic succession itself is unconformably covered by Palaeocene/Eocene Discocyclinae-bearing shallow-water limestones and subordinately shales that post-date the age of obduction. The mafic rocks of N Kozara are separated from the ones in the S by a 5 to 7 km wide belt of siliciclastic flysch of presumably Late Cretaceous to Palaeogene age. The mafic rocks of N Kozara, overlying the flysch, consist of basalts, dolerites and gabbros. Ultramafics are absent. Occasionally, basalts exhibit pillow-lava textures and are intercalated with red, pelagic limestones containing Globotruncanae that indicate an Early Campanian age (or, alternatively, Late Campanian to Early Maastrichtian. Gabbros and dolerites frequently reveal the growth of secondary, green amphibole on the expense of clinopyroxene, rendering these lithologies unsuitable for Sm-Nd-dating. Moreover, the N Kozara mafics are often intersected by Na- and K-rich felsic dikes. Geochemical analyses of mafic rocks from S and N Kozara show differences in both their major and trace element concentrations. Gabbros from the S show Mg-contents typical of primitive MORB. Basalts, dolerites and gabbros from N Kozara, on the other hand, exhibit significantly lower Mg-contents and enrichment of incompatible elements like Ti and P, suggesting a more differentiated or enriched magma source. Chondrite-normalised REE concentrations of samples from S Kozara (particularly gabbros) reveal a strong depletion of LREE and lesser depletion of HREE. Samples from N Kozara, in contrast, show enrichment of LREE over HREE. These features suggest an N-type MORB origin of the S Kozara samples, whereas N Kozara samples are more characteristic of an island-arc or transitional MORB setting with a low degree of partial melting. There is evidence that the mafic rock suites of S and N Kozara have been juxtaposed tectonically. This is indicated by basaltic pebbles from the separating flysch belt, which clearly bear the geochemical signature of the overlying N Kozara mafics. In agreement with published data we therefore invoke the possibility that the N Kozara mafics could represent a Late Cretaceous to Early Palaeogene (?) remnant of the Vardar ocean, which was juxtaposed against the “ classical” Dinaric ophiolites (obducted in the Late Jurassic) during the final closure of an oceanic domain within the Sava Zone. Future work will include the U-Pb-dating of zircons from highly differentiated gabbros and dolerites of N Kozara, as well as Nd- and Sr-isotope measurements on samples from both S and N Kozara. While the former should yield the first radiometric ages of the N Kozara mafic suite, the latter will allow characterising its mantle reservoir. Moreover, fission track analyses will be carried out in order to constrain the cooling history.

This study addresses the polyphase Miocene tectonic evolution in the Maramures area (northern Romania) by combining field observations, stratigraphic arguments and fission-track analysis (Tischler et al. in press). Fission-track analysis has been carried out on basement samples from the Rodna horst, situated in the East Carpathians (Bucovinvian nappes). This area was affected by Cretaceous medium- to low-grade metamorphism, followed by post-collisional exhumation and renewed moderate thermal overprint due to the deposition of Eocene to Early Miocene sediments. Based on paleostress analyses of mesoscale structures, three main tectonic phases can be disdinguished in the study area, all of which are postdate the earliest Miocene (Aquitanian, 20.5 Ma). In late Early Miocene (Burdigalian) the Pienide nappes, nonmetamorphic flysch series, were emplaced onto the Paleogene to Early Miocene sedimentary cover of the Bucovinian nappes..., conference