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The Carpathian-Pannonian Region (CPR) hosted some of the largest silicic volcanic eruptions in Europe during the Early and Middle Miocene, contemporaneously with major lithospheric thinning of the Pannonian Basin. This was recorded as an ignimbrite flare-up event from approximately 18.1–14.4 Ma. To gain in-depth perspectives on the eruption chronology, tephrostratigraphy, and petrogenesis at the onset of CPR silicic volcanism, we applied a multi-proxy approach to Lower Miocene rhyolitic ignimbrites and pyroclastic fall deposits from the northern CPR to the Dinaride Lake System. High-precision zircon U-Pb geochronology distinguished two Lower Miocene groups of volcaniclastic rocks at ∼ 18.1 Ma and ∼ 17.3 Ma. Based on combined tephrostratigraphic signatures we propose that the ∼ 18.1 Ma Kalnik and ∼ 17.3 Ma Eger eruptions produced widespread (intermediate to) large caldera-forming massive rhyolitic ignimbrites, deposited across northern and southwestern regions of the CPR. Due to easterly winds that carried volcanic ash hundreds of kilometers to the southwest, Eger eruption products also reached distal intra-montane Dinaride lacustrine basins, recorded as pyroclastic fall deposits. Heterogeneous major and trace elemental compositions of ∼ 18.1 Ma volcanic glass shards suggest that the Kalnik eruption was sourced from complex silicic magmatic systems, with simultaneous tapping of two discrete melt bodies during the eruption. The homogeneous geochemical composition of ∼ 17.3 Ma glasses is distinct from the older glasses. Integrated zircon and bulk glass Nd-Hf isotope compositions have a positive correlation, defining a regional mantle array, and are more radiogenic in the younger phase of volcanism. The recorded systematic isotopic change, moving from older more crustal signatures to younger more juvenile compositions, imply that during the period of lithospheric thinning of the Pannonian Basin the region underwent more complex variations in the interaction between metasomatized lithospheric mantle-derived magmas and various crustal components than previously recognized.

The Bükk Mts. in NE Hungary exposes Paleozoic and Mesozoic successions containing volcanic formations both in the oceanic crust-derived Szarvaskő Unit and in the continental crust-derived Paraautochthonous Unit. The rocks of this latter unit were subject of multiple metamorphic, also metasomatic alterations and deformation events obscuring and overprinting original petrographic and geochemical characteristics and producing a complex structure in which stratigraphic relationships are not always possible to be identified. This situation was leading to various stratigraphic hypotheses. This study aims to provide a basis for distinguishing metavolcanic formations using trace element geochemical data combined with quantitative mineralogical data based on XRD and EPMA. Our data were obtained from a wide range of samples collected in the Bükk Mts. Mineralogy and major element geochemistry reflect regional Alpine metamorphism and local alteration processes but high field strength elements remained relatively stable during most of these processes except local HFSE enrichment. Zr/TiO2, Nb/Y and Nb/Ta ratios were effectively used for classifying the rocks into three formations: Bagolyhegy Metarhyolite, Szentistvánhegy Metavolcanics and Szinva Metabasalt. Bagolyhegy Metarhyolite is a unique volcanic formation formed from highly differentiated and HFSE-depleted magma, probably in a single volcanic centre of uncertain age. Szentistvánhegy Metavolcanics comprises heterogeneous rocks of a calc-alkaline arc-type suite with wide distribution in a Ladinian chronostratigraphic horizon. Szinva Metabasalt represents within-plate-type alkaline lava flows and adjacent volcaniclastic, mostly peperitic rocks embedded in Carnian platform and basin facies limestone formations. Like the sedimentary formations of the Bükk Mts, rocks of magmatic origin can be correlated with the formations of the South Alpine and Dinaric successions with the significant difference that abundant metavolcanics are not accompanied by intrusive bodies.

The silicic flows and domes can impose mechanical and thermal stress on the underlying substrate causing mineralization and lithification of granular bodies. In addition, the released water from the permeable substrate as dominant volatile species can contribute to the glass hydration of the flow. This fluid-lava interaction can be directly studied in ancient successions with exposed contacts. The Lebuj flow (Tokaj Mountains, Hungary) developed in a Miocene caldera setting, where the erosion revealed its basal zone including lava-substrate interaction textures. The main textural units comprise (1) a rhyolitic lava flow (F1: perlitic glass with obsidian marekanite, F2: microcrystalline-glass transition and F3: a basal breccia layer) and (2) the underlying mixed substrate unit (S1: massive rhyolite and breccia S2: enclosed partially sintered rhyolite tuff). The thin section textural analyses were completed by BSE imaging, Raman mapping (SiO2 polymorphs) and FTIR spot measurement (perlite H2O, clays). Glass transition temperature (Tg) was estimated using the chemical based GRD model.The flow margin contacted with underlying volcanoclastic deposits along a steeply inclined (50-75°) plane with subordinate fragmentation. The substrate suffered re-heating by the flow where porosity loss and welding (solid-state sintering) occurred. The silica polymorphs are observed growing into open pore spaces and fractures and interpreted as precipitates from vapor phase fluids passing through the permeable lithologies. The smectite group minerals typically record acidic type alteration, where the water-rock interaction commonly produces glass replacement minerals. The FTIR-identified clays (mixed layer kaolinite/montmorillonite or beidellite) indicate low-to medium alteration degree (estimated temperature between 50-100 °C).The lithophysae, spherulites and microcrystalline bands in the flow unit are textural evidence for prolonged groundmass crystallization above Tg. The relict obsidian grains in the glass are proofs of an incomplete hydration process. The FTIR and BSE investigations demonstrate the presence of sharp transitions from the hydrated ~3 wt.% perlitic rims to non-hydrated obsidian cores.Textural and mineralogical evidence suggest that the following series of events occurred as the consequences of the lava-substrate interaction: a) a viscous rhyolite flow advanced on an irregular topography; b) shear and brittle fracturing occurred at the contact; c) groundmass crystallization (above Tg, ~ 690-715 °C) and hydration (below Tg) acted in the flow; d) low temperature mineralization and variable scale sintering occurred in the substrate (below Tg). According to the fluid exchange model beneath silicic lava domes (Ball et al. 2015), the water – rock interaction resulted in weak hydrothermal alteration of the substrate and water flux to the quenched glass (flow). As an interaction of the two processes, the increased sintering and mineralization reduced the porosity of the substrate which probably restricted further water uptake for hydration. Thus the obsidian results from a ‘quenched’ hydration front (Bindeman and Lowenstern 2016). Ball J.L., Stauffer P.H., Calder E.S., Valentine G.A. (2015). Bull Volcanol 77:1–16.Bindeman I.N., Lowenstern J.B. (2016). Contrib to Mineral Petrol 171:89 AknowledgementsThis research has been funded by the Hungarian–Italian MTA-CNR bilateral research project 2019–2022. The research was also supported by Development and Innovation Office–NKFIH No. 131869 OTKA project. RL was supported by the Bolyai János Research Fellowship.

Ciomadul volcano, located at the south-eastern terminus of the Carpathian volcanic arc (Romania), is the youngest volcano in eastern-central Europe, with the last eruption occurring at 32 ka. Petrological and geophysical constraints indicate a melt-bearing silicic crystal mush body beneath Ciomadul, approximately 5–20 km below surface. This suggests that long-dormant or seemingly inactive volcanoes may have potentially active magma storage systems. However, the geometry and size of the magma storage region is unknown. Understanding the nature and structure of the volcanic plumbing system is crucial to understanding the evolution of the system, as well as to assess the hazard potential.In this presentation, we will report on 41 new magnetotelluric measurements acquired in 2022. The survey design consists of an irregular grid with dimensions of approximately 75 km by 75 km, centered around Ciomadul in the corner of the south-eastern Carpathian Mountains. This makes an array suitable for three-dimensional modelling. A 100 km long NW-SE transect across the array has a measurement spacing of less than 15 km.The newly acquired data complement previous measurements (recorded in 2010) near Ciomadul and Băile Tuşnad within an area of approximately 5 km by 10 km. The new data extend westward to the Perşani volcanic field (Racoș, Homorod), about 40 km west of Ciomadul, towards the Transylvanian Basin, and to the south-east to the edge of the seismically active Vrancea zone, often attributed to the descent of a slab, more than 50 km south-east of Ciomadul, towards the Focșani Basin. Both regions are targets for future measurement campaigns.Recordings were carried out at each location for approximately 1–5 days. The data typically had reliable periods of up to 1,000–4,000 s. The data are not homogenous and have characteristics of three-dimensionality. At some locations, cultural electromagnetic noise contaminated the signals and degraded the data; thus choosing appropriate locations for measurement was critical. Estimating local and inter-station transfer functions required special care, such as applying data pre-selection schemes and manual time windows, in addition to standard approaches including using robust statistics and the remote reference method. Overall, the preliminary analysis is encouraging and the results show that it is possible to obtain usable magnetotelluric data in this region.

A geochronological study of the St Georgen tuff, favourably positioned within the Middle Miocene marine succession of the Vienna Basin, is essential to our understanding of the timing of the middle Badenian transgression. We report here new data on the separated zircon U–Pb ages/phase chemistry and the clay mineralogy of altered tuffs and then use these data to infer the provenance of the tephra and the palaeoenvironmental conditions. The ages of the tuff range between 15.78 ± 0.27 and 14.36 ± 0.31 Ma, with a weighted mean age of 14.59 ± 0.2 Ma. This defines the onset of the second Badenian transgression in the Central Paratethys region, which was the strongest transgression in the entire Miocene record of the Vienna Basin. The compositional and temporal relationships between the tuff and the neighbouring volcanism suggest that the Harsány eruption in the central Pannonian Basin is the most plausible source region for the tephra. West- and SW-directed tropospheric trade winds or easterlies were responsible for the transport of the Harsány tephra to its present location. The prevalence of halloysite, in addition to post-depositional alteration reactions (glass–smectite–halloysite and kaolinite–halloysite) suggest the fallout of tephra in a very shallow sea, which may have been affected by seasonal wetting and drying cycles at the onset of ash deposition. Supplementary material: Halloysite mineralogy, global geochemistry and U-Pb zircon age data are available at https://doi.org/10.6084/m9.figshare.c.6294944

Two-mica leucogranites and/or granodiorites, often affected by various degrees of post-emplacement deformation and/or metamorphism (i.e., sheared granites, metagranites or orthogneisses), occur in several parts of the Tisza Mega-unit (Carpathian–Pannonian region), including the Apuseni Mts. (Romania), the Papuk Mt. (Croatia), and basement highs of the Pannonian Basin (Battonya–Pusztaföldvár and Algyő–Ferencszállás areas, SE Hungary). Despite the similar petrological characteristics (e.g., mineralogical composition, texture), these formations have not been compared to each other yet for correlational purposes and the scarce geochemical and almost completely lacking geochronological records also demanded further petrological investigations and datings.Petrographically, granitoids from all the studied areas (SW Apuseni Mts., Papuk Mt. and the previously mentioned basement highs) proved to be similar, medium to coarse-grained monzogranites or granodiorites, containing quartz, plagioclase, K-feldspar, biotite, and muscovite. In some quarries or rarely in drill cores aplites and pegmatites were also found. As accessory components most commonly apatite, zircon, monazite, and xenotime, occasionally garnet were identified. As secondary phases sericite, albite, chlorite, epidote, kaolinite, and calcite appear frequently. Whole-rock geochemistry revealed that despite the various post-magmatic alterations (deformation/metamorphism/fluid effects etc.), the majority of the granitoids preserved their primary major and trace element compositions. All of them proved to be subalkaline, peraluminous, alkali-calcic or calc-alkalic with basically magnesian and S-type (rarely S/I-type) character. Major and trace element distributions, chondrite-normalized REE patterns (with slight negative Eu anomalies) and other relatively immobile trace element (HFSEs) concentrations showed significant similarities among the studied samples suggesting their common origin and local correlation possibilities within the Tisza Mega-unit. Interestingly, samples from the Papuk Mt. geochemically differ from the others as well as the aplites and pegmatites associated with the Codru granitoids (Apuseni Mts.). The former might represent a different source and igneous episode; however, the geochemical distinction of the latter (with more pronounced negative Eu anomaly and lower concentrations in REEs and HFSEs) is rather odd. Trace element-based discrimination diagrams (e.g., Yb vs. Ta, Yb+Ta vs. Rb) suggested that most of the studied rocks are volcanic-arc granites and only a few of them (basically aplites and pegmatites) are syn-collisional despite their typical S-type mineralogy (e.g., muscovite, monazite, garnet) that unequivocally referred to continental crustal sources.Considering another means of geotectonic discrimination (e.g., Sr/Y and La/Yb ratios) and the ascertainment of Broska et al. (2022) in case of Western Carpathians granitoids, it is feasible that the studied granites bear the geochemical signature of a slab break-off, being crust- and mantle-derived, too, while shallower level melts (aplites and pegmatites) represent purely crustal sources in the Variscan orogeny. The latter corresponds to the calculated zircon saturation temperatures, as well (granites: 740–780 °C, aplites/pegmatites: 580–600 °C).Preliminary datings (Battonya granitoids, SE Hungary) suggested that the main zircon crystallization period occurred in the Early Carboniferous (356 Ma) that fits well into the regional geological framework of the European Variscides.This study was financed by NRDIF (K131690).Broska, I., Janák, M., Svojtka, M., Yi, K., Konečný, P., Kubiš, M., Kurylo, S., Hrdlička, M., Maraszewska, M. (2022). Lithos 412–413:106589

The timing of Triassic magmatism of the Ditrău Alkaline Massif (Eastern Carpathians, Romania) is important for constraining the tectonic framework and emplacement context of this igneous suite during the closure of Paleotethys and coeval continental rifting, as well as formation of back-arc basins.Our latest geochronological data refine the previously reported ages ranging between 237.4 ± 9.1 and 81.3 ± 3.1 Ma. New K/Ar and U–Pb age data combined with all recently (post-1990) published ages indicate a relatively short magmatic span (between 238.6 ± 8.9 Ma and 225.3 ± 2.7 Ma; adding that the most relevant U–Pb ages scatter around ∼230 Ma) of the Ditrău Alkaline Massif. The age data complemented by corresponding palinspastic reconstructions shed light on the paleogeographic environment wherein the investigated igneous suite was formed.The magmatism of the Ditrău Alkaline Massif could be associated with an intra-plate, rift-related extensional tectonic setting at the southwestern margin of the East European Craton during the Middle–Late Triassic (Ladinian–Norian) period.

By investigating fossil eruption products, we can better understand the behaviour of volcanoes and the processes occurring well beneath the volcanic edifice, leading to eruptions. In a felsic, crystal-rich (> 50 volume%), long-dormant mushy system, one of the most critical rejuvenation factors is the addition of hot mafic magma. In the case of Ciomadul volcano (Southeast Carpathians), a dominantly explosive eruption phase occurred at 56-50 ka following a ca. 40 kyr long dormancy. Three eruption units were studied in detail: Băile Tuşnad (Ee5/1tf), the Covasna–Harghita frontier (Ee5/1kh) and Mohoş roadcut (Ee5/1mo). Pumices from these locations have relatively high-Mg values (avg. of 0.56-0.62 mol%) and similar Sr/Y (147-157, but 225 in the Ee5/1tf) and Dy/Yb (1.71-1.73, but 1.89 in Ee5/1tf) ratios akin to the adakite-like rocks. Variation of these bulk pumice as well as the titanite trace element ratios indicates early garnet fractionation or residual garnet in the mantle source region. Trace element signature of the pumices shows strong enrichment of Ba and Sr and a depletion in heavy REE suggesting that the primary magmas originated by partial melting of strongly metasomatized lithospheric mantle.Mineralogy of the pumices is plagioclase, amphibole and biotite phenocrysts and apatite, titanite, zircon and FeTi oxide accessories. Mafic crystal clots of orthopyroxene, clinopyroxene surrounded by amphibole occur occasionally. Among the phenocrysts, amphibole shows a complex compositional zoning. One of the most particular features is the appearance of high-Mg and low-Al cores, found very rarely, if any, within amphibole, worldwide. Trace element composition of amphiboles shows also considerable variation and suggest crystallization at various magmatic environments. The high-Mg and low-Al amphibole xenocrysts have also peculiar rare earth element patterns: they have relatively low total REE content and a strong depletion in heavy REE. This REE pattern is akin to the amphiboles found in metasomatized spinel harzburgites and xenoliths showing melt-solid reaction. We assume that these amphiboles could have been a near-liquidus phase consistent with an ultrahydrous equilibrium melt. Trace element composition of these early formed amphiboles is thought to reflect the composition of the amphiboles at the source region, i.e. shows an inherited nature. The strongly hydrous nature of the primary magmas is reflected also by the incongruent transition from pyroxenes to amphiboles as shown by the mafic clot textures.Petrological features of the pumices suggest that eruption took place by reactivation of a relatively cold (T=700-775 °C), dacitic crystal mush. Rejuvenation was triggered by recharge of hydrous, less viscous mafic magma carrying the early formed crystal assemblage. Reheating and volatile flux initiated rapid remelting, magma ascent and eruption as indicated by thin overgrowth in amphibole and plagioclase and the lack of reaction zone around amphibole. This eruption scenario might have an implication for rapid reactivation after long dormancy in case of apparently inactive volcanoes.This research was supported by the Hungarian National Research, Development and Innovation Fund (NKFIH) within K135179 project and the ÚNKP-21-3 New National Excellence Program of the Ministry for Innovation and Technology from the source of the NKFIH.

A kutatás célja: Vizsgálatunk célpontjában a Sapientia Erdélyi Magyar Tudományegyetem Marosvásárhelyi Kar hallgatóinak jólléte, pszicho-szociális jellemzői, mentális állapota és egészségmagatartása áll. Módszerek: Vizsgálatunk eszköze egy standardizált kérdőív, melyet a 2018-2019-es tanév őszi félévében alkalmaztunk. A kérdőív az következő standardizált kérdőíveket is magába foglalta: Önértékelési Kérdőív (RSESH), Életcél Kérdőív (Purpose in Life Test – PIL), Észlelt stressz-kérdőív (Perceived Stress Scale – PSS4), Lelki egészség (General Health Questionnaire, GHQ-12). A vizsgálatban 206 hallgató vett részt a Sapientia EMTE Marosvásárhelyi Karáról. Eredmények: Az alacsony önértékelésű hallgatók gyakrabban fogyasztanak alkoholt, mint az egészséges önértékeléssel rendelkező társaik. Azok a hallgatók fogyasztanak több alkoholt, akik több pszichés problémával rendelkeznek, mint a társaik. Az alacsonyabb önértékelésű hallgatók gyakrabban fogyasztanak alkoholt a lerészegedésig, mint a normális önértékelést mutató társaik. A testedzés védő faktornak bizonyult az egészségmagatartás tekintetében, így akik aktívan sportolnak, jobb mentális állapotnak és alacsonyabb stressz-szintnek örvendenek, mint a keveset sportoló társaik. A pszichés állapot társadalmi meghatározottságát adataink is alátámasztják.

Similarly to other countries in the Eastern European Region, the situation of medical assistants in Romania is fairly difficult. Due to the lack of personnel, health professionals are typically overwhelmed with work. The Quality of Life Research Centre at Sapientia Hungarian University of Transylvania conducted a non-representative survey among medical assistants in Romanian state-owned healthcare institutions. The sample size is 312 Romanian and Hungarian speaking nurses from six counties. The present study problematizes the mental health of medical assistants, more precisely burnout and depression, along demographic, social, and labour market features. The determinants of burnout and depression are being searched for among these structural and situational variables, and their controlled impact is being assessed with linear regression. Results indicate an excessive risk of burnout and depression for nurses with lower-qualification working in outpatient care. Differences in the mental health of medical assistants echo to a large extent social inequalities, so that controlled for covariates, household income has a significant impact upon burnout and depression. From demographic agents, the protective effect of partnership is outstanding, and the number of supportive relationships is a protective factor of its own right against both burnout and depression. Female assistants are more at risk for depression but not for burnout, whereas workload increases the risk of burnout but not of depression. The analysis takes sides of the distinctness of burnout and depression. Although both syndromes are largely influenced by social features, burnout seems to be more situationally influenced whereas depression more structurally affected.

Two distinct Permian volcanic epochs were revealed in the Pannonian Basin (eastern Central Europe) by U–Pb zircon geochronology: an older one (~ 281 Ma, Cisuralian) in the ALCAPA Mega-unit (Central Transdanubia, Hungary) and a younger volcanic episode (~ 267–260 Ma, Guadalupian) in the Tisza Mega-unit (Southern Transdanubia and the eastern Pannonian Basin, Hungary). The former is represented by dacitic subvolcanic rocks (dykes) and lavas, while the latter is dominantly by crystal-rich rhyolitic–rhyodacitic/dacitic ignimbrites and subordinate rhyodacitic/dacitic lavas. Whole-rock (major and trace element) geochemical data and zircon U–Pb ages suggest close relationship between the samples of Central Transdanubia and volcanic rocks of the Northern Veporic Unit (Western Carpathians, Slovakia), both being part of the ALCAPA Mega-unit. Such correlation was also revealed between the Permian felsic volcanic rocks of the Apuseni Mts (Romania) and the observed samples of Southern Transdanubia and the eastern Pannonian Basin that are parts of the Tisza Mega-unit. The older volcanic rocks (~ 281–265 Ma) could be linked to post-orogenic tectonic movements, however, the youngest samples (~ 260 Ma, eastern Pannonian Basin, Tisza Mega-unit) could be formed in the extensional setting succeeding the post-collisional environment. On the whole, the observed Permian magmatic rocks show significant similarity with those of the Western Carpathians.

Ciomadul is the youngest volcanic system in the Carpathian-Pannonian Region recording eruptive activity from ca. 1 Ma to 30 ka. Based on combined zircon U-Th and (U-Th)/He geochronology, Ciomadul volcanism is divided into two main eruptive periods: Old Ciomadul (1 Ma – 300 ka; OCEP) and Young Ciomadul Eruptive Period (160–30 ka; YCEP). OCEP activity comprises Eruptive Epochs 1–3, whereas new ages for eight lava domes and four pyroclastic units belonging to the YCEP lead to its further subdivision into two eruptive epochs: Eruptive Epochs 4 and 5. The extrusion of most of the lava domes occurred between 160 and 90 ka (Eruptive Epoch 4) during three eruptive episodes at ca. 155 ka, 135 ka and 95 ka (Eruptive Episodes 4/1, 4/2 and 4/3, respectively) along a NE-SW lineament, which is perpendicular to the regional NW-SE trend of the Calimani-Gurghiu-Harghita volcanic chain. Eruptive Epoch 5 occurred after a ca. 40 kyr of quiescence at ca. 55–30 ka, and is mainly characterized by explosive eruptions with a minor lava dome building activity. All of the dated pyroclastic outcrops, together with the lava dome of Piscul Pietros, belong to the older Eruptive Episode 5/1, with an eruption age of 55–45 ka. The eruption centers of Eruptive Epoch 5 are located at the junction of the conjugated NW-SE and NE-SW lineaments defined by the older eruptive centers. The whole-rock geochemistry of all studied samples is fairly homogeneous (SiO2 = 63–69 wt%, K2O = 3–4 wt%). It also overlaps with the composition of the lava domes of the Old Ciomadul Eruptive Period, implying a monotonous geochemical characteristic for the past 1 Myr. The eruption rates for the Ciomadul volcanism were determined based on the erupted lava dome volume calculations, supplemented with the eruption ages. The activity peaked during the Eruptive Epoch 4 (160–90 ka), having an eruption rate of 0.1 km3/kyr. In comparison, these values are 0.05 km3/kyr for the YCEP (160–30 ka) and 0.01 km3/kyr for the overall Ciomadul volcanism (1 Ma–30 ka). Based on the geochemical characteristics, the quiescence periods and the lifetime of the complex, as well as the relatively small amount of erupted material, this volcanic system can be placed in a subduction-related post-collisional geodynamic setting, which shows strong chemical similarities to continental arc volcanism. The commonly found long repose times between the active phases suggest that the nature of a volcano cannot be understood solely based on the elapsed time since the last eruption. Instead, comprehensive geochronology, coupled with the understanding of the magma storage behavior could be a base of hazard assessment for volcanic fields, where the last eruptions occurred several 10's of thousand years ago and therefore they are not considered as potentially active.

Since its recognition as an impact structure 60 years ago, no volcanics were anticipated in the circular depression of the 14.8 Ma old Nördlinger Ries. Here, we describe for the first time a volcanic ash‐derived clinoptilolite‐heulandite‐buddingtonite bed within the 330 m thick Miocene lacustrine crater fill. Zircon U‐Pb ages of 14.20 ± 0.08 Ma point to the source of the volcanic ash in the Pannonian Basin, 760 km east of the Ries. The diagenetically derived zeolite‐feldspar bed occurs in laminated claystones of the Ries soda‐lake stage and represents the first unequivocal stratigraphic marker bed in this basin, traceable from marginal surface outcrops to 218 m below surface in the crater center. These relationships demonstrate a deeply bowl‐shaped geometry of crater fill sediments, not explainable by sediment compaction and corresponding stratigraphic backstripping alone. Since most of the claystones formed at shallow water depths, the bowl‐shaped geometry must reflect 134 +23/−49 m of sagging of the crater floor. We attribute the sagging to compaction and closure of the dilatant macro‐porosity of the deeply fractured and brecciated crater floor during basin sedimentation and loading, a process that lasted for more than 0.6 Myr. As a result, the outcrop pattern of the lithostratigraphic crater‐fill units in its present erosional plane forms a concentric pattern. Recognition of this volcanic ash stratigraphic marker in the Ries crater provides insights into the temporal and stratigraphic relationships of crater formation and subsidence that have implications for impact‐hosted lakes on Earth and Mars., Plain Language Summary: We describe for the first time a volcanic ash layer from the lake sediment fill of the 14.8 million years old asteroid impact crater Nördlinger Ries. Radiometric age and trace element characteristics of this ash layer are identical to that of a volcanic field in Hungary, so that the ash reflects a volcanic eruption 760 km east of the Ries basin. Recognition of this ash layer enables its use as a marker bed. The ash layer can be traced from surface outcrops to 218 m depth in drillings. This indicates that the strata are significantly inclined toward the crater center. Calculations of sediment compaction by further sediment load and burial only partially explain the observed deeply bowl‐shaped geometry. We attribute the additional sagging to the subsidence of the crater floor substrate, formed of rocks highly shattered by the impact event. Both effects cause a concentric pattern of outcropping strata in the partially eroded crater fill. The presence of the ash layer and its use to help disentangle the source and timing of subsidence (due to compaction of lake sediments, and closure of deeper, impact‐induced fractures), has important implications for lakes formed in impact craters on Earth and Mars., Key Points: A critical question in the evolution of impact‐crater‐hosted lakes is the origin and timing of post‐impact floor subsidence We describe a volcanic ash layer from the Ries impact crater that demonstrates a deeply bowl‐shaped geometry of its lacustrine crater fill This geometry, leading to a concentric outcrop pattern, requires significant crater floor sagging, in addition to sediment compaction, German Research Foundation, Chinese Scholarship Council, Bolyai J. Research Fellowship

Ciomadul is the southernmost eruptive centre of the post-collisional Călimani-Gurghiu-Harghita andesitic-dacitic volcanic chain (SE Carpathians, Romania) and represents the latest manifestation of the Neogene to Quaternary volcanism in the Carpathian-Pannonian Region. Ciomadul consists of older, peripheral shoshonitic to dacitic lava domes formed episodically between 1 Ma and 300 ka and a voluminous, central volcanic complex developed within the last 200 ka. Although several lines of evidence (based on petrology, geophysics and gas monitoring) suggest a long-lived magmatic plumbing system holding a potentially active magma storage (“PAMS” volcano) beneath Ciomadul, the pre-eruptive conditions of the upper crustal magma reservoir (including temperature, oxygen fugacity and TiO2 activity) are not completely explored so far. In this study 23 rock samples, representing the whole volcanic activity of Ciomadul in time, were involved. Fe-Ti oxide (magnetite-ilmenite) grains were selected from magnetic heavy minerals, but only a few of the samples contained both magnetite and ilmenite crystals. Equilibrium between Ti-magnetite and ilmenite was tested by their chemical composition (Mg/Mn ratios).Various geothermobarometer calibrations, including Andersen and Lindsley (1985, 1988) as well as Ghiorso and Evans (2008), were applied to calculate temperature and oxygen fugacity from Fe-Ti oxide compositions. Our results show that, in case of dacitic pyroclastic rocks, temperature values gained by the method of Ghiorso and Evans are significantly lower (640–780 °C) than those obtained by the geothermometers of Andersen and Lindsley (1985, 1988), showing 750–830 and 710–790°C temperatures, respectively. On the other hand, andesitic lava dome rocks of Dealul Mare show higher, 800–900 °C temperature according to all of these methods. The obtained temperature was compared with amphibole-plagioclase thermometry results and this shows a better agreement with the values yielded by the Andersen and Lindsley (1985) Fe-Ti oxide thermometry, particularly for the pumice samples.In case of oxygen fugacity, the Ghiorso and Evans (2008) and Andersen and Lindsley (1985) methods showed fairly similar values (fO2=0.9–1.8) whereas the Andersen and Lindsley (1988) calculations gave higher oxygen fugacity (fO2=1.1–2.5). Nevertheless, these results, irrespective the applied calculation methods, suggest relatively oxidized conditions (ΔNNO>1) what is comparable with many other andesitic to dacitic volcanic systems (e.g. Mount St. Helens, Mount Unzen, Santorini). Values of TiO2 activity was calculated and obtained a range between 0.76 and 0.98 what is consistent with the common presence of titanite. This study was financed by NKFIH K135179 project. Andersen, D.J. & Lindsley, D.H. (1985). EOS Transactions of the American Geophysical Union, 66, 416.Andersen, D.J. & Lindsley, D.H. (1988). Amer Miner 73:714–726.Ghiorso, M.S. & Evans, B.W. (2008). Amer J Sci 308:957–1039.

Haramul Mic is a ~0.15 km3 volume, crystal-rich, homogeneous, high-K dacite lava dome, which is one of the oldest ones in the Ciomadul Volcanic Complex (Romania, eastern-central Europe). The eruption that formed the lava dome occurred after about 200.000 years of quiescence. Eruption age of the dome determined by (U-Th)/He dating on zircon gave 154 +/- 16 ka that is in agreement with the youngest zircon U-Th outer rim date (142 +18/-16 ka). The apparently continuous crystallization of zircon between the eruption age and the 306 +/- 37 ka oldest zircon core date records a long-living magmatic plumbing system.The Haramul Mic lava dome rock has 35-40% average crystal content and consists of plagioclase, amphibole, biotite and accessory zircon, apatite, titanite and Fe-Ti oxides. The groundmass is mainly built up by perlitic glass with some microlites and sheared vesicles. The dacite contains sparse mafic enclaves with K-rich, shoshonitic bulk composition, composed of plagioclase and biotite in addition to less amount of amphibole. Felsic crystal clots are more common and they comprise plagioclase, amphibole, biotite and interstitial vesicular glass.Trace element content of the mineral phases and the groundmass glass was determined by LA-ICP-MS. All of the studied phases show homogeneous trace element compositions and along with the textural characteristics these imply general equilibrium state in the magma storage system before the eruption. Amphibole-plagioclase geothermometer and geobarometer calculations result in 700-800 oC crystallization temperature and 200-300 MPa crystallization pressure.In order to reveal the magma chamber processes that triggered the eruption and formed the Haramul Mic lava dome after long quiescence time, it is necessary to understand better the behaviour of trace elements as the most sensitive indicators of magma reservoir mechanisms. We determined mineral-liquid trace element partition coefficients and evaluated the result in the context of crystal lattice strain model. They show many similarities with those proposed for the Fish Canyon Tuff dacite except for Li and Sc. The anomalous behaviour of Sc is clearly expressed by the elevated concentration in the glass phase and many times, there are some zonation in Sc from crystal core to rim. This could be explained either by inherently higher Sc content of the melt reflecting the nature of the primary magmas or by partial remelting of biotite just before the eruption. Significant positive anomaly of Li content can be observed in biotite crystals of the mafic enclave compared with the dacitic host rock. Li content of plagioclase varies between 15-30 ppm with slight rimward depletion.Eruption initiation cannot be explained by physical mixing of mafic recharge magma, but rather by volatile transfer or second boiling. The water-rich nature of the melt is reflected by the abundant vesicles in the glassy groundmass. Furthermore, the amphibole phenocrysts have sharp margin without resorption rim, which suggest hydrous melt phase and relatively fast magma ascent.This research belongs to the NKFIH-OTKA K135179 project and was supported by the ÚNKP-19-1 New National Excellence Program of the Ministry for Innovation and Technology.

We used combined trace element and U-Pb isotopic data of zircon from dacitic to rhyolitic pyroclastic rocks and Si-rich ash-bearing deposits to assess their tephrostratigraphic potential. Data were collected using LA-ICP-MS analyses, a rapid and cost-effective method, to obtain simultaneously trace element contents and U-Pb ages of a large number of zircon grains. The rationale in using zircon crystals for characterizing tephra deposits is that zircon is a resistant mineral phase and is usually a late crystallizing mineral in highly evolved magmas. Therefore, they are assumed to be in equilibrium with the erupted melt phase represented by the volcanic glass. Knowing the zircon/melt partition coefficients, equilibrium melt composition can be calculated even in cases when the volcanic glass in the pyroclastic material has undergone severe post-depositional alteration.We studied Miocene silicic pyroclastic deposits in a broad area including the Pannonian Basin (eastern-central Europe) and its surroundings to characterize and correlate the explosive volcanic products. In regional scale, these deposits are usually assigned as important stratigraphic key horizons within sedimentary successions and thus, they help to understand better the chronostratigraphic framework and palaeoenvironmental changes having affected the highly-dynamic Mediterranean-Paratethys system.The early to middle Miocene silicic pyroclastic deposits within the Pannonian basin are estimated to be more than 4000 km3 in volume within 4 Myr, suggesting an important ignimbrite flare-up event. At least 4 main eruption units were distinguished and characterized, each could have regional (>>100 km) effects. We demonstrate here the power of multivariate discriminant analyses as well as machine learning techniques in distinguishing the main eruptive units and their correlation with unclassified distal deposits based on zircon trace element data. The machine learning algorithms were trained using our zircon database with trace elements as input parameters. Both the discriminant analysis and the machine learning methods gave reliable results, i.e. distinguished the main 4 pyroclastic units and found the link of the distal deposits to them. As a result, we provide a robust zircon-based fingerprint that can be used as a proxy in tephrostratigraphy.Zircon trace element compositions indicate distinct silicic magmas resided partly coeval in the upper crust. Using trace element content of zircon and glasses from the same samples of crystal-poor ignimbrites, we determined zircon/melt partition coefficients. The obtained values of the 4 main units are very similar and comparable with published data for silicic volcanic systems. This suggests that zircon/melt partition coefficients in calc-alkaline silicic systems are not significantly influenced by melt composition at >70 wt% SiO2. These findings let us use these zircon/melt partition coefficients to calculate the equilibrium melt compositions for the pyroclastic occurrences even in case when no glass data were available. The zircon proxy approach can be limited by the non-existence of zircon in the rocks and also by the fact that no systematic compositional difference is found between eruption products, although the latter problem similarly stands for glass chemistry-based tephrostratigraphic studies.This study was supported by the NKFIH FK-131869 project.

Ciomadul is the youngest volcano in eastern-central Europe. Although its last eruption occurred at ca. 30 ka, there are independent indications for a high-crystallinity magma reservoir persisting beneath the volcano until present. In order to further test the hypothesis of long-lived melt presence and to better constrain the nature and timescales associated with the subvolcanic magma storage system, over 500 zircon U-Th and U-Pb spot ages (crystal interiors and outer surfaces) were interpreted from dacitic rocks of the most productive eruptive period (the Young Ciomadul Eruptive Period; YCEP, 160-30 ka). Zircon surface ages from lava dome and pumice samples range from ca. 600 ka up to the youngest eruption event at 30 ka. They form a continuous age distribution and some single crystals reveal significant age zonation (>150 kyr difference from core to rim). The oldest zircon ages of YCEP overlap with the last eruption events of the Old Ciomadul Eruptive Period (1000–330 ka). The zircon age spectra, combined with textural data, point to a prolonged (several 100's kyr) residence in a highly crystalline mush state. The range in zircon crystallization temperature (from ∼750 °C to the solidus at ∼680 °C) is consistent with the results of thermometry on amphibole and plagioclase from felsic crystal clots, which represent crystal mush fragments. To maintain magma reservoir for such a long time above solidus, continuous magma input by deeper recharge is required. Zircon crystallization model calculations constrained by thermal modelling imply an average rate of magma input of about 1.3 × 10−4 km3/yr over 2 Myr. Such estimate allows us to calculate an extrusive/intrusive ratio of 1:25–1:30. The model calculations suggest that a crystal mush zone of about 35 km3 is still present within the subvolcanic magma reservoir. Importantly, the Ciomadul plumbing system thus remains thermally primed and renewed magma injection could lead to rapid reawakening and eruption of the apparently inactive volcano.

Cultural landscapes were developed as a result of continuous interaction between nature and human culture. During their evolution, the geodiversity was also considerably influenced by human activities. Recently, geoheritage studies have become more sensitive towards man-made cultural landmarks. In this paper, we explore a methodology to compile a regional inventory for a historic mountainous cultural landscape with remarkable geological, volcanological, and mining heritage in Tokaj Mts, (NE Hungary). The databases of the natural and cultural heritage contribute to the extension of regional inventories with a large number of geodiversity-related records. The specific selection procedure with a combination of GIS and fieldwork assessment resulted in the final list of potential sites. The applied three stage classification forms a basis for territorial analysis. The selected 60 geosites of 700 km2 represents well the geological history of the study area, while another 160 geodiversity and geocultural sites emphasize further enhancement of natural and cultural diversity. The functional classification referring to the physical nature of the sites was useful to define specific conservation management priorities. The thematic grouping of the sites defined new interpretation possibilities for geotourism and geoeducation taking into account volcanological, geomorphological, and mining heritage values.

In the Carpathian–Pannonian region (Pannonian Basin, Hungary and the Apuseni Mts, Romania) several Late Paleozoic magmatic episodes were revealed by zircon U-Pb geochronology. These events were genetically controlled by a post-collisional to extensional tectonic regime and occurred along the European Variscan Orogenic Belt. Detailed geochronological and geochemical information about the products of this magmatism play crucial role in the regional correlation studies which is the main goal of our research.In the Tisza Mega-unit, including southern Transdanubia and the eastern Pannonian Basin (Hungary) as well as the Apuseni Mts (Romania), Permian felsic (dominantly rhyodacitic-dacitic) ignimbrites are common. In the western–central part of the Apuseni Mts, they are accompanied by basaltic and subordinate andesitic lavas, corresponding to a bimodal volcanic suite. Cogenetic plutonic (granites, diorites, gabbros) and subvolcanic rocks (felsic–intermediate dykes) occur in the SW part of the Apuseni Mts, Highiş massif. Immobile element features (REE patterns and multi-element spider diagrams) are similar for all of the aforementioned rock types, suggesting fractional crystallization from a common or similar source. Zircon U-Pb ages of this cogenetic rock assemblage overlap each other and fall within a ~10 Myr long time-span (269–259 Ma, Guadalupian). In contrast to the previous assumptions, the Permian felsic volcanites in the Tisza Mega-unit are not in connection with the granitoid rocks known in the basement of the eastern Pannonian Basin (e.g., Battonya granite). Based on our new data, the granitoids represent a Variscan (~356 Ma, Mississippian) plutonic body.The dacitic subvolcanic rocks (dykes) and lavas in the ALCAPA Mega-unit, Central Transdanubia (Hungary) represent an older (~281 Ma, Cisuralian) and geochemically distinct volcanic episode than the magmatism in the Tisza Mega-unit. Associated plutonic rocks, however, are not known in the study area.Regarding a broader correlation, the zircon U-Pb ages of the studied Permian plutonic and volcanic rocks of the Tisza Mega-unit are significantly younger than the ages of other well-studied parts of the Central European Variscides (e.g., Intra-Sudetic Basin, NE Germany) where much older ages were identified (300–280 Ma). On the other hand, felsic volcanic rocks of the ALCAPA Mega-unit do not differ from the aforementioned parts of the European Variscides in age. Based on whole-rock geochemistry and zircon geochronology, all of the observed Permian magmatic rocks show similarity with the Permian felsic volcanites of the Western Carpathians (Slovakia). Some further assumptions have been raised: (1) felsic volcanic rocks of the Tisza Mega-unit could correlate with similar rocks of the Southern Gemeric (Vozárová et al. 2009) and Silicic Units (Ondrejka et al. 2018) of the ALCAPA Mega-unit, while (2) the studied samples of Central Transdanubia might be in relationship with the felsic volcanites of the Northern Veporic Unit, ALCAPA Mega-unit (Vozárová et al. 2016). This study was financed by NRDIF (K131690).Ondrejka, M., Li, X.H., Vojtko, R., Putiš, M., Uher, P., Sobocký, T. (2018). Geol Carpath 69(2):187–198.Vozárová, A., Šmelko, M., Paderin, I. (2009). Geol Carpath 60(6):439–448.Vozárová, A., Rodionov, N., Vozár, J., Lepekhina, E., Šarinová, K. (2016). Geol Carpath 61:221–237.

Long-dormant volcanoes (quiescence time is several 100’s to 10’s thousand years between eruptions) pose a particular hazard, since the long repose time decreases the awareness and there is mostly a lack of monitoring. The Haramul Mic, a pancake-shaped flat dacitic lava dome is part of the Ciomadul Volcanic Complex in eastern-central Europe (Romania) and serves as an excellent example of such volcanoes. The Haramul Mic lava dome is the earliest product of the Young Ciomadul Eruption Period (YCEP), when the activity recrudesced in the area after about 200.000 years quiescence time. Eruption age of the dome determined by (U-Th)/He dating on zircon gave 154 +/- 16 ka that is in agreement with the youngest zircon U-Th outer rim date (142 +18/-16 ka). In the YCEP zircon crystallization dates record typically long, up to 350-400 kyr lifetime of the magmatic plumbing system, in case of Haramul Mic the oldest zircon core is 306 +/- 37 ka old.The 880.7 m high lava dome covers an area of 1.1 km2 and has a volume of ~0.15 km3. It is composed of crystal-rich homogeneous high-K dacite. The average crystal content is 35-40% and consists of plagioclase, amphibole, biotite and accessory zircon, apatite, titanite and Fe-Ti oxides. The groundmass is mainly built up by perlitic glass with some microlites. The dacite includes mafic enclaves having plagioclase and amphibole besides a large amount of biotite crystals, that eventuates K-rich, shoshonitic bulk composition. The dacite contains abundant felsic crystal clots which comprise plagioclase, amphibole, biotite and interstitial vesicular glass.Amphiboles are relatively homogeneous in chemical composition. They are low-Al hornblendes suggesting 700-800 oC crystallization condition at 200-300 MPa compared with experimental data. Al-in-hornblende geobarometer and amphibole-plagioclase geothermometer calculations give results reproducing these temperature and pressure ranges. Although the Kis-Haram dacite is fairly rich in 25-45 anorthite mol% plagioclase, no negative Eu anomaly can be observed in the bulk rock and the glass. Similarities between Fish Canyon Tuff and Kis-Haram rocks can be strikingly noted regarding the major and trace element contents of mineral phases, glass and bulk rock that all refer to a wet oxidised calc-alkaline magmatic system. The relatively small volume Kis-Haram lava dome represents a rejuvenated low-temperature granodioritic crystal mush having similar features as the large volume silicic eruption of Fish Canyon Tuff. Their recorded almost similarly long zircon crystallization intervals give an interesting aspect with regard to the thermal evolution of the magmatic system and eruption volumes.This research was financed by the Hungarian National Research, Development and Innovation Fund (NKFIH) within No. K116528 project and was supported by the ÚNKP-19-1 New National Excellence Program of the Ministry for Innovation and Technology.

The Ciomadul in eastern-central Europe is a high-K dacitic volcanic complex characterized by long quiescence (several 10’s of kyr) periods between eruptions and a long-standing (over several 100’s of kyr) magmatic plumbing system. Following intermittent lava dome extrusions from 1 Ma to 360 ka, a more intense eruption stage occurred between 160 ka and 30 ka with initial lava dome building period followed by dominantly explosive eruptions. The volcano has been again in a long quiescence stage since 30 ka, although results of geophysical studies suggest presence of a subvolcanic magma body with significant melt fraction. In order to constrain better the rejuvenation mechanism of such long-dormant volcanic complex, a more thorough understanding of the nature and dynamics of the magmatic plumbing system and the reason of eruption triggers is required. In spite of the homogeneous dacitic bulk rock composition and similar mineral assemblage, each eruption product shows subtle differences in mineral-scale features. Here, we present examples showing how basaltic magma played a role in the genesis of dacite as well as triggered eruption in a timescale of days to weeks.The Ciomadul dacites are crystal rich and contain plagioclase, amphibole and biotite as main phenocrysts in addition to accessory phases of apatite, titanite and zircon. Several dacitic lava dome rocks formed between 90 and 160 ka in Ciomadul contain also high-Mg minerals such as olivine, clinopyroxene and orthopyroxene. Cr-spinel inclusions occur in olivine, orthopyroxene and also in high-Al amphiboles. Textures and the high Mg-numbers (0.85-0.91) of these mineral phases suggest that they can be considered as antecrysts with magmatic origin having crystallised from primitive mafic magmas, which were involved in the evolution of the subvolcanic magma storage system. Zoning pattern and trace element content of plagioclases and amphiboles clearly show interaction between dacitic and basaltic magmas. In addition, these high-Mg minerals allow us to have an insight into the origin of the primary magmas as well as the dynamics of the mafic magma body stalled at the crust-mantle boundary.The compositions of the Cr-spinel inclusions significantly differ from those of the spinels in the 600-1200 ka alkaline basalts of the nearby Perşani Volcanic Field and their high Cr-numbers indicate a depleted mantle source for the parental magma. Such Cr-rich spinels are common in high-K magmas originated in metasomatized lithospheric mantle with depleted, harzburgitic lithology. Compositional zoning of clinopyroxenes indicates several recharge events by high-Mg and high-Cr basaltic magmas. Mafic magma batches repeatedly ascended and emplaced below the upper crustal felsic crystal mush and formed a dynamic interface between these two magmas. The mafic components remained in plastic state allowing thorough mixing of the mafic and felsic mineral cargos during turbulent convective magma stirring, whereas farther from this interface, remelting of the crystal mush occurred due to reheating and volatile transfer into the interstitial melt. The series of mafic magma injections increased the eruptible magma volume and occasionally led to eruptions.This research was financed by the Hungarian National Research, Development and Innovation Fund (NKFIH) within K116528 project.

BACKGROUND Bare-metal stents (BMS) are frequently implanted in elderly patients instead of drug-eluting stents (DES). We aimed to compare the prognosis of patients treated for myocardial infarction with the two types of stents over the age of 75. METHODS Data of patients registered in the Hungarian Myocardial Infarction Registry, a mandatory nationwide programme for hospitals treating patients with myocardial infarction were processed. From patients included between January 2014 and December 2017 we created two groups according to DES and BMS implantation. The outcome measures included all-cause mortality, the composite of cardiac events (MACE), repeated revascularisation and transfusion. Propensity score matching was used to balance the groups and Cox proportional hazards' models to estimate the risk during the 1st year after the index event. RESULTS From 7383 patients (age: 81.08 ± 4.38 years) 3266 (44.2%) patients received DES. The PS-matched cohort included 5780 cases with balanced characteristics. In the DES group, the mortality (HR 0.66 [0.60-0.72]), MACE (HR 0.66 [0.60-0.72]) and the rate of transfusion (HR 0.84 [0.73-0.97]) were significantly lower. The PS-matched cohort showed a similar trend but with a lower rate of benefits with a 21% reduction of mortality and 23% of MACE. Difference in transfusion did not reach the level of significance. In multivariate models, stent type prevailed as an independent predictor of mortality and but not of transfusion. CONCLUSIONS Based on our analysis of a real-life, high-risk population, implantation of DES seems to be an advantageous strategy for elderly patients.

The concept of geodiversity involving abiotic elements of the environment arose as a scientific topic in the last decade of the 20th century. The increasing number of geological exhibition sites and the public interest in the two domestic UNESCO Global Geoparks in Hungary (Novohrad–Nograd, Bakony–Balaton) indicated that geodiversity-based geotourism had become a development tool for disadvantaged peripheral regions. Such developments require multi-faceted professional inventory and assessment of the elements of geodiversity. Similar requirements are also necessary with respect to geoconservation and the evaluation of vulnerability risks. The basic unit of the geodiversity register is the geosite. This may include outcrops or man-made excavations, (abandoned) mines or other anthropogenic objects; the main point is that their identification is connected to the developing geological and geomorphological processes (e.g. geosites with volcanic or karstic features). Based on the above, this study provides an overview of the development in geosite assessment and evaluation work, with special emphasis on the recently published details concerning two quantitative methods. This methodological basis was used to assess the well-known — albeit less representative — geosites of the domestic geological heritage. The scientific-educational, scenic–aesthetic potential and protection–degradation risk scores were determined discretely for 60 geosites. A particular focus was centred on the different nature conservation conditions (national park, landscape protection area, protected natural area, ex lege etc.), as well as on the development of the geo-touristic infrastructure (visitor centres, exhibition sites, nature trails). All this took place within the framework of the evaluation of additional interpretative and geo-touristic potential scores. The authors were actively involved in the establishment of a special Hungarian Geosite Day, with the specific aim of promoting the public dissemination of the geosciences.

Formation and evolution of the Pannonian Basin as part of the Mediterranean region was accompanied by eruptions of compositionally diverse magmas during the Neogene to Quaternary. The long-lasting magmatic activity began with some of the most voluminous silicic eruptions in Europe for the last 20 Myr. This paper describes the eruption chronology of this volcanic activity using new, high-quality zircon U-Pb dates, and provides the first estimates on the volume and areal distribution of the volcanic products, characterizes the magma composition and discusses the silicic magmatism in a region, where the continental lithosphere underwent significant extension. A thorough zircon geochronological study was conducted on samples collected from ignimbrites and pyroclastic fall deposits exposed in the Bukkalja Volcanic Field. In-situ LA-ICP-MS analysis on zircon grains provided a fast, cheap and accurate method for such detailed geochronological work, where the volcanic products occur in scattered outcrops that often have poor stratigraphic constraints. The interpreted eruption ages were determined from the youngest zircon age population within the samples and this methodology was validated by new single zircon CA-ID-TIMS dates and sanidine Ar-Ar ages. The volcanism covers about 4 Myrs, from 18.2 Ma to 14.4 Ma and involved at least eight eruptive phases. Within this, four large eruption events were recognized at 14.358 ± 0.015 Ma (Harsany ignimbrite), 14.880 ± 0.014 Ma (Demjen ignimbrite), 16.816 ± 0.059 Ma (Bogacs unit) and 17.055 ± 0.024 Ma (Mango ignimbrite), which are found in areas across the Pannonian Basin and elsewhere in central Europe. Considering all the potential sources of silicic ash found in the Paratethys sub-basins around the Pannonian Basin and along the northern Alps and in central Italy, we suggest that they were probably derived almost exclusively from the Pannonian Basin as shown by zircon U-Pb dates presented in this paper and published comparable age data from several localities. The new eruption ages considerably refine the Early to Mid-Miocene chronostratigraphy of the Pannonian basin, where the extensive volcanoclastic horizons are used as important marker layers. The cumulative volume of the volcanic material formed during this 4 Myr long silicic volcanism is estimated to be >4000 km3, consistent with a significant ignimbrite flare-up event. Zircon crystallization ages indicate magma intrusions and formations of magma reservoirs in the continental crust for prolonged period, likely >1 Myr prior to the onset of the silicic volcanism accompanied with sporadic andesitic to dacitic volcanic activities. Mafic magmas were formed by melting of the thinned lithospheric mantle metasomatized previously by subduction-related fluids and emplaced at the crust-mantle boundary. They evolved further by assimilation and fractional crystallization to generate silicic magmas, which ascended into the pre-warmed upper crust and formed extended magma storage regions. Zircon Hf isotope and bulk rock Sr-Nd isotopic data indicate a sharp decrease of crustal and/or increase of asthenospheric mantle input after 16.2 Ma, suggesting that by this time the crust, and the lithospheric mantle was considerably thinned. This magmatism appears to have had a structural relationship to tectonic movements characterized by strike-slip and normal faults within the Mid-Hungarian Shear Zone as well as vertical axis block rotations, when the two microplates were juxtaposed. Our new zircon ages helped to refine the age of two major block-rotation phases associated with faulting. This volcanism shows many similarities with other rift-related silicic volcanic activities such as the Taupo Volcanic Zone (New Zealand) and the Basin and Range Province (USA).

Noble gas isotopic composition of fluid inclusions was analyzed in amphibole, plagioclase and clinopyroxene phenocrysts from the shoshonitic and dacitic volcanic products of the Ciomadul volcanic dome field, the youngest volcanic system within the Carpathian-Pannonian Region. The highest Rc/RA ratios (3.0–3.8 RA) were obtained for high-mg clinopyroxene of the Malnas shoshonite. High-Al amphiboles from the Bixad dacitic pumices have Rc/RA ratios between 1.16 and 2.11 RA. These values overlap with the noble gas signature of the present-day CO2 emission. Thus, our new results reinforce the conclusion that the mantle component of the Ciomadul primitive magmas has relatively lower Rc/RA signature compared to the nearby Persani lithospheric mantle. This is likely due to the thorough metasomatic nature resulting in elevated large ion lithophile elements and high water content of the Ciomadul magmas. On the other hand, the Rc/RA ratios from plagioclase-hosted fluid inclusions and those from low-Al amphiboles are 0.06–0.12 RA and 0.39–0.77 RA, respectively defining a dominant crustal origin (>90%) for the trapped fluids. Noteworthy, these minerals represent a low-temperature crystal mush assemblage that existed for protracted time in the magma reservoir. We tested the fraction of mantle contribution for different mantle end-member values, considering also the effect of magma aging on the R/RA ratios due to longer (up to 50 kyr) residence time. This resulted in a maximum of ~50–60% mantle fluid contribution for the high-Al amphibole-hosted fluid inclusions and a lower, ~25% mantle fluid contribution, for the low-Al amphiboles. The elevated mantle fluid contribution in the case of the high-Al amphiboles can be explained by a fresh magma recharge event and shorter residence time before the eruption. The results of this study imply that fluid inclusion in primitive clinopyroxene and amphibole phenocrysts could reflect the magmatic end-member, which is in the case of Ciomadul a strongly metasomatized lithospheric mantle with relatively low Rc/RA values. Thus, the noble gas signature of the lithospheric mantle could be heterogeneous even in a restricted area.

Permian felsic volcanic rocks were encountered in petroleum exploration boreholes in SE Hungary (eastern Pannonian Basin, Tisza Mega-unit, Békés–Codru Unit) during the second half of the 20th century. They were considered to be predominantly lavas (the so-called “Battonya quartz-porphyry”) and were genetically connected to the underlying “Battonya granite.” New petrographic observations, however, showed that the presumed lavas are crystal-poor (8–20 vol%) rhyolitic ignimbrites near Battonya and resedimented pyroclastic or volcanogenic sedimentary rocks in the Tótkomlós and the Biharugra areas, respectively. The studied ignimbrites are usually massive, matrix-supported, fiamme-bearing lapilli tuffs with eutaxitic texture as a result of welding processes. Some samples lack vitroclastic matrix and show low crystal breakage, but consist of oriented, devitrified fiammes as well. Textural features suggest that the latter are high-grade rheomorphic ignimbrites.Felsic volcanic rocks in SE Hungary belong to the Permian volcanic system of the Tisza Mega-unit; however, they show remarkable petrographic differences as compared to the other Permian felsic volcanic rocks of the mega-unit. In contrast to the crystal-poor rhyolitic ignimbrites of SE Hungary with rare biotite, the predominantly rhyodacitic–dacitic pyroclastic rocks of the Tisza Mega-unit are crystal-rich (40–45 vol%) and often contain biotite, pyroxene, and garnet. Additionally, some geochemical and geochronological differences between them were also observed by previous studies. Therefore, the Permian felsic volcanic rocks in SE Hungary might represent the most evolved, crystal-poor rhyolitic melt of a large-volume felsic (rhyodacitic–dacitic) volcanic system.The Permian volcanic rocks of the studied area do not show any evident correlations with either the Permian felsic ignimbrites in the Finiş Nappe (Apuseni Mts, Romania), as was supposed so far, or the similar rocks in any nappe of the Codru Nappe System. Moreover, no relevant plutonic–volcanic connection was found between the studied samples and the underlying “Battonya granite.”

The South Alpine–Dinaridic realm was affected by igneous activity in the Middle Triassic; the marine carbonate platforms and the adjacent basins contain highly variable intrusive-volcanic assemblages. We studied the petrography and determined the zircon U–Pb ages of the Triassic volcanic products in the Transdanubian Range. The geochemical features and thus the geodynamic context of the magmatism are badly known, as the rocks experienced variable chemical alteration. The exact duration of the igneous activity is also poorly constrained, as the geochronological data of the former studies were obtained mostly by the weathering-sensitive K–Ar and Rb–Sr methods and thus some data even being younger than the age of the stratigraphic cover. The presence of andesite dikes and of pebbles and cobbles (

During the Mid-Miocene the northern part of the Pannonian basin was characterized by shallow- to deep-marine environments surrounding subaerial volcanoes. In the early stage of their activity (from about 18 Ma to 15-16 Ma), explosive eruptions of silicic magmas emplaced thick ignimbrite units party on land and partly underwater. After this first stage, magmatic activity became andesitic, giving raise to composite volcanoes as isolated islands (e.g., Visegrád Mts., Börzsöny, Cserhát and Mátra), like in the present Aeolian or Caribbean islands. The Mátra volcanic complex is one of the largest among them, built up following the major 14.9 Ma Demjén ignimbrite volcanic episode (Lukács et al. 2018). Although the building rocks of the volcanic edifice were studied in detail, less attention was given to the sedimentary sequences supplied at the periphery of the volcano, at the transition from subaerial to subaqueous environment. This work shows the preliminary results of a stratigraphic, sedimentological and petrographic study carried out on the sedimentary formation, cropping out between the villages of Tar and Sámsonháza (NW part of the Mátra Volcanic Field - Northern Hungary). Ten logs have been measured and correlated together for a 3D reconstruction of the sedimentary system, which progrades northwestward onto a plurimetric-thick ignimbrite deposit (Demjén ignimbrite). Channel and lobe deposits are packaged together in a thinning-upward sequence. In the channels, massive deposits are alternated to bedforms, indicating that both instantaneous hyperpycnal flows and slower flow dynamics were involved in the channel filling process. Gravel-size clast counts in the field and sandy-size point-counts in thin sections have been used to identify the different contributions of the eruption events, their rapid reworking and the erosion of older volcanic units to the sedimentary system. The absence of rounded clasts might indicate that the volcaniclastic sediments suffered minimal transport before being supplied to the sedimentary systems. The absence of any other, non-volcanic lithotypes might indicate that the volcanic center was isolated and the only sediment supplier of the basin. The gained results have a primary impact on the understanding of the complex dynamics that control the progradation of sedimentary sequences in shallow marine environment, proximal to composite volcanic centers.

This work focuses on the Miocene Telkibanya Lava Dome Field (Tokaj Mountains, Hungary), proposed as an example of poorly investigated lithofacies architecture of old silicic lava dome fields. A detailed fieldwork, combined with petrographic and radiometric (K/Ar dating) analyses, allows us the redefinition of the volcano-stratigraphy of a 25 km2 area, and the recognition of two temporary different generation of domes that grew in a subaerial environment. 12 cohesive and autoclastic lithofacies are identified and grouped together to document the internal variability of the domes, as well as the erosional phases that affected the lithofacies architecture. Furthermore, stratigraphy, lithofacies association and morphology allow recognizing the areal distribution of 5 lithosomes (lava flows, coulees or domes). All these findings represent a major breakthrough in the identification and interpretation of the volcanic processes that control the growth of silicic lava domes and their products in Late Miocene environment of Carpathian Pannonian region.

co-auteur étranger; International audience; Most active volcanoes display eruption frequencies of 10-1000s years but a class of volcanic systems has extremely long repose-time (>10's kyr), and are deemed as extinct. Yet, some reawaken, posing a particular threat because little is known about the way they endure and stir back to life. Reawakening primarily depends on the nature of the subvolcanic magma reservoir, especially the presence and distribution of melt. Here, we integrate petrology, thermobarometry, thermomechanical models, geophysics and in situ electrical conductivity measurements to show that the magma storage beneath Ciomadul, a seemingly inactive volcano in eastern-central Europe that last erupted 30 ka, may still hold 20 to 58 km3 of water-rich silicic melt, constituting up to 20-58% in parts of the upper crustal crystal mush body. Such a melt volume exceeds the volume of erupted lava over the entire history of the volcano. This illustrates the important longevity of a magmatic reservoir at temperature above the solidus, which implies that there is still a potential for rapid mush rejuvenation. That a seemingly dead volcano like Ciomadul is actually capable of erupting in the future calls for renewed attention to “inactive” volcanoes worldwide and perhaps for a redefinition of their activity/inactivity status.