In the Dinaridic Ophiolite Belt, small (m-scale) to large (km-scale) blocks of Middle to Upper Triassic, and Middle to Upper Jurassic, more or less silicified bedded limestone are widely present, both as parts of para-autochthonous successions and as redeposited blocks in ophiolitic mélanges. The studied, approximately 230-m-thick succession in the wider area of Zlatar Mountain, is one of the most important para-autochthonous sections in the Serbian part of the Dinaridic Ophiolite Belt. The succession is made up of an alternation of redeposited carbonate toe-of-slope deposits, sand to clay-sized siliciclastic rocks, hemipelagic mudstones and radiolarite–spongiolite basin facies. In the lower part of the sequence, the components of the siliciclastic beds were derived mostly from low- and medium-grade metamorphic rocks. Similar components, together with sand-sized fragments of ophiolitic rocks, were encountered in small amounts in some redeposited carbonate beds. The chronostratigraphic assignment of the succession is based mostly on foraminifers, but age-diagnostic radiolarians and other microfossil groups were also considered. In the lower part of the probably continuous succession, a Norian–Rhaetian assemblage was recognized; a Sinemurian–Pliensbachian assemblage was encountered up-section, whereas the upper part of the succession could be assigned to the Bajocian–Bathonian. Considering the paleogeographic reconstructions and the analogies of age-equivalent sections, the succession records the depositional history of the Bosnian Basin during the Late Triassic to Middle Jurassic period and may contribute to the understanding of the evolution of the Adriatic margin of the Neotethys Ocean in the transition interval from passive to active margin stages.

Jurassic melange complexes related to the subduction of the Neotethys Ocean occur in the Bukk Mountains, North Hungary. This paper characterizes the sedimentary sequence of basin and slope facies that occur in the southwestern part of the Bukk Mountains, placing special emphasis on the redeposited sedimentary rocks (olistostromes, olistoliths: Monosbel Group) in order to obtain information on the provenance of the clasts, and the mode and time of their redeposition. The series of formations studied shows a general coarsening-upwards trend. Based on radiolarians and foraminifera, the Monosbel Group formed in Early to Late Bathonian time. The lower part of the complex is typified by a predominance of pelagic carbonates, shale and radiolarite with andesitic volcaniclastic intercalations. The higher part of the succession is characterized by polymictic olistostromes. Large olistoliths that are predominantly blocks of Bathonian shallow marine limestone (Bukkzserc Limestone) appear in the upper part of the sequence. Based on the biostratigraphic and sedimentological data, results of analyses of the redeposited clasts and taking into consideration the concepts of the development of the western Neotethys domain, the evolutionary stages of the sedimentary basins were defined. The onset of the compressional stage led to initiation of nappe stacking that led to the formation of polymict olistostromes and then to the redeposition of large blocks derived from out-of-sequence nappes of the former platform foreland.

The paper summarizes the results of the latest sedimentological and stratigraphical investigations carried out on the Triassic and Jurassic basin and slope facies in North Hungary. The studies were performed in the Bükk Mts in the Darnó area, on cores drilled in the Mátra Mts, and in the Rudabánya Hills. The deep-sea succession of the Bükk commences with Early Bajocian radiolarite that is overlain by siliciclastic turbidites deposited in a submarine fan system. After this, the presence of hemipelagic carbonates-argillites interfingering with eupelagic radiolarites become typical. Pronounced tectonic activity during the Late Bajocian to Bathonian may have caused the deposition of polimyctic olistostromes. These are followed by the appearance of big olistolithes made up mostly of redeposited carbonates of platform origin (probably derived from the Adriatic Dinaridic Carbonate Platform). The relics of the Neotethys accretionary complexes occur in the Bükk, in the basement of the Mátra and also in the Darnó area. They show a good correspondence with those relics in the Dinarides and therefore their genetic conditions can be derived from the recently elaborated genetic models for the Dinarides. Although differences have been noticed in the composition of the olistostromes present in the Rudabánya Hills, compared to those in the Bükk and Mátra Mts, significant common features were also recognised.

The directly underlying sediments of the Recsk andesite stratovolcano contain characteristic Priabonian larger foraminifera and on their top the calcareous nannoplankton indicates the NP 21 zone marking about the vicinity of the Eocene/Oligocene boundary. Priabonian limestones of the neighbouring areas do not contain tuffaceous intercalations. Nannofossils of the above age also have been extracted from the intercalations of the lower part of the stratovolcanic andesite, and the older group of relevant radiometric ages detect similar ages (31–37 Ma). The first tuffs in the neighbouring territories appear in the lowermost Oligocene sediments. The younger group of relevant radiometric ages marks 27–30 Ma. Sediments directly overlying the andesite contain characteristic Oligocene larger foraminifera indicating most probably the basal part of the Chattian. Approximately the same age can be given based on the calcareous nannoplankton from the Kiscell clay just above the larger foraminiferal sediments. Tuffitic intercalations in the vicinity of Recsk can be followed throughout the Rupelian and up to about the first one-third of the Chattian. Thus, the polycyclic volcanic activity in Recsk lasted about 7 million years and seems to have been extending during the first two-third of the Oligocene from about 34 to 27 Ma. This interval covers practically the whole duration of the Kiscellian in the Central Paratethyan subdivision corresponding to the whole Rupelian and also to the first one-third of the Chattian. recsk_kotet_20080208.indd 59 2008.02.08. 20:01:02 György Less, Mária Báldi-Beke, Sarolta Pálfalvi, János Földessy, Botond Kertész 60

A program celja az eszak-magyarorszagi triasz es jura medence- es lejtőfaciesek szedimentologiai es retegtani vizsgalata volt uj fejlődestorteneti szintezis kidolgozasa erdekeben, es azert, hogy lehetőve valjon a korrelacio a Dinaridak es a Hellenidak hasonlo koru es kifejlődesű kepződmenyeivel. A kutatasokat a Bukkben, a darnoi teruleten, a Matraban melyitett furasok anyagan es a Rudabanyai-hegysegben vegeztuk. Az osszehasonlito elemzes erdekeben terepi megfigyeleseket es vizsgalatokat vegeztunk a Dinaridakban, a Hellenidakban, a Keleti- Alpokban es a Nyugati-Karpatokban. A Neotethys akkrecios komplexumanak reszet kepező bukki, tovabba a Matra aljzatat alkoto es a Darno kornyeki kepződmenyek alapvető jellegei jol megfeleltethetők a Dinaridakban ismertekkel, es ennel fogva kepződesi korulmenyeik is levezethetőek a Dinaridakra a kozelmultban kidolgozott modellekből. A Rudabanyai-hegysegben megismert olisztosztromak tormelekanyaga mutat ugyan osszetetelbeli eltereseket a bukkiekhez es a matraiakhoz kepest, de fontos osszekapcsolo belyegeket is felismertunk. Az Eszaki Meszkőalpokban megfigyelt szubdukciohoz kothető jelensegek szedimentologiai jellege es időbeli lefolyasa jo korrelaciot mutat a Bukkben megismerthez, de a medencekben felhalmozodott tormelekben lenyeges elteresek vannak. Ez az akkrecios komplexum tormelekanyaganak zomet szolgaltato felső, kontinentalis lemez felepitesenek kulonbsegere vezethető vissza. Az eredmenyek alatamasztjak a bukki, a matrai-darnoi es a rudabanyai mezozoos osszleteknek a Dinaridakhoz kapcsolodo eredeti helyzetet. | Study of sedimentological and stratigraphical characteristics of the Triassic and Jurassic basin and slope facies in North Hungary was the aim of the project. Elaboration of a new geodynamic synthesis and correlation with the coeval and genetically similar formations of the Dinarides and Hellenides were also in the focus of the project. The studies were performed in the Bukk Mts., in the Darno area, on cores drilled in the Matra Mts., and in the Rudabanya Hills. For comparative analyses field studies were carried out in the Dinarides, Hellenides, in the Eastern Alps and Western Carpathians. Basic characteristics of the relics of the Neotethys accretionary complexes occur in the Bukk, in the basement of the Matra and also in the Darno area show good correspondence with those in the Dinarides and therefore their genetic conditions can be derived from the recently elaborated genetic models for the Dinarides. Although differences were pointed out in the composition of olistostromes encountered in the Rudabanya Hills, and that in the Bukk and Matra Mts., significant common features were also recognised. Sedimentological characteristics and timing of the subduction-related phenomena observed in the Northern Calcareous Alps can also be correlated with those in the Bukk, but there are substantial differences in the composition of the clasts. This can be explained by the differences in the upper continental plate, source of dominant part of the clasts of the accretionary complex. The results support the concept on the Dinaridic relationship of the Mesozoic complexes of the Bukk, Matra-Darno and Rudabanya Hills.

Re-assessment of several key drill cores has revealed the existence of three tectonostrati- graphic units in the pre-Tertiary basement of Recsk-Darno Hill area, two of them representing the continuation of the units of Bukk Mts. The Bukk Parautochthon Unit is evidenced by the Up-

Kutatasi programunk celja az volt, hogy kepet nyerjunk a paleozoikum es a mezozoikum hataran lejatszodo, a fanerozoikum legnagyobb kihalasahoz vezető kornyezeti valtozasok pontos meneteről es ennek alapjan megkisereljuk az okok feltarasat is. A bukki szelvenyek vizsgalata soran biosztratigrafiai modszerekkel tisztaztuk a hatar pontos helyzetet, reszletes mikrofacies-elemzest vegeztunk. Kimutattuk, hogy a legfelső perm retegekben a karbonatkivalaszto szervezetek maradvanyai rovid szakaszon belul, de fokozatosan tunnek el. A maradvanyok eltűnesevel egyutt kezdődik el a delta 13C ertekek fokozatos eltolodasa negativ iranyba. Az ezt kovető szakaszt elszegenyedett fosszilia-egyuttes es litologiai valtozas (hatar marga) is jellemzi. A tulelő permi szervezetek eltűnese egybeesik a delta 13C ertekek negativ csucsaval, amit a P-T hatar kemosztratigrafiai jelzőjenek tekintenek. Negativ eltolodas az erős vizmozgasu sekelytengerben kepződott dunanuli-kozephegysegi retegsorok ooidos hatarszakaszan is egyertelműen kimutathato. A triasz kezdeten mikrobas karbonatok, illetve a sekely, erős vizmozgasu szubtidalis ovezetekben oolit retegek kepződese jellemző. Az eredmenyek bebizonyitottak, hogy a Balvany-eszak elnevezesű alapszelveny a perm es a triasz hataran lezajlott esemenyek megismerese szempontjabol az egyik legteljesebb es a legjobban tanulmanyozhato szelveny Europaban es vilagviszonylatban is kiemelkedő jelentősegű. | The aim of the research project was to contribute for better understanding of environmental changes, which resulted in the largest extension of the Phanerozoic at the boundary between the Paleozoic and Mesozoic. Applying biostratigraphic methods, the exact position of the boundary was determined in the sections of the Bukk Mountains and detailed microfacies analyses were carried out. It was proved that in the uppermost Permian layers, remnants of carbonate secreting organisms gradually disappear in a short interval. A negative shift of delta 13C values starts at the level of onset of gradual decrease in the amount of bioclasts. The next interval is characterised by an impoverished fossil assemblage and also a change in the lithology ('boundary shale'). Disappearance of the 'survivor' Permian biota coincides with a negative delta 13C peak that is considered as the chemostratigraphic marker of the Permian-Triassic boundary. The negative shift was also encountered in the oolitic boundary interval of the Transdanubian Range, which was deposited in a high-energy shallow marine environment. In the earliest Triassic formation of microbial carbonates on the low-energy sea-bottom and oolites in the high-energy environments was typical. Results of the project evidenced that the Balvany-North section is one of the most complete and best-exposed Permian-Triassic boundary sections in Europe and it has an outstanding importance world-wide.

The basement of the Pannonian Basin is made up of tectonostratigraphic terranes of varying origin. They gradually amalgamated to form the large Alcapa and Tisza-Dacia composite terranes that were juxtaposed during the Tertiary. In North Hungary, in the basement of the Tertiary volcanic complex of the Matra Mts and in the western part of the Bukk Mts, remnants of a Jurassic accretionary wedge were encountered. Ore exploration boreholes encountered several hundred-meter thick carbonate and siliceous shale-radiolarite successions in the basement of the Matra Mts (Darno Complex). Based on detailed studies of Core Recsk-109, the carbonate succession consists predominantly of grainstone with packstone-wackestone intercalations. Peloidal bioclastic grainstone is the most common texture type but sand-sized intraclasts and oncoid and ooid grains also occur locally. The most spectacular feature is the large amount of coarse to medium sand-sized fragments of calcified cyanobacteria ("Porostromata"). Platform-derived...

In the Bukk Mountains the Upper Permian is represented by the Nagyvisny6 Limestone, which contains very rich marine assemblages. It is overlain by the Gerennavar Limestone (uppermost Permian-Lower Triassic) which records the effects of the Permian-Triassic mass extinction with a dramatic decrease in diversity and abundance of fossils. The basal Gerennavar Limestone is represented by a clayey marl unit (basal beds) deposited in a quiet, low-energy marine environment below the storm wave-base, whose maximum thickness, about one meter, is recorded in the Balvany-North section. From this locality a relatively diversified and abundant marine benthonic assemblage has been collected, and is here described. Bivalves are represented by: Bakevellia cf. ceratophaga (Schlotheim),? Pterinopectinidae gen. et sp. indet., Eumorphotis lorigae sp. n., the most abundant species, Entolium piriformis (Liu) and Pernopecten latangulatus Yin. Brachiopods are less frequent, and the following four species have been identified: Spinomarginifera sp., Ortbothetina ladina (Stache), Ombonia tirolensis (Stache) and Orbicoelia tschernyschewi (Likharew). An exact age of this fauna, based on conodonts, is not yet available, but the strong affinities with those of the lower Tesero Member (Dolomites) and the Lower Kathwai Member (Pakistan) suggest a latest Permian age (? pracparvus Zone). If so, the Balvany-North section becomes one of the few in the world which records the last bioevents of the Palaeozoic.

The Permian/Triassic boundary was recognized in continuous marine successions in several outcrops in the Bükk Mts, North Hungary and in a few core sections in the northeastern part of the Transdanubian Range. In the Bükk Mts, of four studied boundary sections only two proved to be complete. They represent an outer ramp setting. In these sections the topmost Permian is made up of dark gray limestone, rich in fragments of crinoids, calcareous algae, mollusks, brachiopods, ostracods, and foraminifera. There is a dramatic decrease in the amount of the bioclasts in the last two limestone layers, which are overlain by a 1 m-thick shale bed. The lower two-thirds of this bed still contain Permian fauna but its upper part is almost free of bioclasts. The overlying platy limestone contains a pauperized fossil assemblage indicating stress conditions. The two core sections studied in the Transdanubian Range represent an inner ramp setting. The uppermost Permian is made up of lagoonal-sabkha cycles. It is overlain by subtidal packstone-grainstone, rich in Late Permian fossils. Oolitic facies characterizes the boundary interval. Onset of ooid formation was probably the consequence of biotic decline leading to cessation of skeletal carbonate production. Along with oolite beds, stromatolites, micrite with "microspheres" and fine siliciclastic microlayers characterize the basal Triassic succession, reflecting overall stress conditions and the changing energy of the depositional environment.

This paper presents the Lower Triassic sequence in the Bukk Mountains (NE Hungary). On the basis of the revised macrofossil-collections and previous conodont studies, a biostratigraphic correlation and a chronostratigraphic subdivision of the formations and members is given. Hindeodus parvus (Kozur et Pjatakova), Isarcicella isarcica (Hukriede), Claraia aurita (Hauer), Eumorphotis gr. multiformis (Bittner), Eumorphotis cf. hinnitidea (Bittner), Costatoria subrotunda (Bittner), Eumorphotis kittli (Bittner), Tirolites illyricus Mojsisovics, Tirolites seminudus Mojsisovics, Costatoria costata (Zenker), Rectocornuspira kalhori Bronnimann, Zaninetti et Bozorgnia, Cyclogyra? mahajeri Bronnimann, Zaninetti et Bozorgnia, and Meandrospira pusilla (He) are the main index fossils. Two sections, which represent the entire Lower Triassic succession, were studied from a sedimentological point of view. These are the Gerennavar section for the Gerennavar Limestone Formation, and the Lillafured section for the Ablakoskovolgy Formation, respectively. The sedimentological data and facies interpretations are summarized in facies models. During Early Triassic time the depositional area of the Bukk Mountains were situated in the epeiric shelf of the Western Tethys. The model of the Gerennavar Limestone Formation reflects the high-energy, tide- and wave-dominated shallow shelf, characterized by a protected-stabilized muddy sand flat and a high-energy sand belt. The. model of the siliciclastic, lower part of the Ablakoskovolgy Formation indicates a mixed, dominantly siliciclastic shallow shelf with deposition in the coastal, shoreface and transitional zones. The model of the carbonate, upper part of the Ablakoskovolgy Formation refers a storm-controlled shelf with facies representing the whole spectrum from the peritidal-shallow shoals to the low-energy deeper subtidal zone below the storm wave-base. Lithologic and facies comparison of the Lower Triassic succession of the Bukk Mountains to other sequences of the Western Tethyan depositional area reveals many differences, and fewer similarities, which suggests local controls on depositions, that is locally different terrigenous siliciclastic input, different subsidence rate, antecedent topography, and dominance of the local physical regime.

Results of the Hungarian-Serbian cooperation aiming the correlation of Upper Palaeozoic - Triassic series of the Bükk (N Hungary), Jadar (NW Serbia) and Sana-Una (NW Bosnia) terrains are summarised in Hungarian, previously presented in English in PROTIĆ et al. (2000) and in FILIPOVIĆ et al. (2003). Comparison with the classical Upper Palaeozoic sequences of the Carnic Alps (Austria/Italy, previously presented in EBNER et al. 1991, 1998), is also taken into account. A number of obvious similarities (which represent real pecularities in the Circum-Pannonian region) can be recognised: marine development of the Late Carboniferous (with typical Palaeotethyan fusulinids) and of the Permian, marine Permian-Triassic passage, etc. From the Middle Permian to the Late Triassic the Jadar Block and Bükkium terraines show a practically identical development: presence of Bobova Breccia (as equivalent of the Tarvisio Breccia) at the base, almost the same Middle Permian to Lower Triassic, Sebesvíz-type conglomerate on top of Anisian platform dolomites, Ladinian early rift type andesitic volcanism, etc. Main characteristics are also correlatable with the Carnic Alps, but with more pronounced local differences. Palaeogeographically it can be concluded, that the three terraines involved into the present correlation were located originally very close, or even adjacent. The Sana-Una Terrain practically remained in situ and became later involved into the Dinaridic nappe system.