Mecsek Mountains Research Articles

Sun and shade leaves? Cuticle ultrastructure of Jurassic Komlopteris nordenskioeldii (Nathorst) Barbacka

An ultrastructural transmission electron microscope (TEM) study of fossil leaf cuticles from the Jurassic pteridosperm Komlopteris nordenskioeldii (Nathorst) Barbacka from the Mecsek Mountains (South Hungary) was conducted. Remnants of cuticles of leaves originating from so-called “sun and shade” environments were sectioned with a diamond knife, transversally as well as longitudinally. Although the present study showed a simple type of cuticle in this pteridosperm, differences were observed in the occurrence of its components, such as electron lucent amorphous material and various densities of granules, which give rise to different zones. The included fibrilous elements appeared to be made of aggregated and aligned granules, equivalent in size and electron density to nearby non-fibrilous granular regions. The combinations of these ultrastructural features allow distinctions between four types of cuticle: sun upper, sun lower, shade upper and shade lower. Considering the distinction made earlier in two types of cuticle and supposed to be related to sun and shade on the basis of macroscopical and microscopical features, four types only on the basis of differences in thickness, the present study reinforces the distinctions with ultrastructural microcharacteristics. As this study shows the variations in ultrastructure of cuticle among the four types, the differences observed may reveal the great sensitivity of some plants to environment. At the same time, it points out the importance, in ultrastructural studies of cuticles, of studying a number of samples for one taxon.

Slingram Measurements in the Mecsek Mountains, Hungary

The so-called Slingram measurements form a family of frequency-domain electromagnetic methods, when the transmitter is a vertical magnetic dipole, and the vertical component of the magnetic field is measured, at some distance from the transmitter. The measured value is usually the imaginary (out-of-phase) part of the vertical magnetic field component. Such an equipment was manufactured at the University of Neuchâtel (Switzerland) and supplied to the Geodetic and Geophysical Research Institute in frame of a Swiss-Hungarian co-operation, supported by the Swiss National Research Foundation. As a part of test measurements, Slingram profilings and soundings were carried out for exploration of karstic water reservoirs connected to tectonically weak zones in the Mecsek Mountains, close to Pecs (Hungary). One-dimensional inversion and comparison with other geo-electromagnetic techniques as radio-magnetotellurics (RMT) and radiofrequency-electromagnetics (RF-EM) resulted in good and interpretable results.

The Stomatal Ontogeny and Structure of the Liassic Pteridosperm Sagenopteris (Caytoniales) from Hungary.

Stomatal ontogeny is often inferred but rarely documented for extinct fossil plants because it requires observations from young leaves that are rarely preserved as fossils. The discovery of several very young leaves of the Jurassic plant Sagenopteris (Caytoniales) in the Mecsek Mountains (southern Hungary) in a good state of preservation provides the opportunity for studying the stomatal ontogenesis of this genus. The specimens show perigenous anomocytic stomata. This feature confirms the evolutionarily high position of Sagenopteris among fossil gymnosperms and supports the opinion that the ancestors of angiosperms and some groups of pteridosperms might be closely related. Such clear examples of stomatal development have not previously been documented for fossil material.

Multistage evolution of a volcanic suite in the Eastern Mecsek Mountains, Southern Hungary

This paper proposes a magmagenetic model for the Lower Cretaceous volcanic rocksuite from the Eastern Mecsek Mountains in Southern Hungary based on both major and trace element analysis as well as mineralogical investigations.

Vestiges of atoll-like formations in the Lower Cretaceous of the Mecsek Mountains, Hungary

Macro- and microfossils and microfacies of a few Lower Cretaceous sections in the Mecsek Mountains have been studied. Twenty five species of corals are reported for the time first from the Hungarian Cretaceous. Fossils derived from the carbonate platform are often found together with those of pelagic origin and monomictic volcanoclastics, indicating a special sedimentary environment. Based on this study the following model is proposed for the Early Cretaceous geological history of the Mecsek Mountains: instead of overall uplift and erosion giant basalt volcanoes grew above sea level until the Valanginian, whilst bathyal conditions were preserved between them. The volcanoes were bordered by gravel beaches, then sandy and silty lagoons, and the edge, of submarine slopes were crowned by atoll-type build-ups. Fossils and rocks of different environments were transported down the slopes of the volcanoes and mixed. As a result of widespread erosion during the Late Cretaceous or Palaeogene only the basal parts of a few volcanoes are preserved.

Geochemistry and petrogenesis of the Early Cretaceous continental rift-type volcanic rocks of the Mecsek Mountains, South Hungary

Early Cretaceous volcanic rocks (basanite to phonolite) from the Mecsek Mountains (South Hungary) represent the products of Late Mesozoic extension-related alkaline magmatism at the southern margin of the European plate. Two mafic groups have been distinguished: ankaramite-alkali basalt and Na-basanite-phonotephrite. Phonolites could have been formed from the Na-basanitic magma by low-pressure fractionation. The major and trace element characteristics of the Mecsek basalts are similar to those of alkaline basalts of other intraplate areas and have a St. Helena-type OIB affinity. The mantle source of the Mecsek volcanics could be similar to that proposed by Wilson and Downes (1991) as one of the mantle endmembers for extension-related Tertiary-Quaternary alkaline basalts in Europe. Geochemical modelling indicates that the primary magmas of the Na-basanite series were formed by about 4% partial melting, whereas ankaramites and alkali basalts originated by about 6% partial melting of a garnet-peridotite source.

Comparative palaeoenvironmental modelling of Buntsandstein braided river evolution in Bulgaria and Middle Europe

The Buntsandstein in Europe was deposited in various independent basins which are situated up to several thousands of km apart. The basins of the German facies are located in Middle Europe, Spain, and Bulgaria, whereas the Buntsandstein areas in Hungary, Austria and neighbouring countries belong to the Alpine facies, and the Tatra Mountains in Poland represent the Carpathian facies. While the Mid-European Triassic Basin has a very large extension, Bulgaria is characterized by comparatively smaller basins. The Buntsandstein columns in the Triassic basins in Bulgaria exhibit a pronounced similarity of the evolution of fluvial style to that in the Mid-European Buntsandstein. Characteristic lithogenetical elements such as blue-violet calcrete palaeosols, aeolian dune sands and Brӧckelbank carbonate breccias allow a palaeoenvironmental correlation of the Buntsandstein in Bulgaria with that in Middle Europe. The megacycles of the evolution of fluvial style thus permit a large scale lithostratigraphic connection of the Buntsandstein in both areas. The most important Buntsandstein basins in Bulgaria are Teteven Anticlinorium, Iskar Valley, Vitoša Mountains, Belogradčik area, Petrohan Pass, Sviti Ilija Heights and Trojan Pass. The Buntsandstein profiles in these basis are in parts of the sections quite comparable to those in Eifel-Pfalz-Saar area and Upper Franconia/Oberpfalz (Germany FRG), Holy Cross Mountains (Poland), Sudetes (Poland and Czechoslovakia. Mecsek Mountains (Hungary) and South Devon (England) in the Mid-European Triassic Basin and adjoining areas. Significant examples of the comparability of the evolution of fluvial style and palaeoenvironmental history of the Buntsandstein over long distances between Bulgaria and Middle Europe include Iskar Valley (Bulgaria) and Eifel Saar area (Germany, FRG), with various parts of the Eifel thus being the closest comparable examples to most of the Bundsandstein successions in Bulgaria. The Buntsandstein in Bulgaria can in most areas be stratigraphically divided into lower conglomerates, Middle Sandstones, Upper Sandstones and Mudstones, and terminal Mudstones. The boundary between Middle Sandstones and Upper Sandstones and Mudstones can be correlated with the boundary Middle Upper Buntsandstein in the German Basin.

Tectonic rotations south of the Bohemian Massif from palaeomagnetic directions of Permian red beds in Hungary

Palaeomagnetic studies were carried out in Permian red beds of the Balaton Highlands, the Mecsek Mountains and the Bükk Mountains of Hungary. Statistically well defined directions were obtained from six localities in the Balaton Highlands and two localities in the Mecsek Mountains. No meaningful results were obtained from the Bükk Mountains. Three magnetic components were identified from red beds of the Balaton Highlands: (1) in haematite with a very high unblocking temperature (700°C), interpreted as a Permian magnetization ( D c= 79°, I c=−11°, k = 24, α 95 = 13.6 ° ), in six samples from three beds in a single locality (2) a secondary but ancient component residing mainly inmaghemite ( D = 314°, I = 49°, k = 48, α 95 = 10.0° ), in 84 samples from six localities with a within-locality scatter increasing on unfolding; and (3) a direction parallel to the present field ( D = 7°, I = 62°, k = 46, α 95 = 7.7 ° ), in nine samples from a single locality. For the Balaton Highlands, the component 1 direction agrees with directions obtained from Permian red beds and volcanics in the eastern part of the Southern and Eastern Alps and the Inner West Carpathians. All show large, apparent rotations relative to stable Europe since the Permian. Component 2 is of post-folding (post-Aptian) age. Its direction agrees with known Late Cretaceous directions from the Transdanubian Central Mountains, which also show significant counterclockwise rotation relative to stable Europe. The characteristic magnetization for the Mecsek Mountains resides in haematite and may be primary. The directions indicate only a slight net counterclockwise rotation of the Mecsek Mountains with respect to stable Europe since the Permian.

Coal petrographical characterization of the Mecsek bituminous coal basin, with special reference to the contact metamorphism of coal seams

The bituminous coals of the Mecsek Mountains were formed during the Early Lias and are of paralic origin. The limnic complex of the layers consists of sandstone, aleurite and coal, and the upper layer contains marl of marine origin. The 9–15 minable coal seams have a thickness of 1.2–14.0 m. The Mecsek Coal Field and the coal complex within it show a folded and fractured structure, and with regard to their mechanical behaviour, are strongly stressed. 75–90% of the coal material is vitrinite, and 1–14% is inertinite. The quantity of liptinite is smaller than 9%. The coal rank is that of gas coal and fat coal with a reflectivity of 0.85–1.5%, respectively. The coal rank differences and variations according to zones are the consequence of forces of various magnitude that occurred in the course of orogenic movements. During the Early Cretaceous, there was some under-sea-bed volcanic activity in this field, the diabasic material of which appeared in the form of a bed vein along the coal seams, and this has exerted a strong metamorphic influence on the coal. It has resulted in thermo-contact alteration, i.e. in the appearance of natural coke and semicoke of various degrees of metamorphism. This alteration badly affected the quality and technological characteristics, especially the cokability of the coal.

Microplankton of the neogene of Hungary

During the palynological researches in the Neogene deposits of the Mecsek Mountains (Hungary) some microplankton organisms were also found (Phylum Monadophyta: 54 species of 28 genera). The planktonic remains can be ranged among Diatoma, Dinoflagellata (partly Hystrichosphaeridae) and microorganisms of uncertain affinity. In the first place the plankton organisms are facial indicators. Secondly, the redeposited forms permit the drawing of conclusions as to the origin of the sediment.

Palynological study of the Neogene deposits of the Mecsek Mountains (Hungary)

In the course of the palynological analysis of samples taken from both vertical and horizontal sections across a series of Neogene basins around the Mecsek Mountains, 424 species of 185 genera were described. Palynological data made it possible to reconstruct the succession of subtropical vegetation patterns in relation to geological time units from the Helvetian to the Pannonian. The palaeoclimatological results deduced from each vegetation pattern suggest a change from the warm subtropical climate to a cold subtropical one, a change influenced by local and microclimatic factors. Besides permitting other conclusions to be drawn, the vegetation patterns also support the established stratigraphic subdivision.

Daten zur Kenntnis der Algenflora der Höhle Kölyuk von Mánfa

The Kolyuk cave lies in the southern part of Hungary in the Mecsek Mountains, about 3 km. in distance from the village of Mànfa. The material accepted for investigation originated from a recently discovered and until now completely entombed part of the cave. It was collected by the geologist Gàbor Magyari and consisted of material scraped from the walls and ceiling of a cavity in the cave, which could be reached only by underwater swimming. From these scrapings cultures were installed with sterile Knopp solution and after the algae present in the collection reproduced, a diversified flora developed which consisted of the following: Cyanophyta - 20 species, varietates and formae; Bacillariophyta - 2 species and varietas; Chlorophyta - 7 species. There was a total of 29 different taxa. Since the cave from which the collections were made was completely devoid of light, it is especially significant that a well developed blue-green algal flora was found. We thus have further evidence for our previously advanced theory (Claus, 1955, 1962 a, 1962b) that some algae were present in the caves at the time of their origin. They were able to survive in an actively assimilating vegetative state and not only in the form of cysts or arthrospores.