Authors:Ádám Bede, Roderick B. Salisbury, András István Csathó, Péter Czukor, Dávid Gergely Páll, Gábor Szilágyi and Pál Sümegi
Studies. An Environmental and Archaeological Multiproxy Study of Burial Mounds in the Eurasian Steppe Zone . British Archaeological Reports, International Series 2238, Archaeopress , Oxford , pp. 71 – 131
Authors:Georgina Lukoczki, Tamás Budai and Tibor Németh
Sideritic—kaolinitic and green clay layers were previously reported from the Mecsek Mountains (SW Hungary) as indicators of Tethyan volcanism in the otherwise germanotype Middle Triassic succession. The aim of the present study is to provide a review and a critical re-evaluation of the previously published data on both the sideritic—kaolinitic layers (the so-called “Mánfa Siderite”) and the green clay layers. New results of mineralogical investigation of the green clay layers are also presented. The Middle Triassic volcanic origin of the “Mánfa Siderite” cannot be confirmed. In addition to a possible volcanic contribution, the sideritic—kaolinitic layers were probably formed in a freshwater swamp under humid, tropical climatic conditions, whereby weathering in an organic-rich, acidic environment led to the formation of “underclays” and siderite in the coal-bearing formations of Late Triassic to Early Jurassic age. These layers were probably tectonically placed over Middle Triassic carbonates. The illitic green clay layers intercalated in the Middle Triassic dolostone may represent terrigenous deposits, and the illite mineralogy probably is the result of burial diagenesis of detrital clays.
Authors:Márton Bauer, Tivadar M. Tóth, Béla Raucsik and István Garaguly
migration, it is suggested that the carbonaceous material records the maximum temperature reached during burial, and the large pyrite crystals grew in the course of the uplift following oil migration to the reservoir.
There are several subsequent
Buried soils are grouped into three categories, namely Holocene soils, Pleistocene ones and those of earlier geologic periods. Buried soils mainly occur on floodplains and in sandy areas in Hungary. Gradual subsidence of the lowland areas and irrationally high rate of deforestation in the catchment regions have resulted in the burial of soils with younger deposits in the floodplain areas; most of the soils buried here are black hydromorphic ones. The major cause of burial in the sandy areas, however, is repeated deposition of the shifting sand. Climatic changes and the beginning cultivation of the originally grassland and forest areas have resulted in the movement and redeposition of the sandy deposits. Most of the Pleistocene-age paleosols have come to light in loess profiles. They can be regarded as remnants of forest soils with varying humus profiles and serve as excellent stratigraphic markers in studies of loess deposits.
Authors:Chris Balzotti, Charles Golden, Andrew Scherer and Richard E. Terry
Stable C isotope studies of the soil organic matter (SOM) have delineated areas with histories of vegetation change from C3 forest to C4 maize (Zea mays L.) agriculture and back to the contemporary C3 forest. The objectives of this study were to: (1) determine if land around El Kinel, Guatemala possessed a vegetative history of shifts from C3 forest to C4 maize agriculture in the past, (2) determine if 10 years of contemporary maize production is sufficient time to deposit an isotopic signature of C4 plants in the root zone (top 40 cm), and (3) to examine the extractable phosphorus concentrations and δ13C in soils of important archaeological features that included a midden, a burial, and two ancient reservoirs (aguadas). The lack of a shift in δ13C greater than 3.5‰ in the top 40 cm of the contemporary maize field suggested that continual maize cultivation of more than ten years is required to create an isotopic signature for maize agriculture. Carbon isotopic evidence was found in soil profiles to confirm that long-term agriculture was practiced by ancient Maya farmers at El Kinel. The man-made aguadas did not show isotopic shifts greater than 2.3‰ in any part of the profile, indicating they were used for other purposes not associated with C4 plant growth. The relatively low P (<30 mg kg−1) was found in soil at the same depth but at a distance of 30 cm from an ancient burial. The high P concentration (127 mg kg−1) found within millimeters of the bones implied that the P enrichment came from the remains but P remained fixed in the soil and did not migrate.
Authors:Barbara Szabó, Tivadar M. Tóth and Félix Schubert
Volcanic successions of the Kecel Basalt Formation (KBF) occur in the southern part of the Pannonian Basin. As a result of periodic submarine eruptions, the basaltic and pyroclastic rock horizons were intercalated with layers of the Late Miocene Endrod Marl Formation, which is regarded as one of the most important hydrocarbon source rocks in the area. The KBF was discovered through almost 30 wells between 2,200 and 2,900 meters of depth. Due to the high fracture porosity, some parts of the formation show good reservoir characteristics and act as important migration pathways of hydrocarbon-bearing fluids. Since the reservoir is presumably fracture-controlled, this study concentrates on the evolution of fractures crosscutting the rock body. Based on textural and mineralogical features, four distinct vein types can be distinguished, of which the first three types are discussed in this paper. Beside calcite, quartz, feldspar, and chlorite, the veins are cemented by various zeolite minerals. The vertical dimension of the dominant zeolite zone indicates the burial-diagenetic type of zeolite zonation and suggests subsidence of the subaqueous basalt after formation.
Authors:Tibor Zelenka, Endre Balázs, Kadosa Balogh, János Kiss and at. al.
Surface Neogene volcanics in Hungary are abundantly documented in the literature, but buried volcanic structures are little known. Early burial of the volcanic centers beneath latest Miocene to Pliocene sediments preserved much of their original relief, permitting their classification into genetic types. More than two-thirds of Hungary is covered by thick Neogene and Quaternary sediments, below which buried volcanic eruptive centers and the extent of their products may only be recognized by complex geologic-geophysical methods. Our study is based on the data of several thousand wells, more than 60,000 km of seismic sections, as well as airborne and surface geophysical (gravimetric, magnetic, electromagnetic, radiometric) data. Results of chemical, mineralogical studies and K/Ar dating of deep cores were also included. The data were evaluated in terms of the regional deep structure of the Carpathian-Balkan region, the Miocene evolution of which was determined by the position, movement and welding of individual microplates. Integration of all available data reveals that the Miocene volcanic centers are concentrated near microplate boundaries. In the volcanic centers the lavas and pyroclastic deposits far exceed 50 m in thickness. The data show that the buried volcanic rocks below the Transdanubian region (Little Hungarian Plain and Somogy-Baranya Hills), the Danube-Tisza Interfluve and the Great Hungarian Plain extend over a much larger area than do the outcropping volcanoes in Northern Hungary (from the Visegrád to the Tokaj Mts). In the southern part of Transdanubia (W. Hungary) a major calcalkaline, rhyolitic, ignimbritic event took place early, in Eggenburgian and Ottnangian (Early Miocene) times. The centers and tuff sheets of this volcanic event can be traced from the Mecsek Mts to the Salgótarján Basin, the southwestern Bükk Basin and the central part of the Great Hungarian Plain. This event was followed by andesitic volcanism. The rhyolite and dacite volcanic centers of Karpatian age are predominantly situated in Transdanubia, whereas the Badenian (Mid-Miocene) andesite and dacite series of large stratovolcanoes are buried below southern Transdanubia, the Danube-Tisza Interfluve and the Great Hungarian Plain. In Sarmatian and early Pannonian (Late Miocene) times, pyroclastic sheets several thousand meters thick and lava domes were formed; they are predominantly rhyolitic, subordinately andesitic and dacitic, and are situated in the eastern part of the Great Hungarian Plain (Nyírség). With the end of microplate motion, as the plate consolidated in the late Miocene, thick but areally restricted alkali-trachite (Little Hungarian Plain) and alkali-basalt lava domes and tuff craters formed in the Little Hungarian Plain, Transdanubia and the Danube-Tisza Interfluve.