Ede Hertelendi

Geochronologic and paleoclimatic characterization of Quaternary sediments in the Great Hungarian Plain.

We reconstructed the climate of the Great Hungarian Plain between the years, 7-32 ka BP using a malacothermometer method. The reconstruction is based on seven Gastropoda taxa, for which optimal temperature and tolerance ranges have been determined. The temporal scales of the malacofaunal levels were calibrated with radiocarbon data. We compared our paleotemperature values with the temperature values of existing climatic curves and found the same climatic periods.

Hydrogen index as reflecting intensity of sulphidic diagenesis in non-bioturbated, shaly sediments

Abstract Based on 13 published porewater H 2 S and sulphate profiles the amount of H 2 S escaping from non-bioturbated shales varies between some few % to 45% of the amount of bacterially generated H 2 S. This finding permits calculation of the original organic carbon (TOC or ) content of immature nonbioturbated shales using TOC and sulphur content data. In two immature non-bioturbated sequences from Hungary (Toarcian and Oligocene) the first-order correlation between HI and TOC/TOC or was found to be stronger than that between HI and TOC, indicating that sulphate reduction was the leading process both in decrease in TOC content and degradation of kerogen source potential.

Estimation of primary productivity in the Toarcian tethys- A novel approach based on TOC, reduced sulphur and manganese contents

Abstract About 60 samples from the non-bioturbated Urkut Manganese Ore Formation (Bakony Mountains, Hungary), representing the early Toarcian anoxic event, were studied for: (1) TOC content, Rock-Eval parameters and kerogen δ 13 C; (2) S content and δ 34 S and (3) Al, Ca, Mn, Si and Ti contents. Using the example of the formation, a novel approach for estimating paleoproductivity is presented, taking into account reduced sulphur and manganese contents, which reflect the amount of organic carbon lost during early burial. Drastic changes in Mn content (between 0.7% and 37%) during deposition of the formation resulted in very variable early diagenetic processes, with sulphate reduction dominating in low-Mn sediments, and Mn reduction dominating in high-Mn sediments. The amounts of reduced sulphur and manganese allowed calculation of the original organic carbon (TOC or ) content throughout the formation. Based on stratigraphic variations in chemical composition, changes in the rate of sedimentation were assessed for the three main members of the formation. Next, using the formula describing the relationship between measured productivity, rate of sedimentation and carbon flux reaching the sea-floor, developed by Suess (1980) , past productivity was calculated. The values obtained, lower than those prevailing in present-day upwelling systems, are probably underestimated because of uncertainties of chronostratigraphic and water-depth data. However, relative differences between productivity values obtained for the three members are considered as realistic and suggest an increase in productivity during deposition of the formation. This increase is not related to stratigraphic variations in Mn content and is accompanied by an increase in the growth of calcareous plankton.

Reconstruction of microenvironmental changes in the Kopasz Hill loess area at Tokaj (Hungary) between 15 and 70 ka BP

We collected 11 Kopasz Hill loess profiles for paleoecological and geochronological analysis. The loess accumulation and development formed during the last (Weichselian) glacial period between 70 and 15 ka BP. We found that the majority of the loess profiles were composed of three typical loess strata and two well-developed paleosol horizons. Based on vertebrate remains, the lowest loess layer formed between 70-50 ka BP, during the first cool and dry climatic phase of the last glacial period, when forest steppe vegetation dominated in the Kopasz Hill area. On the surface of the lowermost layer, a paleosol developed between 50 and 40 ka BP as an indication of a more humid and warmer climatic phase. This paleosol layer was buried by a new loess layer that developed between 40 and 32 ka BP. The upper paleosol horizon developed between 32 and 26 ka BP. Molluscs preferring a mild climate were found in this layer, suggesting that this phase was wet and relatively temperate. A number of fired macrocharcoal remains can be found on the top of this paleosol layer. Charcoal samples from nine sites were dated by radiocarbon analyses. These results reflect the presence of a charcoal-rich horizon that developed 28-26 ka BP. Ca. 26 ka BP, loess formation resumed. We analyzed 14 samples from 6 sites by the (super 14) C method. Based on (super 14) C data, the uppermost part of loess profiles developed between 26 and 15 ka BP.

Concentration of radiocarbon and its chemical forms in gaseous effluents, environmental air, nuclear waste and primary water of a pressurized water reactor power plant in Hungary

We measured airborne releases of 14C from the Paks Pressurized Water Reactor (PWR) Nuclear Power Plant (NPP).Ttvo continuous stack samplers collect 14C in 14C02 and 14CnHm chemical forms. 14C activities were measured using two techniques; environmental air samples of lower activities were analyzed by proportional counting, stack samples were measured by liquid scintillation counting. 14C concentration of air in the stack varies between 80 and 200 Bqm-3. The average normalized yearly discharge rates for 1988-1993 were 0.74 TBqGW11yy-11 for hydrocarbons and 0.06 TBqGW11yy-11 for CO2. The discharge rate from Paks Nuclear Power Plant is about four times higher than the mean discharge value of a typical Western European PWR NPP. The higher 14C production may be apportioned to the higher level of nitrogen impurities in the primary coolant. Monitoring the long-term average excess from the NPP gave D14C = 3.5%o for CO2 and D14C = 20%o for hydrocarbons. We determined 14C activity concentration in the primary coolant to be ca. 4 kBq liter-1. The 14C activity concentrations of spent mixed bed ion exchange resins vary between 1.2 and 5.3 MBgkg-1 dry weight.

Re-Evaluation of the Neolithic in Eastern Hungary Based on Calibrated Radiocarbon Dates

The chief objective of this paper is to improve our understanding of the Neolithic in Eastern Hungary using absolute chronological data. To accomplish this we calibrated new measurements as well as previously published dates. The up-to-date, standardized evaluation of 261 calibrated measurements showed temporal overlaps between archaeological cultures defined on the basis of ceramic styles. The increasing number of dates suggest that the Neolithic period began at the turn of the 6th and 7th millennia BC and lasted for ca. 1500 yr in the present area of the Great Hungarian Plain (Alfold). Further research should be aimed at complementing the current data set with dates from western Hungary and establishing additional correlations among stratigraphic, typological and radiocarbon dates.

Duration of tell settlements at four prehistoric sites in Hungary

The chief objective of this paper is to improve our understanding of the Neolithic in eastern Hungary using absolute chronological data. To accomplish this we calibrated new measurements as well as previously published dates. The up-to-date, standardized evaluation of 147 calibrated measurements showed temporal overlaps between archaeological cultures defined on the basis of ceramic styles. The average timespan of tell settlements of 285 yr was obtained using radiocarbon dates from four major settlements in eastern Hungary: Berettyoujfalu-Herpaly, Hodmezovasahely-Gorzsa-Cukortanya, Ocsod-Kovashalom and Polgar-Csoszhalom.

Radiocarbon Chronology of Late Neolithic Settlements in the Tisza-Maros Region, Hungary

We investigated chronological questions of five Late Neolithic settlements in the Hungarian Tisza-Maros region. Fifty new radiocarbon dates provide an internal chronology for the developmental phases of the tell settlements, and place them into the wider framework of the southeastern European Neolithic. An example is presented of how a unique type of stratigraphic excavation helps the interpretation of radiocarbon data, which are in contradiction with the stratigraphic position of the samples.

Sources of random error in the Debrecen radiocarbon laboratory.

ABSTRACT. A new high-pressure methane-filled counter system for 14C dating was installed in 1986 when the first stage of the International Collaborative Study (ICS) started. Random errors in the new measuring system and in the process of chemical pretreatment and preparation were checked during the three years of intercomparison. Results show that the most important source of error in our laboratory is gas contamination. This causes variation of the count rate to exceed the statistically expected variability. Other sources of error are also discussed and limits of their contributions are given.

Isotope Investigation of Lake Vrana and Springs in the Kvarner Area

From the strong enrichment of 2H and 18O in the water of Lake Vrana (Cres Island, Croatia) we concluded that there is negligible outflow from the lake. Regional recharge could be of minor importance since the amount of local precipitation is about the same as that of evaporation from the surface and there is no major outflow. From the existing isotope data no evidence was found of an inflow of fresh karstic water in the deepest part of the lake. Mean residence times of 30–40 years were obtained for water in the lake if the enrichment of tritium due to evaporation is taken into consideration. At the same time, the homogeneity of the isotope results indicates good mixing of this deep karstic reservoir. Seven springs were sampled in the Rijeka region and residence times between 5 and 10 years were calculated for the water contained in them.