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Abstract

The 13.5 Ma Harsány ignimbrite, in the eastern part of the Bükkalja volcanic field, eastern-central Europe, provides a rare example of mingled rhyolite. It consists of two distinct pumice populations (‘A’- and ‘B’-type) that can be recognized only by detailed geochemical work. The pumice and the host ignimbrite have a similar mineral assemblage involving quartz, plagioclase, biotite and sporadic Kfeldspar. Zircon, allanite, apatite and ilmenite occur as accessory minerals. The distinct pumice types are recognized by their different trace element compositions and the different CaO contents of their groundmass glasses. Plagioclase has an overlapping composition; however, biotite shows bimodal composition. Based on trace element and major element modeling, a derivation of ‘A’-type rhyolite magma from the ‘B’-type magma by fractional crystallization is excluded. Thus, the two pumice types represent two isolated rhyolite magma batches, possibly residing in the same crystal mush. Coeval remobilization of the felsic magmas might be initiated by intrusion of hot basaltic magma into the silicic magma reservoir The rapid ascent of the foaming rhyolite magmas enabled only a short-lived interaction and thus, a syn-eruptive mingling between the two magma batches.

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Székelyudvarhely határában (Bronze Age populations and Visigoths in the border of Székelyudvarhely) Kiállítás- és szakkatalógus. Székelyudvarhely . I. Kovács

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High concentration of naturally-occurring arsenic in groundwater poses a significant risk to human health if this water is a drinking water resource. Chronic arsenic ingestion has been linked mainly to skin cancer, and a wide variety of non-cancer health impacts. Research conducted in Hungary shows that there is an excessive risk of arsenic-related diseases in populations consuming water that exceeds the 10 microgram/liter limit value. It is therefore important to understand the significance of reduction of arsenic concentration in drinking water and the size of the exposed population.

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Recently, due to population increase in urban areas, underground excavations increasingly influenced the development of cities, parallel with traffic organization. One of the best examples is Eger in North Hungary: several kilometer-long wine-cellars were dug over the centuries beneath the city, which influences further construction; sometimes they present a danger due to the increased weight of surface vehicles as well. Therefore, nowadays the prediction of the stability of these cellars is a question of utmost importance here. The goal of this paper is to statistically analyze the results of strength investigations of the excavated rocks, in order to predict their strength (both compressive and tensile) and Young's modulus. The results of 19 sample blocks are statistically analyzed here in different petrophysical states (air-dry, semi-saturated and fully saturated). The relationships between the different petrophysical constants are also determined and analyzed in this paper. On the basis of these correlations prediction of rock strength has become easier and faster.

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Abstract

A single tooth from the locality of Üröm-hegy (Hungary) was designated as the holotype specimen of “Archidiskodon meridionalis ürömensis” by Vörös (1979). The observed morphology of the tooth, with a minimum of 15 molar plates (most likely 17) led to the conclusion that this specimen belongs to Mammuthus trogontherii rather than a subspecies of M. meridionalis. On the basis of rodent biostratigraphy a date in the region of MIS 19-17 seems likely (i.e. c. 0.8 Ma — c. 0.7 Ma). Taking into account the meridionalis-like enamel thickness (3.1 to 3.4 mm, mean 3.2 mm) as well as the intermediate or slightly advanced relative crown height (1.65) and lamellar frequency (6), the specimen shows mosaic morphology, which fits well in the framework of the contemporaneous European mammoth-bearing localities (e.g. Voigtstedt). Taking all the evidence together it seems that this molar is not only a misinterpreted specimen, but a representative of a very important period of mammoth evolution in Eurasia, when M. meridionalis and M. trogontherii occurred together in Europe and when the genetic mixing between the adjacent populations resulted in a hybrid zone, which was responsible for mosaic or intermediate individuals, such as the holotype of “Archidiskodon meridionalis ürömensis”.

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J. Warburton 2005 Grain-shape analysis — a new method for determining representative particle shapes for populations of natural grains Journal of Sedimentary Research

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populations of single-domaingrains Geophysical Journal International 129 209 211 . M.E. Evans

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the global urban population had increased from 746 million in 1950 to 3.9 billion in 2014. This means that the urbanization process has experienced an acceleration process like never before, with interest in the study of greenness within cities

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S. Farcas A.M. Robertsson 2007 The influence of refugial population on Late Glacial and early Holocene vegetational changes in Romania

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of insect populations. -- Chapman and Hall, London, 734 p. Ecological methods with particular reference to the study of insect populations 734

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