Reconstructing hydrological variability from testate amoebae analysis in Carpathian peatlands

Peatlands offer the potential for high resolution records of water balance over Holocene timescales, yet this potential is under-exploited in many areas of the world. Within Europe, peatlands are mostly confined to areas north of 55° N, but several areas of southern and eastern Europe contain small peatlands which may be suitable for palaeoclimatic reconstruction. In this paper we test the potential of peatlands in the Carpathian region for deriving quantified estimates of water table changes using testate amoebae analysis. A training set for palaeohydrological reconstruction from testate amoebae assemblages was obtained by collecting surface samples from 13 peatlands, including 9 from Hungary and 4 from Transylvania (Romania). Using a simple measure of mean annual water tables estimated from staining of PVC tape, we found that some peatlands were heavily influenced by runoff and groundwater, and were therefore not suitable as modern analogues of ombrotrophic climatically sensitive sites. The relationship between the testate amoebae assemblages in the modern samples and the environmental variables was explored using CCA. The CCA biplot showed that the most important variables are depth to water table and moisture content, confirming that hydrology is a key control on taxon distribution. pH was a secondary gradient. A transfer function for % moisture and depth to water table was established and applied to fossil assemblages from a sequence from Fenyves-tető, Transylvania, Romania. The reconstructed water table shows a number of variations which have parallels with other palaeoclimatic records from Europe and the North Atlantic prominent phases of higher water tables are associated with the periods 8000–8300 cal BP, 3000–2500 cal BP and after 600 cal BP. We suggest that these were periods of particular intensification of westerly airflow which affected eastern Europe as well as western and central Europe.     

Monopole abundance from first-order GUT phase transition of the early Universe

Monopole annihilation and pair creation are investigated in a first order GUT symmetry breaking phase transition without inflation. It is found that even with complete initial monopole suppression, some monopoles are inevitably produced during the transition. According to this, some constraints are obtained for initial and equilibrium monopole densities in order to be compatible with the present observational limits even without inflation.     

Alkaline lamprophyre and related dyke rocks in NE Transdanubia,Hungary: The Alcsutdoboz-2 (AD-2) borehole

Summary The Alcsutdoboz-2 (AD-2) core contains 12 magmatic dykes which belong to the Late Cretaceous lamprophyric-carbonatitic association of NE Transdanubia, Hungary. Petrographically, 11 dykes can be considered alkaline lamprophyre (mainly monchiquite), and the remainder might be called carbonatite. The lamprophyre dykes are similar to both alkaline lamprophyres and ultramafic lamprophyres in major element composition, whereas the carbonatite dyke has some features that are similar to carbonatites but others that are dissimilar. Nevertheless, both of the two types of AD-2 dykes possess higher LILE content than the ultramafc lamprophyres and kimberlites, but strongly differ from average carbonatite. Based on the REE pattern, crystal fractionation (mainly of olivine) and separation of a carbonate phase from the parental lamprophyric magma are proposed for genesis of the carbonatite dyke. These characteristics and the compositional zoning of clinopyroxene and mica suggest a complex crystallization history for these dykes. The likeliest origin for the parental lamprophyric melt is through a very small degree of partial melting of metasomatized mantle.

---

Alkalische Lamprophyre und assoziierte Ganggesteine in Nordost-Transdanubien, Ungarn: die Bohrung Alcsutdoboz-2 (AD-2)

Zusammenfassung Der Kern der Bohrung Alcsutdoboz-2 (AD-2) enthält zwölf magmatische Gänge, die zu der jung-kretazischen Lamprophyr-Karbonatit-Assoziation des nordöstlichen Transdanubiens in Ungarn gehören. Petrographisch gesehen gehören elf Gänge zu den alkalischen Lamprophyren (hauptsächlich Monchiquit), und der Rest kann als Karbonatit bezeichnet werden. Die Lamprophyrgänge sind in ihrer Hauptelementzusammensetzung sowohl alkalischen Lamprophyren wie ultramafschen Lamprophyren ähnlich. Der Karbonatitgang hingegen zeigt Parameter, die denen von Karbonatiten teilweise, aber nicht durchwegs, ähnlich sind. Beide Typen der AD-2-Gänge zeigen höhere LILE-Gehalte als ultramafische Lamprophre und Kimberlite, unterscheiden sich aber deutlich vom durchschnittlichen Karbonatit. Auf der Basis der Seltenen ErdVerteilung, werden Kristallfraktionierung (hauptsächlich von Olivin) und Abtrennung einer Karbonatphase von lamprophyrischen Magma als Vorgänge gesehen, die für die Entstehung der Karbonatit-Gänge relevant sind. Diese Aspekte und die Zonierung der Zusammensetzungen von Klinopyroxen und Glimmer weisen auf eine komplexe Kristallisationsgeschichte dieser Gänge hin. Sehr wahrscheinlich ist die lamprophyrische Ausgangsschmelze durch eine geringfügige teilweise Aufschmelzung von metasomatisiertem Mantel entstanden.

     

EM Cygni: A study of its eclipse timings

EM Cygni is a Z Cam‐subtype eclipsing dwarf nova. Its orbital period variations were reported in the past but the results were in conflict to each other while other studies allowed the possibility of no period variation. In this study we report accurate new times of minima of this eclipsing binary and update itsO –C diagram.We also estimate the mass transfer rate in EM Cygni system and conclude that the mass transfer is far from the critical value. The mass transfer rate determined from the eclipse timings is in agreement with the spectroscopically determined value. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Optical flares from the faint mid‐dM star 2MASS J00453912+4140395

We present B and V light curves of a large stellar flare obtained with the Wide Field Camera at the Isaac Newton 2.5‐m telescope (La Palma). The source object is a faint (m_V = 21.38) foreground star in the field of the Andromeda galaxy, with its most probable spectral type being dM4. We provide an estimate of the total flare energy in the optical range and find it to be of the order of 1035 erg. The cooling phase of the large flare shows three additional weak flare‐like events, which we interpret as results of a triggering mechanism also observed on the Sun during large coronal mass ejections. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Monte‐Carlo simulation of a possible correlation between the estimated luminosity distances and internal extinctions of type Ia supernovae

This paper describes a Monte Carlo simulation of type Ia supernova data. It was shown earlier that the data of SNe Ia might contain a possible correlation between the estimated luminosity distances and internal extinctions. This correlation was shown by different statistical investigations of the data. In order to remove observational biases (for example the effect of the detection limit of the observing instrument) and to test the reality of the effect found earlier we developed a simple routine which simulates extinction values, redshifts and absolute magnitudes for Ia supernovae. We pointed out that the correlation found earlier in the real data between the internal extinction and luminosity distance does not occur in the simulated sample. Furthermore, it became obvious that the detection limit of the observing devices used in supernova projects does not affect the far end of the redshift‐luminosity distance relationship of Ia supernovae. This result strengthens the earlier conclusions of the authors that SN Ia supernovae alone do not support the existence of dark energy. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Computer estimation of intensities: The 1985 Berhida,Hungary, earthquake

In this paper a computerized method for the intensity estimation from macroseismic observations is presented. The successive steps of the MSK intensity scale (2° to 10°) receives weights according to the observations marked on the earthquake questionnaires. These weights are summed for the individual scale steps. The distribution of these summed weights and their relation to an experimentally chosen function of the criterion make it possible to estimate the appropriate intensity value and its reliability. By computer evaluation of earthquake reports an objective comparison of estimated intensities given by different seismologists can be made, provided that uniform earthquake questionnaires are used. The application of this method will result in more homogeneous intensity data.     

Changes in Hungary's agrarian sector with special reference to the northern hill region

The Hungarian agriculture and food industry has changed greatly since 1989 and this sector is now in crisis. This essay will present an overview of the most important economic and social problems which are partly the heritage of the socialist system, but which also stem from the change in the political system. It will also deal with the specific problems of the transition in the northern hill region of Nógrad where the physical conditions for agriculture are relatively unfavourable. In 1970s and 1980s state farms and cooperatives tried to compensate for the low demand for labour in agriculture by setting up subsidiary enterprises, which in many cases were the only source of local jobs. Many other people in the rural areas commuted to work in factories in the towns as industry and construction became the largest sector in the county's economy (41.3 percent in 1990 compared with 19.8 in agriculture). However, many of the former commuters are now unemployed and the cooperatives have withdrawn from subsidiary enterprises. So while an unstable situation has developed in Hungarian agriculture generally, through changes in structure and ownership, the problems faced by the less-developed agrarian regions of northern Hungary have been accentuated. Further research is needed to explore the real nature of the crisis in order to make provision for remedial action that best meets the local situation.