Authors:Mária Földvári, Zsolt Berner, and Doris Stüben
Thermoanalytical (TA) analysis is not at all a frequently used method for studying travertine. Therefore the application of two TA techniques is presented for characterization of the Buda-Vár-hegy (Castle Hill), Budakalász and Szomód-Les-hegy Quaternary travertine occurrences in this paper. TA data give comparable results with those of oxygen and carbon stable isotope compositions and offer a new way to estimate the temperature of carbonate precipitation.
Cavity filling natrolites in basalts from several localities of Balaton Highland were investigated by different methods. The
measurements of different thermal parameters (corrected decomposition temperature and activation energy) were first applied
for natrolite. Energy dispersive spectroscopy (EDS) was used for the observation of chemical composition. Few of the minerals
are regular, ordered natrolite, the majority proved to be so called ‘tetranatrolite’. According to our observations both natrolite
and ‘tetranatrolite’ may appear in the same locality and chemical inhomogenity can be demonstrated within a single natrolite
Authors:Géza Szendrei, Péter Kovács-Pálffy, Mária Földvári, and Kamilla Gál-Sólymos
There is little data on the mineralogy of carbonate pedofeatures in the calcareous soils in Hungary which belong to the European prairie ecodivision. The aim of the present study is to enrich these data.
The mineralogical composition of the carbonate pedofeatures from characteristic profiles of the calcareous soils in Hungary was studied by X-ray diffractometry, thermal analysis, SEM combined with microanalysis, and stable isotope determination.
Regarding carbonate minerals only aragonite, calcite (+ magnesian calcite) and dolomite (+proto-dolomite) were identified in carbonate grains, skeletons and pedofeatures.
The values relating, respectively, to stable isotope compositions (C13, O18) of carbonates in chernozems and in salt-affected soils were in the same range as those for recent soils (latter data reported earlier). There were no considerable differences between the values for the carbonate nodules and tubules from the same horizons, nor were there significant variations between the values of the same pedofeatures from different horizons (BC-C) of the same profile. Thus it can be assumed that there were no considerable changes in conditions of formation.
Tendencies were recognized in the changes of (i) carbonate mineral associations, (ii) the MgCO3 content of calcites, (iii) the corrected decomposition temperatures, and (iv) the activation energies of carbonate thermal decompositions among the various substance-regimes of soils.
Differences were found in substance-regimes types of soils rather than in soil types.