Authors:P. Rózsa, S. Szakáll, Éva Balázs, and A. Bartha
Rhyolite-rhyodacite tuff samples were analysed by X-ray powder diffraction, ICP-OES and thermogravimetric (TG) methods to
determine mineral and major element composition as well as different types of bound water, respectively. Similarly to CIA
values, some TG parameters (H2O[I] — water released up to ca. 200–220°C; H2O[III] — water loss above 500–550°C and H2O[I+III]) show positive correlation to the amount of secondary minerals. Moreover, these parameters are in close positive
correlation to CIA values. Our results suggest that TG determination of different types of bound water may serve as a useful
tool for estimation and characterisation of alteration degree of rocks.
Authors:P. Rózsa, Z. Elekes, Gy. Szöőr, A. Simon, J. Simulák, I. Uzonyi, and Á. Kiss
The aim of the current paper is to map minerals mainly of Carpathian obsidian glasses by nuclear microprobe based on the particle induced X-ray emission (PIXE) providing analytical data on them for the first time. Some samples from Armenia, Greece are also involved to make a comparison with the Carpathian specimens. The following minerals are identified and analyzed: pyrrhotite, chalcopyrite, pyrite, zircon, pyroxene, biotite, plagioclase feldspar, and anhydrite. On the basis of rock-forming silicate minerals, some petrologic processes are outlined. With the identification of accessory minerals (anhydrite, pyrrhotite, chalcopyrite, pyrite), some geological conclusions are also drawn.