evolution of various volcanic areas in Hungary has been determined by (a) the
original volcanic succession and related, primary landforms and (b) the
subsequent postvolcanic tectonism and erosion. This overview presents some
details of these processes through selected relief types from the Miocene
volcanic mountains of Hungary: the High Börzsöny erosional caldera rim, the
Rocks of Vadálló-kövek, the Dobogókõ Ridge, the Danube Bend area, and
the badlands and fairy chimneys of the southern foreland of the Bükk Mts, by
showing different volcanic relief types, and postvolcanic tectonic,
paleogeographic and erosional history. In the Quaternary, the tectonic
transformation of these and other volcanic areas has been highly variable; in
contrast, erosional processes of the Quaternary, i.e. pedimentation, loess and
other eolian sedimentation, derasion, periglacial relief formation, and channel
erosion, have affected almost all areas in Hungary; hence types and rates of
erosion can be well constrained.
Authors:Zsófia Pálos, István János Kovács, Dávid Karátson, Tamás Biró, Judit Sándorné Kovács, Éva Bertalan, Anikó Besnyi, György Falus, Tamás Fancsik, Martina Tribus, László Előd Aradi, Csaba Szabó and Viktor Wesztergom
The past decade has seen a great number of studies dealing with magmatic water contents and how these could be retrieved by the nominally anhydrous minerals’ (NAMs) trace structural hydroxyl (water) contents. Constraints have been made to magmatic hygrometry with clinopyroxene and plagioclase. Although results suggest that the method is more flexible and reliable than melt inclusion studies, they also indicate that the trace hydroxyl contents could still be overprinted by syn- and post-eruptive processes. Clinopyroxenes can hold more structural hydroxyl than plagioclases. A comprehensive review is presented with the inclusion of all published results so far to compile the available pieces of information. As a case study, micro-FTIR measurements are made of a representative set of plagioclase phenocrysts from the Börzsöny Mts. (Carpathian–Pannonian Region). The samples were selected to represent the progress of the volcanic activity in time and space, considering the petrologic and geochemical evolution of volcanic products in well-defined volcanostratigraphic positions. The syn- and post-eruptive cooling rate seems to have the greatest effect on water retention. This means that the systematic investigation of water in volcanic phenocrysts can contribute to distinguish the slowly and rapidly cooling parts of the volcanostratigraphic units.