标题：Geological background of the occurrences of Carpathian volcanic glass, mainly obsidian, in Eastern Slovakia = A vulkáni üvegek, főként az obszidián földtani viszonyai Kelet-Szlovákiában
摘要：Primary natural occurrences of volcanic glass in the region of Eastern Slovakia are associated with other
products of silicic (rhyolite, rhyodacite) volcanism. This Upper Badenian to Lower Pannonian volcanism was a
part of the bimodal andesite/rhyolite volcanic activity. Products of the silicic volcanism occur as tuffs and
pumice tuffs, reworked epiclastic volcanic rocks, rare intrusions and dominantly as extrusive domes that
sometimes pass into short and thick lava flows. The volcanic glass associates with intrusive and extrusive forms
of silicic volcanism and occurs in massive as well as brecciated forms (e.g. in the type locality of Merník), or as
perlite (Brezina, Byšta) and perlite with obsidian (Malá Bara, Viničky). Rarely the volcanic glass can occur in
explosive forms of silicic volcanism (obsidian – Hermanovce, Veľká Bara). Fragments of perlite with obsidian
and rare obsidian, occurring alone, are a part of reworked rhyolite/rhyodacite tuffs, epiclastic volcanic
sandstones and gravels, as well as epiclastic volcanic breccias, all occurring near the municipality of Streda nad
Bodrogom. In Quaternary deposits, obsidian occurs around the Cejkov and Brehov villages.
关键词：EASTERN SLOVAKIA; SOURCES OF OBSIDIAN; FACIES POSITION; EVOLUTION OF OBSIDIAN SURFACE
