Publisher © Czech Geological Survey, ISSN: 2336-5757 (online), 0514-8057 (print)
Contribution to volcanology of the Litoměřice area, North Bohemia
Abstract
A new volcanological type of rock was recognized during a recent survey. Tephritic to trachybasaltic ignimbrites were identified on Dlouhý vrch Hill in the northern vicinity of Litoměřice. They alternate with terrestrial lavas and/or lahars of the Děčín Fm. Their crater vents are represented by several smaller bodies. In this area, lower volcanics of the Ústí Fm. are not developed and the ignimbrites overlie the Cretaceous marine sandstones and the Tertiary fluvial redeposited sands with Middle Eocene to Lower Oligocene flora, preserved as quartzites. Silicification was believed to be caused by weathering in a prevolcanic period. This paper shows a possibility of another origin - (thermal) effect of probably hot pyroclastic flows on sands and sandstones, and a possibility of a different lithostratigraphic relationship of the Skalice/Zitenice Quartzite than believed before.
