Rhyolite Badland at Kazár

Abstract

In North-Hungary, east of the Danube the hilly regions and middle mountains mostly consist of Oligocene–Miocene geological formations. Among them the early Ottnangian rhyolite tuff (Gyulakeszi Rhyolite Tuff Formation) is very typical. The tuffs are mainly ignimbrites originated from episodes of intensive volcanic eruptions repeated two to four times. The formation consist of pumice tuff (89 %), dust tuff (5 %) and coarse lithoclastic tuff (6 %, mainly pumice fragments), which determines the morphology of the outcrops. The rhyolite tuffs outcrop in greyish white cliffs and whitish barren patches. The barren rhyolite tuff surfaces are optimal for erosional processes, especially for gully development. Weathering, disintegration and sheet wash erosion intensively shape the landscape. Erosion is also influenced by granular structure and biogenic effects. Close to the village Kazar the erosional forms of the most extensive outcrop present a spectacular badland-like terrain. On other outcrops the formation and exfoliation of thin crusts, piping, the emergence of candle-like columns and earth pyramides produce a remarkable assemblage of micro and macroforms.