Morfotektonika Obniżenia Żytawsko-Zgorzeleckiego

Abstract

MORPHOTECTONICS OF THE ŻYTAWA-ZGORZELEC DEPRESSION (SW POLAND) Summary The paper describes the possibility of using two carthometric methods, i.e. analysis of geomorphological and condensed contour line maps to interpret neotectonic activity. These methods have been used in the Żytawa-Zgorzelec Depression. The area is composed of gneisses and granites of the Izera and Lusatian blocks boundary zone. In the northern part of the studied region the Variscan, epimetamorphic complex of Kaczawa Mts. and Zgorzelec (Görlitz) Slade belt occurs. These two older tectono-stratigraphic units are overlapped by the North-Sudetic and North Bohemian Synclinoriums. Another structural rebuild is related to the Laramian orogeny. The Krusne Hory-Ohře tectono-volcanic rift zone began to form in Late Cretaceous. The rift was active during Tertiary times, and an analysis of topographic maps shows that this activity has not yet been completed. It is evidenced indirectly by morpholineaments that form characteristic rhomboidal, orthogonal or en echelon pattern. The morpholineaments are very well visible despite the fact that the area studied has been affected by at least one of the South Polish glaciations (Elsterian I or II) and, probably, the Odranian (Saalian) one. Other indicators of a relatively low tectonic activity are weak earthquakes recorded during the last millenium and the presence of thermal spring in the bottom of the open-pit lignite mine in Turów II.