Postsedymentacyjne ruchy wznoszące w rowie Lubstowa (środkowa Polska)

Abstract

Postsedimentary tectonic uplift in the Lubstów Graben (Central Poland).A b s t r a c t. The Lubstów Graben is an exception in the Konin–Turek territory, where the 2nd Lusatian Lignite Seam is present. Its continuous thickness amounts to 86.2 m and additionally it is characterized by a relatively high bhypsometric position. Therefore, the deepest part of the graben had to be affected by negative movements during peat sedimentation and positive ones after the peat bog burial. Using the author's method the peat:lignite thickness ratio is approximately 2.5:1 for the 2nd Lusatian Lignite Seam in the study area. Taking into account the compaction process of peat, its thickness and hypsometry of the lignite base the subsidence as well as uplift can be estimated, respectively. Thus, the amount of subsidence during this peat bog development exceeded more than 200 m. On the other hand, the deepest part of the graben was uplifted at least 100 m after sedimentation of the 2nd Lusatian Lignite Seam in the Lubstów Graben.