Ore mountains - region and history: Difference between revisions

The landscape of North-West Bohemia, with its Ore Mountains, [[wikipedia:en:Sokolov (Sokolov District)|Sokolov]] and North Bohemian coal basins, Central Bohemian Uplands and Egerland, is the result of millions of years of orogenetic processes. The Ore Mountains' crystalline complex was formed during the Hercynian orogeny at the turn of the early Palaeozoic, when older rocks of various ages and origins were affected by metamorphic processes. They were, roughly speaking, sediments saturated with deep magmatic rocks, and deep magmatic rocks themselves. Depending on the nature of the original rocks and the intensity of the metamorphic processes, they were turned into orthogneisses, paragneisses, crystalline slates, crystalline limestones, schists, and phyllites. As part of the Bohemian Massif, the Ore Mountains crystalline complex was part of the Hercynian European mountain system. The massif repeatedly sank and was lifted again in the Mesozoic. The associated erosion and accumulation processes fashioned it into a levelled peneplain by the end of the Mesozoic; its sheet was broken at the edges by the Saxon orogeny in the early Tertiary. The elevated plain of the Ore Mountains and the rift valley below it were formed at the northwestern breach of the Bohemian Massif; it was filled with lake sediments, containing brown coal seams in their older strata, in the course of the Tertiary. The deposition of massive layers of dead organic matter from the tropical vegetation of that era is probably linked to the repeated disastrous effects of volcanoes in the emerging Central Bohemian Uplands and Doupov Mountains. The landscape was then completed by the alteration of colder and warmer periods, the effects of water, vegetation, and the evolution of plant and animal species since the beginning of the Quaternary. The contribution of human activity to the landscape formation can only be recognized in the last millennium.<ref name = Riha>Říha,M., Stoklasa, J., Lafarová, M., Dejmal, I., Marek, J., Pakosta, P., Beránek, K. Environmental mining limits in North Bohemian Lignite Region. Společnost pro krajinu, Praha 2005. Translation: Petr Kurfurst. Updated for the ISPoS summer school in September, 2011</ref>