VLTAVÍNOVÉ HRANCE

František Knížek, Martin Knížek, Jan Krška, Jakub Lukášek

Abstrakt

Fluvio-lacustral sediments of Tertiary (Pliocene, lower Rumanian) on several locations in South Bohemia occur. These sediments are probably formed by activities of paleoriver Blanice and Radomilický brook. Sediments were many times redeposited on gravel terrace. In recent relics of these sediments facetted boulders of quartz and other solid material were found.

Moldavites from strewn field of Radomilice area are tied on these positions of gravel sands. Gravel sediments with moldavites were several times redeposited and therefore there are rounded stones with distinct abrasion. Frequent findings of facetted boulders caused the study of moldavites from these locations. Occurences of facetted moldavites has been confi rmed – Březí, Dříteň, Dubenec and Zbudov. Their occurence can be expected at the sites with similar conditions. Also we can assume that Tertiary sediments formed large position at elevated plains. Such uncovered plains were exposed during the period with low vegetation to intense eolic activity. Ideal conditions for the formation of facetted boulders and moldavites were in the Pleistocene, when dry, cold and windy conditions prevailed along with lack of vegetation cover. Facetted moldavites are uniquely complicated evidence of the origin and evolution of this interesting geologic phenomenon and their bearing sediments.

Bibliografická citace

Knížek, F., Knížek, M., Krška, J., & Lukášek, J. (2013). VLTAVÍNOVÉ HRANCE. Geologické výzkumy na Moravě a ve Slezsku, 20(1-2). Získáno z https://journals.muni.cz/gvms/article/view/1540

Klíčová slova

South Bohemia, Tertiary cover of Moldanubian, Pleistocene, Moldavites, Fluvio-Lacustral sediments, Eolic abrasion, faceted pebbles

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Reference

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