Publication details
Vltavínové hrance
| Title in English | Facetted Moldavites |
|---|---|
| Authors | |
| Year of publication | 2013 |
| Type | Article in Periodical |
| Magazine / Source | Geologické výzkumy na Moravě a ve Slezsku |
| MU Faculty or unit | |
| Citation | |
| Field | Geology and mineralogy |
| Keywords | South Bohemia; Tertiary cover of Moldanubian; Holocene; Moldavites; Fluvio-Lacustral sediments; Eolic abrasion; Faceted pebbles |
| Description | On several locations in South Bohemia are fluvio-lacustral sediments of Tertiary (Pliocene, lower Ruman). These sediments are probably formed by activities of paleorivers Blanice and Radomilický brook. Sediments are many times redeposited on gravel terrace. In recent relics of these sediments were found page facetted boulders of quarz and other solid material. Moldavites from strown field of Radomilice area are tied on these positions of gravel sands. Gravel sediments with moldavites were several times redeposited and therefore there are round stones with distinct abrasion. Frequent findings of facetted boulders caused the study of moldavites from these locations. Locations of facetted moldavites occurences has been confirmed – Březí, Dříteň, Dubenec and Zbudov. On the sites with similar conditions can be expected its occurrence. Also we can assume that Tertiary sediments formed large position at elevated plains. These 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 Holocene, when were dry, cold and windy conditions without vegetation. Facetted moldavites are uniquely complicated evidence of the origin and evolution of this interesting geologic phenomenon and their bearing sediments. |