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Třetihorní subtropy

The Erika Sand Pit

The Erika Sand Pit is known internationally as a locality of Eocene flora. The fossil plant community of the Staré Sedlo formation bears traces of the so-called primeval evergreen forests of the subtropical zone. The characteristic wood species are Daphnogene (Daphnogene cinnamomea), the predecessor of oak trees (Eotrigonobalanus furcinervis), Laurel (Laurus), Marica (Myrica) or fan palms (Sabal). The sand quarry provides an ideal location for observation of various stratification types, bedding and rock structure, which indicate the mechanism and the environment present during the formation of the strata. It is the most exposed section of the Staré Sedlo formation, which is the oldest sedimentary unit in the Sokolov Basin. It was formed in the early Tertiary Period by fluvial streams and shallow lakes and therefore contains primarily gravel and sand, which was consolidated in places forming conglomerates and sandstone. The formation in the sand quarry has an overall thickness of over 20 m. The top 12 m above the groundwater level were subjected to extraction. 

An interesting natural environment has developed in the abandoned sand quarry. The succession processes clearly advanced in the older sections, which have been covered with Heather (Calluna vulgaris), Silver Birch (Betula pendula), Scots Pine (Pinus sylvestris) and other species that are adapted to nutrient-poor stands. Elsewhere the succession has not advanced into the higher vegetation phase – looser areas without vegetation alternate with grassy sections, wetlands and water areas. Gradually, vegetation such as bentgrass (Agrostis), rushes (Juncus), bulrush (Typha) or floating pondweed (Potamogeton natans) starts to dominate. The damp and humid environment of these biotypes are appropriate places for the occurrence of amphibians, such as frogs (Rana), the European tree frog (Hyla arborea), the Natterjack Toad (Bufo calamita), the Common Toad (Bufo bufo), the Common Newt (Triturus vulgaris) and the Great Crested Newt (Triturus cristatus). From May until August, a colony of Sand Martins (Riparia riparia) settles in the sand quarry, boring long nest tunnels into the quarry walls. 

GPS position

N 50° 13.018', E 12° 36.163'