Origin of calcite-cemented Holocene slope breccias from the Długa Valley (the Western Tatra Mountains

New locality of slope breccias was found in the Western Tatra Mts. It occures in the Długa Valley on a steep slope of ravine beneath the belt of Jurassic radiolarite cliffs. The brecccia consists of angular clasts of radiolarite bound with calcite cements. Void spaces between the clasts contain shells of Holocene snails. The cements are built of columnar crystals composed of acicular subcrystals and of skeletal crystals. The crystals grew rapidly from supersaturated solution due to CO2 degassing. Cementation occurred in vadose conditions in the Atlantcic Phase soon after the scree formation.