Geological influence on the formation of Samar natural bridge and collapse valley of Ravna River from the NE Kučaj Mountains (Carpatho-Balkanides, eastern Serbia)

Abstract

The paper deals with the description of Samar natural bridge and collapse valley of Ravna River in eastern Serbia aiming to suggest an interpretation of their origin and development, in relationship with lithological and tectonic conditions, karst processes, and petrological analyses. In this study we present the geological setting, detailed morphology and hypothesis on the genesis of these karst landforms. The relationship between surface karst development and the geology is considerably acknowledged. The major contribution of the paper is to propose a framework for considering how recrystallization of limestone can affect the weathering potential of karst landforms and to introduce a term collapse valley. Finally, this study shows that the weathering potencial of the Samar natural bridge is decreased concerning the diagenetic changes these limestones underwent.