Erosion of Coastal Slope in the Zelenka locality, Northern Black Sea Coast of Bulgaria

Abstract

The study covers a coastal slope along the northern Bulgarian Black Sea coast near Cape Kaliakra, Zelenka locality. The slope is composed of Miocene (Sarmatian), unconsolidated aragonite sediments with limestone interbeds (Topola Formation) and a steep limestone rock ridge (Karvuna Formation). Water flows along the surface of the slope, attached to the karstified and cracked limestones of the two formations. An assessment was made of the material eroded from the slope, composed of aragonite sediments of the Topola Formation, for the period from September 2018 to October 2022. The quantities of this material were measured and laboratory tests of the aragonite sediments were carried out. Their classification characteristics have been determined - grain size composition and plasticity index. Geotechnical studies and mapping of the coastal slope showed that erosion processes in the studied area represent a real geological hazard and can affect the stability of the slope, as well as the integrity of the road.