Gravitational sliding of the carbonate megablocks in the Vipava Valley, SW Slovenia

Abstract

The area of Lokavec in the Vipava Valley, SW Slovenia, consists of Mesozoic carbonates thrust over Paleogene siliciclastic flysch. Overthrusting and tectonic damage of carbonates accelerated their mechanical disintegration. As a result, accumulations of slope gravel and large carbonate gravitational blocks are deposited on the slopes. Based on previous research, basic geological mapping and analysis of the DEM, ten carbonate blocks were identified. The aim of our research was to map lithology, measure and analyse the dip of carbonate strata and to determine transport mechanisms for individual blocks. The displacement of blocks from the source area ranged from 80 m to 1950 m. With the displacement of gravitational blocks, changes in dip direction and dip angle were also observed. The differences between the strata dip of carbonate source area and gravitational megablocks are from 4° to 59°.