High-resolution 3-D mapping using terrestrial laser scanning as a tool for geomorphological and speleogenetical studies in caves: An example from the Lessini mountains (North Italy)

Abstract

Terrestrial laser scanning (TLS) is increasingly used in geomorphology for the study of medium- to small scale landforms. A light weight, compact and portable TLS device has been used in the Grotta A Cave (Mt. Lessini, N Italy) to make a detailed 3D model of the underground environment. A total of 16 scans were used to survey the about 150 m long cave in < 6 h. The 3D model of the cave walls makes it possible to carry out morphometric measurements on the different cave environments. The TLS data allowed us to calculate cave volumes and distinguish cupola, phreatic conduit and basalt dike volumes. Wall roughness analysis also allowed recognising smaller-scale morphologies such as megascallops, differential corrosion forms and mineral crusts. These observations have enabled us to discern between different karstification processes and speleogenetic phases, highlighting the importance of condensation-corrosion on the cave passage enlargement in a quantitative way.