The Alejico Carboniferous Forest: a 3D-Terrestrial and UAV-Assisted Photogrammetric Model for Geologic Heritage Preservation

Abstract

The Alejico coalbeds represent a well-preserved Carboniferous fossils site characterised by the presence of tree trunks in life position and parallel to bedding. The area, located near the Picos de Europa National Park (Spain), between the Leon and Asturias provinces, lacks of any kind of preservation directives, thus being influenced by weathering, erosion and anthropogenic destruction. We present a photogrammetric study carried out through terrestrial and UAV-assisted technology in order to collect digital 3D information for fossil analysis and future preservation. A general overview of the steep wall of the outcrop and a detailed section of the fossil forest have been implemented into a reliable and accurate point cloud. Qualitative and quantitative information was obtained from a georeferenced high-resolution digital 3D model used for the characterisation of the different outcrop features, which aimed specially at the fossil conservation. The results provide useful information on the nature and paleoenvironment of carboniferous forests with important implication for scientific and educational interests. These technologies provide new possibilities for better preservation and diffusion of geologic heritage locations prone to be damaged, and enables public awareness for the protection of fossil sites with high scientific and cultural value.