Modelling complex 3D depositional geometry using UAV based photogrammetry

During the last decade the use of 3D digital outcrop models in the geoscience community has widely spread out renewing the way geologists analyze outcrops. We present two large scale field case studies where 3D digital outcrops were used as additional tools to improve field geologist work, both on site and back home. UAV photogrammetry was chosen as a cost effective method to quickly scan at a good resolution several kilometres of outcrops with high exposed vertical cliffs. The first study is dedicated to the Permian Cutler formation. These outcrops present fluvial channels interbedded with aeolian and shallow marine deposits, and are viewed as potential analogues of North Sea Rotliegend reservoirs. The 3D digital outcrop model was interpreted back home, based on field work. A geomodelling tool was used to construct 3D horizon surfaces and layers and map in 3D channelized fluvial deposits. The second study is dedicated to Corinth Gulf outcrops (Greece), showing recent deep marine clastic carbonates deposits at the base of giant Gilbert deltas in an active tectonic setting. Ten stratigraphic surfaces were calibrated on the field logs, interpreted, and correlated in 3D across the whole digital outcrop model.