High-resolution digital outcrop models of fossil-rifted margins: 3D imaging of extensional detachment systems

Few localities are as important as the outcrops of the remnants of the Alpine Tethys margins exposed in European Alps in the development of new concepts on the temporospatial evolution of magma-poor rifted margins. The Tasna and Err detachment systems are among the best exposed and preserved structures related to extreme crustal thinning and mantle exhumation world-wide. These detachment systems shaped the most distal parts of the fossil Alpine Tethys magma-poor rifted margins and are key analogues of present-day deep-water examples that can only be imaged through geophysical methods. We present the first digitalisation and integration of the Err and Tasna detachment systems using structure-from-motion photogrammetry. The resulting high-resolution models offer details down to 7 cm and cover multi-kilometre cross-sections from various angles. Comparing these 3D digital outcrop models with high-resolution seismic images from the Galicia distal margin allows us to constrain interpretations of the structures and processes that control the formation of distal passive margins. All data are openly available under FAIR (Findable, Accessible, Interoperable, and Reusable) conditions to the geoscientific community, and we hope this contribution will be the first of many that contribute to the ongoing digitalisation of key outcrops of the fossil Alpine Tethys margins in the European Alps.