Four à Chaux outcrop. (a) Interpreted UAV orthoimage of the rocky shelf and weighted rose diagrams of the digitized faults and fractures. (b) Orthoimage extract showing NNW-SSE and NW-SE fractures both abutting on and crosscutting WNW-ESE fractures with weighted rose diagrams of the digitized fractures. (c) Stereographic projection of structure measured in SU5. (d) and (e) Pictures of the fault mirror of the normal fault hosting ASN201 sample showing barite (underlined in red) and calcite (underlined in green) associated with vertical slickenside. See Table 1 for brittle structure nomenclature.