The geological setting of Matra ore deposit (France): insights from lithostratigraphy and polyphase deformation history

Arsenic sulfide mineralization in Matra mine (southern Alpine Corsica) is hosted by two tectonic units belonging to the Schistes Lustrés Complex. Country rocks include a Jurassic ophiolitic sequence and related sedimentary covers, which were metamorphosed. Geological mapping and thin section analysis were used to understand lithostratigraphy and the tectononic-metamorphic history. The polyphase deformation history includes four phases of ductile deformation during the Late Cretaceous-Early Oligocene Alpine orogeny, with associated high-pressure-low-temperature metamorphism culminating in eclogite facies. The post-Alpine phase includes an N-S extensional fault system that controls the movement of ore fluids.In the Matra area, the Santo Pietro di Tenda (ophiolitic sequence and sedimentary covers) and the Upper Castagniccia (sedimentary covers) Units crop out.They were involved in Alpine subduction registering a polyphase deformation and a peak metamorphism recorded in eclogite facies.The post-Alpine, N-S-trending normal fault of Matra hosts As-sulfide mineralization was exploited in the 1900s.