The Gardnos structure is the remnants of an ancient impact crater, likely 546 Ma old. The structure today comprises a roughly circular area of 5 km diameter where outstanding impact-related rocks are exposed. The main types of these “impactites” are crushed basement rocks (Gardnos breccia) and rocks consisting of clastic impact debris mixed with impact melt and shocked material (suevite). Overlying these impactites are also preserved some sedimentary rocks that were part of the crater infill deposited in the crater depression after impact.
Gardnos breccia
Suevite