The Boutenac hills in the northeastern Corbieres region of southern France, are part of the autochthonous foreland of the eastern Corbieres nappe. They are an isolated massif between the Paleozoic formations of the Alaric mountain on the west, and the Jurassic and Cretaceous formations of the Fontfroide chain on the east, entirely surrounded by alluvium. Structurally, they comprise Mesozoic formations on the east thrust over the Eocene on the west, on a fault that is the prolongation of the Saint Chinian frontal fault to the northeast. The Mesozoic formations comprise upper (?) Triassic shale and dolomite, sandy limestone, dolomite, and limestone; Jurassic red sandstones and shales; and upper Cretaceous transgressive clastics. The Eocene is limestone and marl overlain by continental conglomerate and molasse, transgressive on the west upon the Alaric Paleozoics. Folding and thrust and normal faulting are important in the structure.