Evolutionary model for Alpine Corsica: mechanism for ophiolite emplacementand exhumation of high-pressure rocks

A tectonic model of Alpine Corsica is proposed based on geological studies. Its evolution starts after the Jurassic with intraoceanic subduction, foll owed by mid-Cretaceous subduction of the European continental margin under the oceanic segment of the Adriatic plate. After subduction of the continen tal crust to a depth of approximate to 150 km, slices of crustal material a re buoyantly uplifted together with high-pressure oceanic rocks (ophiolites and 'schistes lustres'). High pressure-low temperature continental gneiss units overthrust the outer segments of the European crust, while producing a normal sense motion along the upper surface of the rising crustal body. D uring the Eocene, the closure of the remnant Ligurian oceanic basin separat ing the proto Corsican belt and Adria, resulted in a second orogenic phase with the emplacement of unmetamorphosed ophiolitic nappes which overthrust the previously exhumed and eroded HP belt, This Corsican model suggests an original evolutionary path for orogenic belts when continental collision is preceded by intraoceanic subduction.