Extensional collapse related to compressional uplift in the alpine chain off northern Tunisia (Central Mediterranean)

Geophysical and geological marine data recently collected allow to outline the structure of the basement-involved fold-thrust belt, developed during the Late Cenozoic between Sardinia and Tunisia, along the Africa-Europe plate boundary. By integrating these with inland data, it is possible to document, step by step, the progression of crustal thickening from north to south, and the collapse of the first uplifted northern units, while collision was still going on. The geodynamic setting suggests that coupled extensional collapse and fold-thrust propagation were driven by island arc drifting above a southward-retreating subduction zone. © 1994.