Tarn (river) a mean flow of approximately . The Millau Viaduct spans the valley of the Tarn near Millau, and is now one of the area's most popular attractions. The tributaries of the Tarn include: The Tarn separates the Narbonne and Aquitaine basins. The Tarn passes through the following departments and towns: The Millau Viaduct, the tallest bridge in the world, carrying the A75 autoroute across the Tarn Gorge near Millau, opened in December 2004. The Tarn is famous for its brutal floodings, which are the most dangerous in Europe along with the Danube. The flooding of March 1930 saw the Tarn
Geology of the Massif Central the crater structure is almost completely eroded away, yet some suevites, several impact breccias, planar deformation features (PDFs), shatter cones and many local thrusts in the basement still document this event. Structurally the Massif Central consists of stacked metamorphic basement nappes that have been overthrust onto their southern foreland (Aquitania). The following structural units can be discerned (from structurally higher to structurally lower): Geodynamically the Massif Central can be subdivided into six major deformational phases, according to Faure et al. (2008): It seems now well established that at the end of the Neoproterozoic the Massif Central (i.e. the microcontinent Ligeria)