The thermal field in a basin after a sudden passive pure shear lithospheric extension and sublithospheric mechanical erosion: the case of the Tuscan Basin (Italy)

A simple new model for sudden lithospheric thinning that considers the crus t to be stretched and the lower layer of the lithosphere to be partially st retched and partially mechanically eroded is proposed. This model allows ca lculation of the thermal field of the lithosphere during the initial warmin g phase and the surface uplift. Application of this model to the Tuscan Basin explains the high regional he at flux density values (> 100 mW m(-2) ), the tectonic subsidence (about 1 km) and the average uplift (> 400 m) observed in this region well.