Physical (mechanical) modeling of continental collision is performed with a 4-layered mantle model. Compositionally distinct layers of hydrocarbons are used to model a lithosphere which consists of two crustal layers (the upper one quasi-brittle, the lower one plastic) and a plastic mantle layer. The lower crustal layer, the ''crustal asthenosphere'', has a low yield limit. A low-viscosity liquid (water) represents the asthenosphere under the lithosphere. Lateral compression of the model plate by a piston is the driving mechanism of collision. Similarity criteria are satisfied in the modeling. The collisional process was investigated with various boundary conditions and values of the model parameters. The yield limit and the thickness of the ''crustal asthenosphere'' were varied, as well as the action of the piston on the plate: the force was applied either throughout the plate section, or on its mantle layer only (in the latter case, this layer slipped relative to the upper crust). Hence different results were obtained. A more realistic pattern seems to occur when the yield limit of the crustal asthenosphere is not too small and free sliding of the crustal layers over the mantle lithosphere is not possible. The upper crustal layer then experiences failure in the collision zone and thrusting develops there. Intensive thickening of the lower crust was observed, the mantle layer being subducted like oceanic lithosphere in a subduction zone.
