This work is a study of physical properties of rocks collected from the Swiss Alps. The major interest is that the structures where the rocks come from have been prospected by seismic reflection method (in the frame of PNF20 program).

The first part of the thesis describes the experimental methodology and discusses the physical parameters that may affect seismic velocity estimates. The errors associated with the data are computed and the bounds of the results emphasized to give the potential and limitations of rock property estimates. The wide variety of alpine rocks are classified according to their densities, velocties and velocity anisotropies. The velocity anisotropy behavior is described in terms of linear, planar and triaxial behavior. A new empirical formulation that describes the manner in which the velocity changes with increasing confining pressure is proposed.

The second part of the thesis demonstrates the utility of rock property information in interpretaing seismic reflection data. The reflectivity of the profiles is studied through the determination of the acoustic impedances. The seismic profiles East and West (W1-W4) have been studied, sometimes from a global point of vue or from a more detailed one.

These rock properties of the alpine crust are not only a reliable data base but by bringing new constrains to seismic interpretation they contribute to the knowledge of the crustal structure under the Alps.