We present a nonlinear approach for reconstruction of discontinuities in geological environment (Earth's crust, say). The advantage of the proposed method is that it is not limited to a Born approximation (small angles of propagation and weak scatterers). One can expect significantly better images since larger apertures including wide angle reflection arrivals can be incorporated into the imaging operator. In this paper, we treat only compressional body waves; shear and surface waves are considered as noise. ¿ American Geophysical Union 1990