The paper represents materials which evidently show small amplitude faults in the gravitational field, poorly seen in a wave field, and appearance of peak of instability among ∆g curves reflecting features of «thin structure» of the gravitational field which can be considered as objects potentially containing oil and gas. The purpose of this paper is an attraction of attention of users of subsoil resources on necessity to carry out precision gravimetric or even better to do gravimagnetic investigations along seismic profiles using combined scheme.