1. Process for extracting a geological horizon and related properties from a seismic representation, in which there is constructed a continuous function S ij,k (t) by interpolation or approximation of the discrete seismic functions of a multidimensional seismic matrix, said function being designated as a “continuous local seismic trace”, comprising the following steps: a). using as optimum (vertical) offset of two adjacent continuous local seismic traces, the value of offset rendering the maximum their correlation function, this optimum offset being not necessarily a whole number multiple of the vertical sampling interval; b). taking as conditional neighborhood a central continuous local seismic trace S ij,k (t), the sub-neighborhood consisting in adjacent traces S pq,k (t) corresponding to optimum offsets h ij,pq,k associated with correlations R ij,pq,k (h ij,pq,k ) greater than a predetermined threshold comprised between 0 and 1; c). constructing a two-dimensional extraction matrix adapted to be filled with extracted points belonging to the same horizon as the one passing through the seed point; d). selecting a seed point P(i,j,t) and determining the point P(i,j,k) of the three-dimensional seismic matrix that is vertically closest; e). estimating the properties associated with the conditional neighborhood and filling the two-dimensional extraction matrix with properties offset by translation of the current variable (t) of the optimum offset value (h ij,pq,k ) corresponding to the vertically nearest point (i,j,k).