The RFM (relative fraction magnitude) program is proposed as an aid in the estimation of depth to ore-mineral concentration. This estimate is based on the determination of the relative position of the sampled surface plane within the zonational framework of a hydrothermal sulfide mineralization. The program requires analytical data on two sample fractions collected at the same localities. The first of these must selectively concentrate iron and manganese oxides (exclusive of magnetite) and, the other, the sulfides and their oxidized zone derivatives.