A quantitative method for target prediction using the wide composition-spectrum dike swarms： A case study of the South Alataw Mountain in Xinjiang

Abstracts：A numerical method is presented for spatial targeting by parametrizing distribution of the wide composition-spectrum dike swarms (WSDS). According to the metallogenic theory on the transmagmatic fluids, the local stress field with a vertical maximum principle stress axis emerges when violent interaction between the magma body and the shielding layer takes place. Consequently the corresponding fissure system differs from the fissure system described in the traditional structural geology of orefield. In accordance with a variety of ascending rates of magma and textural and mechanical properties of the shielding layer, there would be several types of syn-metallogenic fissure subsystems, in which veins of metallogenic period usually fill. Because the strength of effort at the center is much stronger than that at the surrounding places, the pre-existent and the self-propagated fractures show regular spatial patterns both in density and in direction, which determine the kinematics of fluids. So the density of dikes and their stretching directions can be considered as quantitative indexes to target the potential locations in which ore-bearing fluids are extensively cumulated, and mineralization occurs. Using moving-average method to get the contours of the dike densities and the dike stretching directions, the authors regard the maximums as the prediction targets. The result is highly consistent with that analyzed by the geological method. Therefore the quantitative method offered in this paper is effective.