In the southeast part of the North-Asian craton, several ring basite-ultrabasite plutons have been recognized, with which the commercial placers of platinoids associate. Analysis of the known geodynamic models of the region formation and materials of seismic tomography showed that the subduction processes, that actively manifested themselves in the Asia-Pacific convergence zone in Mesozoic, were responsible for initiation of the stagnated oceanic slab. Its NE and SW boundaries appear to coincide with the transform faults. Projection of the transform fault, bordering the above mentioned slab in the NEN, coincides with the Konder-Feklistovsky metallogenic belt distinguished earlier and its Aldan (Inaglinsky) member. Higher platinum content of ring massifs of the belt is controlled by the influence of the lower mantle derivatives on the ascending upper mantle plumes. In the southeast part of the North-Asian craton, several ring basite-ultrabasite plutons have been recognized, with which the commercial placers of platinoids associate. Analysis of the known geodynamic models of the region formation and materials of seismic tomography showed that the subduction processes , that an operating manifested themselves in the Asia-Pacific convergence zone in Mesozoic, were responsible for initiation of the stagnated oceanic slab. Its NE and SW boundaries appear to coincide with the transform faults. Projection of the transform fault, bordering the said mentioned slab in the NEN, coincides with the Konder-Feklistovsky metallogenic belt distinguished earlier and its Aldan (Inaglinsky) member. Higher platinum content of ring massifs of the belt is controlled by the influence of the lower mantle derivatives on the ascending upper mantle plumes.