Primary halo superimposition model and deepprospecting potential evaluation of the Dongjianian silver deposit in western Henan

The primary halo superimposition model has significant indicative significance for determining mineral species, scale, and burial depth of concealed ore bodies. The Dongjianian silver deposit, classified as a medium-low temperature hydrothermal deposit, was systematically investigated through primary halo sampling and analysis. This study reveals distinct lateral and axial halo characteristics, identifying inner halo elements (Ag, Sb, Pb, Zn, Au), intermediate halo elements (As, Cu), and outer halo elements (Mo, Co, Bi) based on surface primary halo concentration gradients. According to the elemental characteristics along the No.00 exploration line, the axial zoning sequence is determined as W-Co-Pb-As-Cu-Sb-Ag-Mo-Bi-Zn-Au, showing a reverse zoning pattern. The established primary halo superimposed model reveals coexisting leading and trailing halos at the distal end of deep ore bodies. The primary halo characteristics indicate potential concealed Au and Ag ore bodies at the 290 m intermediate level and greater depths, demonstrating significant deep prospecting potential.