Constraints of the lead isotope geochemical field of the Upper Mantle in China on diagenetic and ore-forming materials exemplified by porphyry copper deposit and copper-nickel sulfide deposit

The lead stable isotope geochemistry of regional metallogenic belts is an effective means for making regional geochemical zoning, tracing diagenetic ore-forming sources, and elucidating the genesis of deposits. Based on the unique tectonic setting of China, the authors have traced the diagenesis of large-sized and superlarge porphyry copper deposits and copper-nickel sulfide deposits in China based on the geochemical field of the lead isotope composition of the upper mantle in China for sources of ore-forming materials. Some conclusions have been reached:1. The porphyry copper deposit and the copper-nickel sulfide type ore-forming parent rock inherit the lead isotope composition of the upper mantle of the adjacent land mass; 2. The lead isotope composition of the ore-bearing rock mass and ore minerals of the two types of deposits is obviously consistent with each other, and the two traces are homologous; the lead isotope composition of the shell fused granite and surrounding strata is different from that of the ore; 3. In addition to inheriting different lead isotope composition characteristics of the mantle on each land mass, the lead isotope composition of rock and ore in the porphyry copper deposits and the copper-nickel sulfide deposits of each land mass also trace the "block effect" of the coupling between the crust and the mantle layers. At the same time, the lead isotope composition of the upper mantle may exhibits "delay effect".