Abstract:

Based on the studies of the geological and geochemical characteristics, the genesis of the Dongjun lead-zinc-silver deposit in Inner Mongolia was discussed in this paper.Geochemical studies showed that the magmatic rocks belong to the calc-alkaline series, and their light rare earth and large ion lithophile elements are both relative enrichment.REE distribution modes are similar between ore and magmatic rocks, the content of K, Th, U and Rb elements showed obviously positive anomalies among the ore, altered rock, volcanic rocks and monzonite porphyry.On the contrary, the content of elements Ta and Nb showed negative anomalies.These indicated all kinds of rocks, have the same provenance in the deposit, were derived from the enriched mantle enriching large ion lithophile elements with a contamination of a little crustal material.Pb and S isotope studies of the metal sulfides showed the oreforming materials were derived from magma system.According to the studies of the geological and geochemical characteristics, the Dongjun Pb-Zn-Ag deposit was considered to be a hydrothermal vein type deposit related to volcanic-subvolcanic magmatism.The mineralization is closely related to Mesozoic volcanic magmatism.The NW and NE trending fractures are the ore-bearing and ore-controlling structures.

Key words: lead-zinc-silver deposit, geological characteristic, genesis, Dongjun, Inner Mongolia