Geochronological and geochemical constraints on the genesis of the Huanren skarn Cu–Zn deposit, northeast China

Abstract

The Huanren skarn Cu–Zn deposit is located in southeastern Liaoning on the eastern edge of the North China Craton (NCC). In this paper, we present a study on the geochronologic, geochemical and Sr–Nd–Hf and S isotopic data for the magmatic rocks and sulfide minerals exposed in the deposit. Laser ablation inductively coupled plasma mass spectrometry (LA–ICP–MS) dating of zircon grains from two mining pits in the monzodiorite yields ages of 128.2 ± 1.1 Ma and 128.6 ± 1.5 Ma; these results indicate that the magmatism in the Huanren Cu–Zn deposit might have occurred in the Early Cretaceous. Geochemically, the Huanren monzodiorite belongs to the high-K calc-alkaline and shoshonitic series, is enriched in Rb, Ba, and K and is depleted in Nb, Ta, and Ti. The rocks also have relatively high (87Sr/86Sr)i (0.7091–0.7099) and low εNd(t) (−13.2 to − 10.3) and εHf(t) values (−14.3 to − 7.8). The Sr–Nd–Hf isotopic data for the monzodiorite indicate that the magma may be derived from mixed sources of the crust and mantle. The δ34S values of chalcopyrite, galena and pyrite range from 4.4‰ to 5.8‰, with an average of 5.1‰, indicating that the sulfur in the deposit was mainly derived from a magmatic source. The Huanren Cu–Zn deposit resulted from the magmatism and mineralization induced by the rollback of the Paleo-Pacific Plate.