Paleoproterozoic Mineralization of the Lijiapuzi Gold Deposit in the Liaodong Peninsula, NE China: Constraints from Ar-40-Ar-39 Age, S-Pb Isotopes, and In Situ Analyses

A Paleoproterozoic Ar-40/Ar-39 age, interpreted as the gold metallogenic epoch of the Lijiapuzi deposit in NE China, is reported in this paper. The ore body of this deposit is hosted in the marbles and schists of the Paleoproterozoic Dashiqiao Formation and exhibits parallel development to the foliation of the country rocks. Coexisting auriferous pyrite and tremolite can be observed both in the field and under a microscope, revealing the presence of hydrothermal activity in the deposit. The delta S-34 composition of the auriferous pyrite varies from +8 parts per thousand to +12.3 parts per thousand, indicating a sedimentary origin. The auriferous pyrite and host marble have similar Pb isotopic ratios, indicating the contribution of Paleoproterozoic sediments to gold mineralization. Furthermore, in situ S and trace element analyses of the auriferous pyrite reveal that the main gold mineralization stage was Py2, which coexists with radial tremolite. Ar-40/Ar-39 dating of these tremolite samples yields a plateau age of similar to 1851.23 Ma, with similar isochronal and inverse isochronal ages. The Paleoproterozoic gold metallogenesis, together with the contemporary Pb-Zn, boron, graphite, and magnetite mineralization, constitute an important mineralogenetic series during the evolution of the Jiao-Liao-Ji orogeny in the Liaodong Peninsula.