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The Dongpuzi deposit is an epithermal gold deposit located in the southern margin of the Shaozihe volcanic fault basin in the Liaodong Peninsula. On the basis of fluid inclusion and C–H–O–S–Pb isotope data, a metallogenic model is established for the Dongpuzi deposit. The mineralization at the Dongpuzi deposit has experienced quartz–pyrite (I), quartz–sulfide (II), and quartz–calcite (III) stages. The quartz from ore stage II has liquid-dominated aqueous inclusions, which have homogenization temperatures ranging from 113 to 162 °C and salinities varying from 3.2 to 9.6 wt% NaCl equiv. The quartz from the quartz–calcite stage has decreasing homogenization temperatures (106~143 °C) and salinities (2.7~6.9 wt% NaCl equiv.). The fluid inclusion data indicate that the gold ores were precipitated from low-temperature and low-salinity solutions, with an obvious decrease in temperature and salinity from ore stages II to III. The calculated δ18Owater values for the quartz of ore stage II range from −14.71‰ to −13.31‰, and the corresponding δDwater values range from −103.3‰ to −96.1‰, indicating that the ore-forming fluids could be of a meteoric origin. The calcite from ore stage III has δ13CV-PDB values of −4.5‰ to −4.2‰ and δ18OV-SMOW values of +7.0‰ to +7.4‰, indicating a mantle source for the carbon. The pyrite yielded δ34S values of +4.1‰ to +6.6‰ and Pb isotopes consistent with those of the host trachyte porphyry and volcanic rocks of the Xiaoling Formation, which suggests that the S and Pb in gold ores were dominantly derived from the host trachyte porphyry and volcanic rocks of the Xiaoling Formation, with some combination of Paleoproterozoic metamorphic rocks of the Gaixian Formation. These results, together with the ore geology, indicate that the Dongpuzi deposit is a typical low-sulfidation epithermal gold deposit with important ore-forming materials input from the host trachyte porphyry, volcanic rocks of the Xiaoling Formation, and Paleoproterozoic metamorphic rocks of the Gaixian Formation. The Dongpuzi deposit was formed under an extensional setting related to the Early Cretaceous lithospheric extension and thinning of the eastern North China Craton. [ABSTRACT FROM AUTHOR]

A Paleoproterozoic 40Ar/39Ar 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 δ34S composition of the auriferous pyrite varies from +8‰ to +12.3‰, 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. 40Ar/39Ar dating of these tremolite samples yields a plateau age of ~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. [ABSTRACT FROM AUTHOR]

The Erdaogou gold deposit is located in the conjuncture of North China Carton and Xingmeng orogenic belt. The ore-forming process of Erdaogou gold deposit is divided into three stages (I to III), which are quartz-pyrite stage (stage I), quartz-polymetallic sulfide stage (stage II) and quartz-calcite stage (stage III). Two types of fluid inclusions is distinguished in the ore-forming stage, i.e., aqueous type (W-type) and aqueous-carbonic type (C-type) inclusions. From the stage I to III, the homogenization temperature of fluid inclusions are respectively 334–395, 214–364 and 172–272 °C, with salinities of 7.72 wt.%–11.23 wt.% NaCl equiv., 0.20 wt.%–23.18 wt.% NaCl equiv., and 0.35 wt.% to 5.25 wt.% NaCl equiv. The ore-forming fluids of the Erdaogou deposit have the characteristics of medium-low temperatures, moderate salinities and low densities. And the fluids belong to the CO2-H2O-NaCl system. The values of δ34SV-CDT in sulphide samples at different stages (stages I to III) are between −2.2‰ to 2.3‰, indicating sulfur source from magma volatiles or subvolcanic rock leaching. The lead isotopes suggest that ore-forming metals may be derived from a mixture of lower crust and mantle materials. Oxygen and hydrogen isotope data at Erdaogou indicate that magmatic fluid and meteoric water may both be involved in the hydrothermal system. Based on the geological characteristics, fluid inclusion results, stable and radiogenic isotope results of Erdaogou gold deposit, we believe that the temperature decrease, fluid boiling are the key factors leading to the ore precipitation and the genetic type of Erdaogou gold deposit is low-sulfidation epithermal deposit. [ABSTRACT FROM AUTHOR]

[Display omitted] • The Xinfang gold deposit is classified as an Early Cretaceous magmatic-hydrothermal gold deposit. • C-O-Si isotopes indicate magmatic water for ore-forming fluids. • He-Ar isotopes suggest that the ore-forming fluids were of a crustal source with a minor mantle. • S-Pb isotopes indicate a deep-seated magma for ore metals. The Xinfang gold deposit (>20 t@ 2.85 g/t) is situated in the southwest of the Liaodong Peninsula. Ore bodies are hosted by the Archean gneiss in the footwall and Neoproterozoic metasandstone in the hangingwall of the Xinfang Metamorphic Core Complex. Here, we conduct pyrite Re-Os dating, C, O, Si, He-Ar, S, and Pb isotopes in order to constrain the ore-forming age and genesis of the deposit. Field observations show that three ore-forming processes are recognized: (1) quartz- coarse-grained pyrite stage (stage Ⅰ), (2) quartz-polymetallic sulfide-gold stage (stage Ⅱ), and (3) quartz – calcite ± pyrite stage (stage III). Pyrite from the quartz-polymetallic sulfide-gold vein yielded Re-Os isochron age of 121.1 ± 1.2 Ma (Initial 187Os/188Os = 1.49 ± 0.01, MSWD = 1.2), which is interpreted to be the ore-formation age.Theδ13C V-PDB and 18O v-SMO W values of calcite from stage III range from −5.1‰ to −4.9‰ and from 9.7‰ to 10.1‰, and the δ30Si values of quartz from stage Ⅰto stage III range from −0.5‰ to −0.4‰, −0.1‰ to −0.3‰, and −0.2‰ to −0.1‰, respectively, indicating that ore-forming fluids were derived from a magmatic-hydrothermal source. Sulfur isotopic compositions of sulfides between −1.9 ‰ and 4.4 ‰ (mean = 2.4 ‰), are consistent with that of magmatic sulfur. The galena yielded a wide range of lead isotopic composition (206Pb/204Pb = 16.995–17.252, 207Pb/204Pb = 15.335–16.343, 208Pb/204Pb = 37.461–37.580) suggesting an external lead source. The He and Ar isotope compositions of pyrite and galena (3He/4He = 0.14Ra-0.62Ra), indicate a crustal source with minor mantle contributions. Combining all available data results, we propose that a magmatic -hydrothermal source for the Xinfang gold deposit and the ore formation was related to the subduction of the Paleo-Pacific Plate beneath Eurasia. [ABSTRACT FROM AUTHOR]