Trace element and isotopic (S, Pb) constraints on the formation of the giant Chalukou porphyry Mo deposit, NE China

Abstract

Porphyry type Mo deposits have supplied most of the Mo to the world. However, the source of the Mo and the controls on its enrichment in such deposits is still a matter of great debate. In this study, we present in situ trace element and isotopic data for a giant porphyry Mo deposit (the Chalukou Mo deposit in NE China) and use these data to address these issues. Three primary paragenetic stages of mineralization were recognized at Chalukou: (I) K-feldspar + quartz + minor pyrite (Py-I) + minor molybdenite (Mol-I); (II) quartz + sericite + molybdenite (Mol-II) + pyrite (Py-II); (III) quartz + chlorite + epidote + fluorite + pyrite (Py-III) + galena + sphalerite + minor chalcopyrite. The bulk of the molybdenite was deposited in Stage II. In situ S isotope analyses of the sulfide ores show that the δ 34 S values vary from -5.2 to +7.8‰ (mean = +2.9‰), and correspond to δ 34 S H2S values from -2.4 to +3.3‰ (mean = +1.1‰). These values are consistent with a magmatic source for the sulfur. In situ Pb isotope compositions of the sulfide ores are almost identical to those of the local Mesozoic granites and other magmatic-hydrothermal ore deposits in this region, suggesting a close genetic association between the Mo mineralization and felsic magmatism.Pyrite from the three stages of mineralization differs significantly in its trace element composition. The first generation, Py-I, has a high Cu content (8.7 ± 49.6 ppm; where the first value is the median and the second is the standard deviation) and Mo content (6.9 ± 3.8 ppm). Pyrite-II has the lowest Cu concentration (1.3 ± 2.1 ppm) and a relatively high Mo concentration (5 ± 128 ppm), and Py-III has a high Cu This is the peer-reviewed, final accepted version for American Mineralogist, published by the Mineralogical Society of America.The published version is subject to change. Cite as Authors (Year) Title. American Mineralogist, in press.

Quartz texture and the chemical composition fingerprint of ore-forming fluid evolution at the Bilihe porphyry Au deposit, NE China

“…The northern margin of the NCC records a complicated series of geodynamic events (e.g., Xiao et al 2003;Zhang et al 2010;Wu et al 2011;Xu B et al 2013;Xu W et al 2013;Wilde 2015), with the formation of numerous different types of ore deposits during subsequent stages of tectonic evolution in the region (Zhao et al 2021a(Zhao et al , 2023Hong et al 2021;Zhai et al 2019Zhai et al , 2020. Widespread Permian intrusive rocks include monzonite, granite porphyry, granodiorite (280 Ma; Zhang et al 2020), biotite adamellite (274-268 Ma;Xiao et al 2012), and minor gabbro (279 Ma;Liu et al 2019).…”

The Occurrence and Chemical Composition of Bismuth-Bearing Minerals in the Niuxingba-Liumukeng Ag-Pb-Zn Deposit, Jiangxi Province, South China

“…Therefore, it is suggested that the granodiorite related to Pb-Zn ore bodies might provide a basis for the source of bismuth in this ore district. Sulfur isotope composition can be used to distinguish different sulfur sources and is widely used to constrain the genesis of mineral deposits [21][22][23]. The sulfur isotope data (−3.8‰ to −1.4‰) for the Niuxingba-Liumukeng deposit reflect a possible magmatic source for the sulfur contained within metal sulfides [5].…”