Ore Genesis at the Jinchang Gold–Copper Deposit in Heilongjiang Province, Northeastern China: Evidence from Geology, Fluid Inclusions, and H–O–S Isotopes

Abstract

The Jinchang gold–copper deposit is located in Eastern Heilongjiang Province,Northeastern China. The orebody comprises primarily hydrothermal breccias, quartz veins, anddisseminated ores within granite, diorite, and granodiorite. Three paragenetic stages are identified:early quartz–pyrite–arsenopyrite (Stage 1), quartz–pyrite–chalcopyrite (Stage 2), and latequartz–pyrite–galena–sphalerite (Stage 3). Gold was deposited during all three stages and Stage 1was the major gold-producing stage. Copper is associated with the mineralization but has loweconomic value. Fluid inclusions (FIs) within the deposit are liquid-rich aqueous, vapor-rich aqueous,and daughter-mineral-bearing types. Microthermometric data for the FIs reveal decreasinghomogenization temperatures (Th) and salinities of the ore-forming fluids over time. The Th forStages 1–3 of the mineralization are 421–479, 363–408, and 296–347 °C, respectively. Stage 1 fluidsin vapor-rich and daughter-mineral-bearing inclusions have salinities of 5.7–8.7 and 49.8–54.4 wt%NaCl equivalent, respectively. Stage 2 fluids in vapor-rich, liquid-rich, and daughter-mineral-bearinginclusions have salinities of 1.2–5.4, 9.5–16.0, and 43.3–48.3 wt% NaCl, respectively. Stage 3 fluids inliquid-rich and daughter-mineral-bearing inclusions have salinities of 7.9–12.6 and 38.3–42.0 wt% NaClequivalent, respectively. The estimated trapping pressures are 160–220 bar, corresponding toan entrapment depth of 1.6–1.2 km in the paleo-water table. Oxygen and hydrogen isotope data(δ18OV-SMOW = 8.6‰ to 11.4‰; δDV-SMOW = −92.2‰ to −72.1‰) suggest that the ore-forming fluidswere derived from magmatic fluids during the early stages of mineralization and subsequentlyincorporated meteoric water during the late stages. The sulfide minerals have δ34SVCDT values of0.2‰–3.5‰, suggesting that the sulfur has a magmatic origin. The Jinchang deposit is a typicalgold-rich gold–copper porphyry deposit.

Fluid Evolution and Ore Genesis of the Qibaoshan Polymetallic Ore Field, Shandong Province, China: Constraints from Fluid Inclusions and H–O–S Isotopic Compositions

“…The partitioning of fluid into vapor-rich high-salinity fluids was caused by the boiling of parental magmatic fluids ( Figure 10). 3Most of the S-type FIs were homogenized by the simultaneous disappearance of the vapor phase and daughter minerals [39]. The homogenization temperatures of the boiling inclusions were close to the quartz crystallization temperatures, which were similar to the ore formation temperatures of the Jinxiantou and Changgou deposits.…”

“…The partitioning of fluid into vapor-rich high-salinity fluids was caused by the boiling of parental magmatic fluids ( Figure 10). (3) Most of the S-type FIs were homogenized by the simultaneous disappearance of the vapor phase and daughter minerals [39].…”

Mineralogy, Fluid Inclusions, and Isotopic Study of the Kargah Cu-Pb Polymetallic Vein-Type Deposit, Kohistan Island Arc, Northern Pakistan: Implication for Ore Genesis

“…A magmatic source in hydrothermal deposits implies that the δ 34 S values are near (0 ± 3‰) [98,99]. Previous studies have revealed that the sulfur isotopic composition of sulfide minerals depend on the δ 34 S of source materials, and also on the physicochemical condition (pH value, temperature, ion activity, and oxygen fugacity), as well as the evolution of the hydrothermal fluids [100,101]. The δ 34 S variation in the magmatic-hydrothermal deposit is also caused by magma contamination via interactions with country rocks, and typically assigned to the assimilation of sulfur from the wall rocks [97].…”

“…Figure 15. Sulfur isotopic compositions of the Kargah Cu-Pb polymetallic deposit as compared with the magmatic-hydrothermal deposits and other geological settings, (after [9,43,44]); data of the Erdaokan Ag-Pb-Zn deposit from Yuan et al [43]; Bianjiadayuan Ag-Pb-Zn deposit from Zhai et al [104]; Jiawula Ag-P-Zn deposit from Niu et al [85] ; Sandaowanzi deposit from Zhai et al [105]; Jinchang Gold-Copper deposit from Li et al [100]; Baoshan, Shuikoushan, and Kangjiawan Pb-Zn deposits from Zou [109]; Yongxin deposit from Yuan et al [44]. [9,43,44]); data of the Erdaokan Ag-Pb-Zn deposit from Yuan et al [43]; Bianjiadayuan Ag-Pb-Zn deposit from Zhai et al [104]; Jiawula Ag-P-Zn deposit from Niu et al [85]; Sandaowanzi deposit from Zhai et al [105]; Jinchang Gold-Copper deposit from Li et al [100]; Baoshan, Shuikoushan, and Kangjiawan Pb-Zn deposits from Zou [109]; Yongxin deposit from Yuan et al [44].…”

Editorial for Special Issue “Fluid Inclusion Characteristic of the Gold Deposit and Its Implication for Ore Genesis”

“…The primary fluid inclusions trapped during the mineralization stages are H 2 O-NaCl, unsaturated, and homogenize either to the vapor or to the liquid with Th of 300-430 • C, their salinity is 2-16 wt % NaCl equiv. and the density is 0.43 to 0.94 g/cm 3 . Although Tocantinzinho shows similarities with magmatic-hydrothermal oxidized calc-alkaline granite-related gold deposits classified as porphyry gold deposits, it has been classified with porphyry-style gold deposits, because it lacks some features of Phanerozoic porphyry-type deposits.…”