Evolution of Multistage Hydrothermal Fluids in the Luoboling Porphyry Cu-Mo Deposit, Zijinshan Ore Field, Fujian Province, China: Insights from LA-ICP-MS Analyses of Fluid Inclusions

2020 ◽  
Author(s):  
Xiao-Yu Zhao ◽  
Hong Zhong ◽  
Rui-Zhong Hu ◽  
Wei Mao ◽  
Zhong-Jie Bai ◽  
...  
Keyword(s):  
Fluid Inclusions ◽  
Hydrothermal Systems ◽  
Hydrothermal Fluids ◽  
Common Source ◽  
Two Phase ◽  
Porphyry Cu ◽  
Icp Ms ◽  
High Concentrations ◽  
Granodiorite Porphyry ◽  
Increasing Trends

Abstract The Luoboling Cu-Mo deposit, with 1.4 million tons (Mt) Cu and 0.11 Mt Mo, is the largest porphyry deposit in the Zijinshan district of southeast China. Mineralization at Luoboling is divided into premineralization, synmineralization, and late-mineralization stages. Consistent Cs/(Na + K) ratios in fluid inclusions suggest that the mineralizing fluids originated from a common source—the Luoboling granodiorite porphyry. The absence of initial supercritical fluid inclusions and abundant coexisting vapor and brine fluid inclusions imply that the fluids exsolved at low-pressure two-phase conditions, with temperatures of 250° to 600°C and salinities of 30 to 60 wt % NaCl equiv (brines) and <10 wt % NaCl equiv (vapors). The deposit formed at ~120 to 800 bar, corresponding to the depths of ~1.2 to 3.2 km (assuming a transition from lithostatic to hydrostatic load). Metals such as Mo (up to 77 ppm), Pb (up to 8,800 ppm), Zn (up to 13,000 ppm), and Ag (up to 130 ppm) migrated mainly in brines. Although vapor inclusions have high concentrations of Cu (up to 20,000 ppm), hypersaline fluid was the major medium for Cu transport and precipitation. The successive precipitation of Mo and Cu occurred when fluids cooled to ~500°C and ~350° to 450°C, respectively. The late-stage quartz-pyrite veins with phyllic alteration were formed by Cu-rich magmatic hydrothermal fluids. The Zijinshan epithermal Cu-Au deposit and the Luoboling porphyry Cu-Mo deposit originated from independent hydrothermal systems. Nonetheless, the increasing trends of Pb, Zn, and Ag concentrations in different stage inclusions from Luoboling imply potential for distal Pb-Zn-Ag mineralization.

scholarly journals Geological, Geochronological, and Geochemical Insights into the Formation of the Giant Pulang Porphyry Cu (–Mo–Au) Deposit in Northwestern Yunnan Province, SW China

Minerals ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 191 ◽  
Author(s):  
Qun Yang ◽  
Yun-Sheng Ren ◽  
Sheng-Bo Chen ◽  
Guo-Liang Zhang ◽  
Qing-Hong Zeng ◽  
...  
Keyword(s):  
Rare Earth ◽  
Rare Earth Elements ◽  
Yunnan Province ◽  
Oceanic Lithosphere ◽  
Late Triassic ◽  
Porphyry Cu ◽  
Icp Ms ◽  
Heavy Rare Earth Elements ◽  
Granodiorite Porphyry ◽  
Northwestern Yunnan

The giant Pulang porphyry Cu (–Mo–Au) deposit in Northwestern Yunnan Province, China, is located in the southern part of the Triassic Yidun Arc. The Cu orebodies are mainly hosted in quartz monzonite porphyry (QMP) intruding quartz diorite porphyry (QDP) and cut by granodiorite porphyry (GP). New LA-ICP-MS zircon U–Pb ages indicate that QDP (227 ± 2 Ma), QMP (218 ± 1 Ma, 219 ± 1 Ma), and GP (209 ± 1 Ma) are significantly different in age; however, the molybdenite Re–Os isochron age (218 ± 2 Ma) indicates a close temporal and genetic relationship between Cu mineralization and QMP. Pulang porphyry intrusions are enriched in light rare-earth elements (LREEs) and large ion lithophile elements (LILEs), and depleted in heavy rare-earth elements (HREEs) and high field-strength elements (HFSEs), with moderately negative Eu anomalies. They are high in SiO2, Al2O3, Sr, Na2O/K2O, Mg#, and Sr/Y, but low in Y, and Yb, suggesting a geochemical affinity to high-silica (HSA) adakitic rocks. These features are used to infer that the Pulang HSA porphyry intrusions were derived from the partial melting of a basaltic oceanic-slab. These magmas reacted with peridotite during their ascent through the mantle wedge. This is interpreted to indicate that the Pulang Cu deposit and associated magmatism can be linked to the synchronous westward subduction of the Ganzi–Litang oceanic lithosphere, which has been established as Late Triassic.

Compositions of magmatic hydrothermal fluids determined by LA-ICP-MS of fluid inclusions from the porphyry copper–molybdenum deposit at Butte, MT

2004 ◽  
Vol 210 (1-4) ◽  
pp. 173-199 ◽  
Author(s):  
Brian G. Rusk ◽  
Mark H. Reed ◽  
John H. Dilles ◽  
Leonhard M. Klemm ◽  
Christoph A. Heinrich
Keyword(s):  
Fluid Inclusions ◽  
Porphyry Copper ◽  
Hydrothermal Fluids ◽  
Icp Ms ◽  
Molybdenum Deposit

Fluid Inclusion Study on the Duobaoshan Porphyry Deposit and Sankuanggou Skarn Deposit, Heilongjiang, China

2014 ◽  
Vol 962-965 ◽  
pp. 41-44
Author(s):  
Hao Wei ◽  
Jiu Hua Xu ◽  
Guo Rui Zhang
Keyword(s):  
Fluid Inclusion ◽  
Fluid Inclusions ◽  
Hydrothermal Fluid ◽  
Field Data ◽  
Hydrothermal Fluids ◽  
Fluid Inclusion Study ◽  
Skarn Deposit ◽  
Porphyry Deposit ◽  
Porphyry Cu ◽  
Inclusion Study

In this paper we use new field data, fluid inclummsions, and table isotopes (O, H, and S) to refine the roles of the hydrothermal evolution, evaluate changes in the hydrothermal fluids of Duobaoshan porphyry Cu (Mo) deposit and Sankuanggou skarn Fe-Cu deposit. Four ore-forming stages are recognized at The Duobaoshan porphyry Cu (Mo) deposit. Fluid inclusions are abundant in quartz of various stages. Estimated trapping pressures for stage I, II, III are 110-160MPa, 58-80MPa, and 8-17MPa, corresponding trapping temperatures are 375-650°C, 310-350°C, 210-290°C. The δD and δ18O values of fluids indicate a evolution process from magmtic hydrothermal fluid to a mixing magmtic and meteoric fluid. The δ34S values of sulfides mainly suggest predominantly source of deep magma chamber.

Reaction between Cu-bearing minerals and hydrothermal fluids at 800 °C and 200 MPa: Constraints from synthetic fluid inclusions

2020 ◽  
Vol 105 (8) ◽  
pp. 1126-1139
Author(s):  
Dongmei Qi ◽  
Harald Behrens ◽  
Roman Botcharnikov ◽  
Insa Derrey ◽  
Francois Holtz ◽  
...  
Keyword(s):  
Fluid Inclusions ◽  
Pure Water ◽  
Metallic Copper ◽  
Pressure Vessels ◽  
Hydrothermal Systems ◽  
Hydrothermal Fluids ◽  
Silicate Melt ◽  
Fluid Composition ◽  
Nacl Solution ◽  
Synthetic Fluid Inclusions

Abstract Transport and deposition of copper in the Earth's crust are mainly controlled by the solubility of Cu-bearing phases and the speciation of Cu in magmatic-hydrothermal fluids. To improve our understanding of copper mobilization by hydrothermal fluids, we conducted an experimental study on the interaction between Cu-bearing phases (metallic copper, Cu2O, CuCl) and aqueous chloride solutions (H2O ± NaCl ± HCl; with Cl concentrations of 0 to 4.3 mol kg-1). The experiments were run in rapid heat/rapid quench cold-seal pressure vessels at 800 °C, 200 MPa, and logfO2 ~ NNO+2.3. Either Cu or Au capsules were used as containers. The reaction products were sampled in situ by the entrapment of synthetic fluid inclusions in quartz. Fluid composition was subsequently determined by analyzing individual fluid inclusions using a freezing cell and laser ablation inductively coupled plasma-mass spectrometry. Our results show that large isolated and isometric inclusions, free of late-stage modifications, can be preserved after the experiment even when using a high cooling rate of 25 K s-1. The obtained results demonstrate that: (1) reaction between native Cu, NaCl solution, and quartz (± silica gel) leads to the coexistence of fluid inclusions and Na-bearing silicate melt inclusions. Micrometer-to submicrometer-sized cuprite (Cu2O) crystals have been observed in both types of the inclusions, and they are formed most probably due to the dissociation of CuOH. (2) When Cu0 reacts with HCl and CuCl solutions, or Cu+ reacts with NaCl solution, nantokite (CuCl) formed due to oversaturation has been found in fluid inclusion. Copper concentration in the fluid shows a strong positive dependence on the initial chlorine content, with Cu/Cl molal ratios varying from 1:9 to 1:1 in case 1 and case 2, respectively. When Cl is fixed to 1.5 m, initial fluid acidity has a major control on the Cu content, i.e., 0.17 ± 0.09 and 1.29 ± 0.57 m Cu were measured in fluids of case 1 and case 2, respectively. Cu solubility in pure water and in 1.5 m NaCl solutions are 0.004 ± 0.002 and 0.16 ± 0.07 m, respectively. The main responsible Cu-bearing complexes are CuOH(H2O)x in water, NaCuCl2 in NaCl solutions and HCuCl2 in alkali-free solutions. These results provide quantitative constraints on the mobility of Cu in hydrothermal solutions and confirm that Cl is a very important ligand responsible for Cu transport. The first observation that silicate melt can be generated in the fluid-dominated and native-copper-bearing system implies that transitional thermosilicate liquids can coexist with metal-rich fluids and may enhance Cu mobility in magmatic-hydrothermal systems. This may have important implications for the formation of Cu deposits in the systems with low S activities.

scholarly journals Apatite fingerprints on the magmatic-hydrothermal evolution of the Daheishan giant porphyry Mo deposit, NE China

2021 ◽  
Author(s):  
Pan Qu ◽  
Wubin Yang ◽  
Hecai Niu ◽  
Ningbo Li ◽  
Dan Wu
Keyword(s):  
Hydrothermal Alteration ◽  
Fluid Inclusions ◽  
Wall Rock ◽  
Hydrothermal Fluids ◽  
Ne China ◽  
Porphyry Deposits ◽  
Icp Ms ◽  
Porphyry System ◽  
Porphyry Mo Deposit ◽  
Porphyry Systems

Porphyry deposits are the main source for global Cu and Mo production. The generation of hydrous silicate magmas and subsequent separation of volatile-rich magmatic fluids with hydrothermal alteration are significant processes leading to the formation of porphyry deposits. However, a specific understanding of these processes has been limited by a lack of direct mineralogical records in the evolving magmatic-hydrothermal system. In this paper, we present an integrated textural and geochemical investigation on apatite from the giant Daheishan porphyry Mo deposit in NE China, illustrating that apatite can be a potential recorder of the magmatic-hydrothermal evolution of porphyry systems. Apatite from the ore-forming porphyry displays distinctive core-rim textures, with melt inclusions in the resorption cores (Type-A1) and co-existing of melt and fluid inclusions in the euhedral rims (Type-A2), indicating a magmatic-hydrothermal origin of apatite. This is also supported by both chemical and isotopic compositions obtained by in situ analyses using laser ablation−inductively coupled plasma−mass spectrometry (LA-ICP-MS) and LA-multi collector-ICP-MS. The late Type-A2 apatite is relatively enriched in incompatible elements, such as rare earth elements (REE) and Th, but slightly depleted in fluid-mobile elements such as Na and S, compared to the early Type-A1 apatite. Relatively homogeneous (87Sr/86Sr)i ratios (0.70436−0.70504) of the Type-A1 and Type-A2 apatites indicate that they were formed in a relatively closed system without detectable contamination. Meanwhile, some apatite in the wall rock (biotite granodiorite) shows characteristics of secondary altered textures, resulting from the intensive alteration by hydrothermal fluids exsolved from the porphyry system. Apatite trapped in mineral phenocrysts of the wall rock is usually unaltered (Type-B1 apatite), with clear oscillatory growth zones in cathodoluminescence (CL) images. In contrast, the intergranular apatite is commonly altered (Type-B2 apatite), with chaotic zoning in CL images, abundant micro-fractures and secondary fluid inclusions. Compositionally, the Type-B2 apatite shows notable tetrad REE patterns, relatively lower light-REE and S contents, and elevated 147Sm/144Nd ratios compared to the Type-B1 apatite. LA-ICP-MS U-Pb dating yields a lower intercept age of 171.4 ± 2.3 Ma for Type-B2, which is consistent with the age of 171.5 ± 2.4 Ma for Type-A2, but is notably younger than the Type-B1 apatite (175.5 ± 1.3 Ma). It is suggested that the Type-B2 apatite has been significantly reset by hydrothermal fluids exsolved from the porphyry system. Therefore, we conclude that the textures and geochemistry of apatite in porphyry systems can be used as a potential proxy for recording fluid exsolution and hydrothermal alteration processes.

scholarly journals Reconstruction of Hydrothermal Processes in the Cyprus Type Fe-Cu-Zn Deposits of the Italian Northern Apennines: Results of Combined Fluid Inclusion Microthermometry, SEM-CL Imaging and Trace Element Analyses by LA-ICP-MS

Minerals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 165
Author(s):  
Gabriella B. Kiss ◽  
Zsolt Bendő ◽  
Giorgio Garuti ◽  
Federica Zaccarini ◽  
Edit Király ◽  
...  
Keyword(s):  
Fluid Inclusion ◽  
Trace Element ◽  
Fluid Inclusions ◽  
Massive Sulfide ◽  
Hydrothermal Activity ◽  
Hydrothermal Systems ◽  
Original Position ◽  
Volcanogenic Massive Sulfide ◽  
Hydrothermal Conditions ◽  
Icp Ms

Quartz from the stockwork zone of various Cyprus type volcanogenic massive sulfide deposits (Boccassuolo, Reppia, Campegli, Bargone and Vigonzano) from the unmetamorphosed, Jurassic Northern Apennine ophiolites was studied in order to provide details on the submarine hydrothermal conditions and the characteristics for ore formation. Our detailed SEM-CL investigation of quartz contributed to a robust characterization and interpretation of primary fluid inclusions and microthermometry data. SEM-CL imaging was also useful for reconstructing the consecutive steps of quartz precipitation. The determination of trace element contents according to growth zoning in quartz by LA-ICP-MS constrained the compositional variations of parent fluids during the hydrothermal activity. A continuously cooling fluid regime characterized each studied volcanogenic massive sulfide (VMS) occurrence although the minimum formation temperatures were different (Bargone: 110–270 °C; Boccassuolo: 60–360 °C; Campegli: 110–225 °C; Reppia: 50–205 °C; Vigonzano: 260–330 °C), the range of temperature most probably depends on the original position of sampling in relation to the centers of the hydrothermal systems. Compositional changes are reflected by variations in the methane content (0.13–0.33 mol/kg) and salinity (2.6–9.3 NaCl equiv. wt. %) in the fluid inclusions of quartz and calcite as well as a changeable Al content (11–1526 ppm) in quartz. This study demonstrates that the combined use of SEM-CL imaging and LA-ICP-MS analyses, coupled with fluid inclusion microthermometry, can constrain the different fluid conditions of ore forming and the barren stages of evolving submarine hydrothermal systems.

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