Mesozoic magmatism and metallogenesis associated with the destruction of the North China Craton: Evidence from U–Pb geochronology and stable isotope geochemistry of the Mujicun porphyry Cu–Mo deposit

The northern flank of the North China Craton (NCC) hosts a linear zone of gold, molybdenum, silver, lead, and zinc polymetallic ore deposits. Among these, the Yingfang Pb-Zn-Ag deposit is located in the central part of the Yanshan–Liaoxi metallogenic belt (YLMB) which extends for approximately 1000 km and forms part of the major mineralized zone. In this study, we characterize the mineralization and trace the ore genesis based on new sulfur and lead isotopic geochemistry and evaluate the timing of mineralization from Rb-Sr isotope dating of sulfides. The pyrite δ34S values range from +3.2‰ to +5.8‰ with a mean at +4.07‰, close to the values of mantle and meteorite sulfur. The 206Pb/204Pb values range from 16.833 to 18.956, 207Pb/204Pb from 15.374 to 15.522, and 208Pb/204Pb from 37.448 to 37.928. Five samples of sulfide, from the Yingfang deposit, yield a Rb-Sr isochron age of 135.7 ± 4.1 Ma. This age is close to the age of the adjacent Niujuan Ag-Au deposit and the associated Er’daogou granite, suggesting a close relationship between magmatism and metallogeny in this region. The S and Pb isotopes of the regional silver polymetallic deposits show similar sources of ore-forming materials. According to a compilation of the available age data on the Mesozoic ore deposits in the northern flank of the NCC, we divide the mineralization into the following four periods: 240–205 Ma, 190–160 Ma, 155–135 Ma, and 135–100 Ma. Mesozoic magmatism and mineralization in the Yingfang deposit mainly took place at 245 Ma and 145–135 Ma. We correlate the Pb-Zn-Ag mineralization to metallogeny associated with large-scale inhomogeneous lithosphere thinning beneath the NCC.

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Tectono-magmatic controls on decratonic gold deposits

Contributions to Mineralogy and Petrology ◽

10.1007/s00410-021-01824-2 ◽

2021 ◽

Vol 176 (9) ◽

Author(s):

Jia Chang ◽

Andreas Audétat ◽

Jian-Wei Li

Keyword(s):

Numerical Modeling ◽

Early Cretaceous ◽

North China Craton ◽

North China ◽

Melt Inclusions ◽

Mineral Exploration ◽

Gold Deposits ◽

Porphyry Cu ◽

The North ◽

Icp Ms

AbstractMagmatic-hydrothermal gold–copper deposits in post-subduction settings represent essential targets for mineral exploration, but controls on their formation remain controversial. The early Cretaceous lode Au districts that formed during lithosphere destruction of the North China Craton provide an ideal opportunity to better understand the key tectono-magmatic factors responsible for the genesis of Au-rich deposits in post-subduction settings. Here, we present a LA-ICP-MS study of silicate melt inclusions and sulfide inclusions from ore-related mafic to intermediate rocks in the central Taihangshan Au district in the interior of the North China Craton to constrain the content and evolution of magmatic ore metals ± volatiles. The results, combined with numerical modeling, suggest that the ore-related magmas contained only a few ng/g Au, which is similar to the Au content of non-mineralization-related mafic to intermediate magmas worldwide. The low Au content of the lode Au-related magmas suggest that large volumes of magmas had to accumulate in the middle to lower crust through trans-lithospheric fault systems to produce the lode Au deposits. It is further suggested that the lode Au-related magmas were alkali-rich, hydrous, oxidized and relatively rich in sulfur and chlorine (mafic melt inclusions contain 0.14‒0.24 wt% S and 0.1‒0.2 wt% Cl). These properties are considered critical for the generation of auriferous ore fluids. By comparing the tectono-magmatic setting of the giant Jiaodong Au province (~ 4000 t Au) with the central Taihangshan district (~ 150 t Au), we propose that the much larger total Au tonnage of the Jiaodong district results from the accumulation of a much larger volume of ore-forming magmas at deep crustal levels, induced by a stronger degree of lithosphere modification. In addition, given that the composition of lode Au-related magmas is similar to that of porphyry Cu–Au-related magmas, the lack of giant, early Cretaceous porphyry Cu–Au deposits in the North China Craton suggests that strong extensional settings favor the formation of lode Au deposits instead of porphyry Cu–Au deposits. The present study, therefore, has general implications for the genesis of Au-rich deposits in strongly extensional settings.

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The Beiminghe skarn iron deposit, eastern China: Geochronology, isotope geochemistry and implications for the destruction of the North China Craton

Lithos ◽

10.1016/j.lithos.2012.11.003 ◽

2013 ◽

Vol 156-159 ◽

pp. 218-229 ◽

Cited By ~ 51

Author(s):

Jun-Feng Shen ◽

M. Santosh ◽

Sheng-Rong Li ◽

Hua-Feng Zhang ◽

Na Yin ◽

...

Keyword(s):

North China Craton ◽

North China ◽

Isotope Geochemistry ◽

Eastern China ◽

Iron Deposit ◽

The North

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New constraints on the genesis and geodynamic setting of the Wulong gold deposit, Liaodong Peninsula, northeast China: evidence from geology, geochemistry, fluid inclusions, and C–H–O–S–Pb isotopes

Canadian Journal of Earth Sciences ◽

10.1139/cjes-2018-0067 ◽

2020 ◽

Vol 57 (3) ◽

pp. 307-330 ◽

Cited By ~ 2

Author(s):

Xihui Cheng ◽

Jiuhua Xu ◽

Fuquan Yang ◽

Guorui Zhang ◽

Hui Zhang ◽

...

Keyword(s):

Gold Deposit ◽

Fluid Inclusions ◽

North China Craton ◽

North China ◽

Isotope Geochemistry ◽

Liaoning Province ◽

Geodynamic Setting ◽

Main Stage ◽

The North ◽

Lode Gold Deposit

The Wulong lode gold deposit is located in the Liaoning Province, northeast part of North China Craton. Gold ore bodies are mainly hosted in the Late Jurassic granite and structurally controlled by northeast-trending faults. Gold occurs in disseminated and auriferous quartz–sulfide veins and veinlets within hydrothermally altered rocks. Mineralization can be divided into three stages: (1) quartz–pyrite stage, (2) quartz–polymetallic sulfides stage, and (3) quartz–carbonate stage. Gold formed mainly in the middle stage. Quartz formed in the two earlier stages contains three compositional types of fluid inclusions, i.e., pure CO2, CO2–H2O and NaCl–H2O, but the late-stage minerals only contain NaCl–H2O inclusions. The inclusions in quartz formed in the early, main, and late stages yield total homogenization temperatures of 317–383 °C, 260–380 °C and 159–234 °C, respectively, with salinities of 5.14–9.44, 2.95–6.20, 1.23–4.34 wt% NaCl equivalent, respectively. Trapping pressures estimated from CO2–H2O inclusions are 200–390 MPa in the main stage. Fluid boiling and immiscibility caused rapid precipitation of sulfides and gold. Through immiscibility and inflow of meteoric water, the ore-forming fluid system evolved from CO2-rich to CO2-poor in composition, and from magmatic to meteoric, as indicated by δ18Owater values (4.5‰–7.3‰). The carbon (−12.2‰ to −11.5‰), sulfur (0.9‰–2.6‰), and lead isotope (207Pb/204Pb of 15.606–15.618) compositions suggest the host rocks to be a significant source of ore metals. Integrating the data obtained from the studies including regional geology, ore geology, fluid inclusion, and C–H–O–S–Pb isotope geochemistry, we conclude that the Wulong deposit is a decratonization gold deposit formed during lithospheric thinning associated with destruction of the North China Craton triggered by the subduction of the Paleo-Pacific Oceanic plate in the Early Cretaceous.

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