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Luoboling |
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Fujian, China |
| Main commodities:
Mo Cu
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Super Porphyry Cu and Au
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IOCG Deposits - 70 papers
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All papers now Open Access.
Available as Full Text for direct download or on request. |
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The Luoboling porphyry molybdenum deposit is located in the Zijinshan mining district, ~17 km north of Shanghang and 190 km WNW of Xiamen in Fujian Province, south-eastern China. It is ~2 km ENE of the main Zijinshan Au-Cu deposit.
Within the immediate Luoboling deposit area there are three main plutons: the Sifang granodiorite, the Luoboling granodiorite porphyry and the Zhongliao porphyritic biotite-granodiorite. The Cu–Mo orebodies of the deposit are hosted within the Luoboling granodiorite porphyry. The Luoboling granodiorite porphyry and the barren Zhongliao porphyritic biotite-granodiorite both intrude the barren Sifang granodiorite pluton. The Sifang granodiorite comprises 35 to 40% plagioclase, 15 to 20% quartz, 20 to 25% K feldspar, 10% hornblende and 10% biotite, with accessory zir-con, apatite, magnetite and titanite, and is a high-K calc-alkaline and metaluminous intrusion dated at 115 to 114 Ma (LA–ICP–MS zircon U-Pb) considered as the emplacement age of the granodiorite batholiths.
The Luoboling granodiorite porphyry and Zhongliao porphyritic biotite-granodiorite are exposed over an area of 0.5 km2 (Zhong et al., 2014). The Luoboling granodiorite porphyry contains 0.5 to 5 mm euhedral to subhedral phenocrysts and is composed of 10%orthoclase, 20% plagioclase, 5% biotite, 10% amphibole and 10% quartz, with ~45% matrix of similar minerals. This granodiorite porphyry has a weakly peraluminous character with an intrusive age of 103.2 ±1.0 Ma (Li and Jiang, 2015), whereas the Zhongliao porphyritic biotite-granodiorite has two ages 110 ±1.1 Ma and 95.9 ±0.8 Ma (LA– ICP–MS zircon U-Pb; Li and Jiang, 2015; Li, 2015). Unlike the Luoboling pluton, the Zhongliao porphyritic biotite-granodiorite consists of 15% biotite, 5% amphibole, 55% feldspar, 20 to 25% quartz and up to ~1% acicular magnetite. The geochemical characteristics of the Zhongliao porphyritic biotite-granodiorite are similar to the Luoboling ore-bearing intrusion with high Sr (391to 555 ppm), low Y (11.2 to 18.4 ppm) and high Sr/Y ratios (27.0 to 45.8; Li and Jiang, 2015).
Barren 96 to 99 Ma porphyritic quartz monzonite dykes also intruded the Sifang and Luoboling plutons (Li and Jiang, 2014; Li et al., 2016). These dykes are composed of 0.5 to 4 mm euhedral plagioclase, biotite and quartz megacrysts scattered through a fine-grained groundmass of plagioclase, orthoclase, quartz, and biotite. The quartz monzonite dykes have isotopic values similar to the coeval and nearby enriched lithospheric mantle-derived mafic and syenitic rocks (Li and Jiang, 2014; Li et al., 2016), indicating that the quartz monzonitic rocks were likely derived from partial melting of enriched mantle sources (Li et al., 2016).
The Luoboling granodiorite porphyry hosts the sulphide-bearing quartz veins or stockworks that comprise the orebody which is ~50 to 500 m thick with saddle-like or arcuate in shape. Apart for molybdenite, other sulphide minerals include pyrite, chalcopyrite and digenite with minor bornite, covellite and magnetite. Gangue minerals include K feldspar, biotite, sericite, quartz, anhydrite, alunite, and dickite, reflecting the potassic, phyllic and alunite-dickite alteration alteration zoning.
The potassic alteration zone is predominantly composed of quartz, biotite, K feldspar and minor albite, with associated chalcopyrite, magnetite and molybdenite. The phyllic alteration zone contains the main quartz-chalcopyrite-pyrite and anhydrite-chalcopyrite veins associated with an alteration assemblage of of chlorite, sericite, anhydrite and quartz. The alunite-dickite alteration zone contains kaolinite, dickite, alunite, pyrophyllite and minor sericite, with pyrite, bornite, digenite and covellite.
The Luoboling deposit has 'proved' reserves of 0.58 and 0.065 Mt of contained Cu and Mo respectively (Zhong et al., 2014). This deposit was discovered as a porphyry system in an outcrop. It is thought to be connected to a deeper-seated porphyry below the Zijinshan epithermal Cu-Au deposit (So et al., 1998; Zhang, 2013).
The most recent source geological information used to prepare this decription was dated: 2017.
This description is a summary from published sources, the chief of which are listed below.
© Copyright Porter GeoConsultancy Pty Ltd. Unauthorised copying, reproduction, storage or dissemination prohibited.
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Jiang, S.-H., Bagas, L. and Liang, Q.-L., 2015 - New insights into the petrogenesis of volcanic rocks in the Shanghang Basin in the Fujian Province, China: in J. of Asian Earth Sciences v.105, pp. 48-67.
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Li., B. and Jiang, S.-Y., 2017 - Genesis of the giant Zijinshan epithermal Cu-Au and Luoboling porphyry Cu-Mo deposits in the Zijinshan ore district, Fujian Province, SE China: A multi-isotope and trace element investigation: in Ore Geology Reviews v.88, pp. 753-767.
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Mao, J., Cheng, Y., Chen, M. and Pirajno, F., 2013 - Major types and time-space distribution of Mesozoic ore deposits in South China and their geodynamic settings: in Mineralium Deposita v.48, pp. 267-294.
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Pan, J.-Y., Ni, P., Chi, Z., Wang, W.-B., Zeng, W.-C. and Xue, K., 2019 - Alunite 40Ar/39Ar and Zircon U-Pb Constraints on the Magmatic-Hydrothermal History of the Zijinshan High-Sulfidation Epithermal Cu-Au Deposit and the Adjacent Luoboling Porphyry Cu-Mo Deposit, South China: Implications for Their Genetic Association: in Econ. Geol. v.114, pp. 667-695.
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Zhao, X.-Y., Zhong, H., Hu, R.-Z., Mao, W., Bai, Z.-J., Lan, T.-G. and Xue, K., 2021 - 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: in Econ. Geol. v.116, pp. 581-606. doi:10.5382/econgeo.4788.
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Zhong, J., Chen, Y.-J., Pirajno, F., Chen, J., Li, J., Qi, J.-P., and Li, N., 2014 - Geology, geochronology, fluid inclusion and H-O isotope geochemistry of the Luoboling Porphyry Cu-Mo deposit, Zijinshan Orefield, Fujian Province, China: in Ore Geology Reviews v.57, pp. 61-77.
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Porter GeoConsultancy Pty Ltd (PorterGeo) provides access to this database at no charge. It is largely based on scientific papers and reports in the public domain, and was current when the sources consulted were published. While PorterGeo endeavour to ensure the information was accurate at the time of compilation and subsequent updating, PorterGeo, its employees and servants: i). do not warrant, or make any representation regarding the use, or results of the use of the information contained herein as to its correctness, accuracy, currency, or otherwise; and ii). expressly disclaim all liability or responsibility to any person using the information or conclusions contained herein.
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