Climax-Type Porphyry Molybdenum Deposits

Ludington, Steve; Plumlee, Geoffrey S.

doi:10.3133/ofr20091215

Cited by 57 publications

(37 citation statements)

References 20 publications

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“…In contrast, in rift‐ or Climax‐type deposits, there are abundant coexisting saline (30–65 wt.%) and V‐type inclusions, and coexisting low‐ to moderate‐salinity L‐type inclusions (1–20 wt.%) and C‐type inclusions. Like the rift‐ or Climax‐type deposits, where phyllic and propylitic alteration are well developed (Ludington & Plumlee, ), the hydrothermal alteration at Gaogangshan is dominated by silicification–potassic alteration, followed by phyllic and propylitization, in addition to the carbonatization and fluoritization. The common presence of fluorite suggests an affinity for rift‐ or Climax‐type deposits.…”

Section: Discussionmentioning

confidence: 99%

Ore Genesis and Formation Age of the Gaogangshan Mo Deposit, Heilongjiang Province, NE China

et al. 2015

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The Gaogangshan Mo deposit, located in the northern part of the Lesser Xing'an Range (the eastern part of the Xing'an-Mongolia Orogenic Belt), is one of the newly discovered Mo deposits in northeast China. Ore bodies occur in the granite and are generally in vein and stockwork forms. Major metallic minerals in the ore include pyrite and molybdenite. The styles of mineralization are disseminated, veinlet-disseminated, and veinlet. The major types of wall-rock alteration are silicification-potassic alteration, phyllic alteration and propylitization. Fluid inclusion analyses indicate that the ore-forming fluid during the major mineralization stage is an H2O-NaCl-CO2 system, with wide homogenization temperature and salinity ranges. The abundant CO2-rich and coexisting halite-bearing fluid inclusion assemblages in the main stage of mineralization highlight the significance of intensive fluid boiling for porphyry Mo mineralization. Comprehensive study of the ore-forming conditions, geological features of the deposit, micro-thermometric analysis of fluid inclusions and comparison of the Gaogangshan deposit with other typical porphyry deposits leads to the conclusion that the deposit is a porphyry type. We obtained a weighted mean age of the molybdenite deposit at Gaogangshan of 250.7 ± 1.8 Ma. The isotopic dating results indicate that the Gaogangshan deposit was formed in the Permo-Triassic, which is the earliest Mo-only deposit in northeast China. The formation of the Gaogangshan Mo deposit may be related to the extension and break-up of the Songnen Block and Jiamusi Block in the Permo-Triassic.

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Section: Discussionmentioning

confidence: 99%

Ore Genesis and Formation Age of the Gaogangshan Mo Deposit, Heilongjiang Province, NE China

et al. 2015

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“…Similarly, while many economic Mo deposits are associated with arc-derived, calc-alkaline magmas (Westra and Keith, 1981;Whalen et al, 2001), the highest-grade Moporphyry deposits are associated with rift settings (e.g., Climax-type deposits; Ludington and Plumlee, 2009), and alkaline magmas from continental rifts show significant Mo enrichments (Audétat, 2010;Audétat et al, 2011). The source of Mo in these rift-related magmas is unclear; both the lithospheric mantle and the continental crust have been suggested as sources.…”

Section: Molybdenum Enrichments In Rift-related Magmasmentioning

confidence: 99%

Geochemistry of molybdenum in the continental crust

Greaney

Rudnick

Gaschnig

et al. 2018

Geochimica et Cosmochimica Acta

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The use of molybdenum as a quantitative paleo-atmosphere redox sensor is predicated on the assumption that Mo is hosted in sulfides in the upper continental crust (UCC). This assumption is tested here by determining the mineralogical hosts of Mo in typical Archean, Proterozoic, and Phanerozoic upper crustal igneous rocks, spanning a compositional range from basalt to granite. Common igneous sulfides such as pyrite and chalcopyrite contain very little Mo (commonly below detection limits of around 10 ng/g) and are not a significant crustal Mo host. By contrast, volcanic glass and Ti-bearing phases such as titanite, ilmenite, magnetite, and rutile contain significantly higher Mo concentrations (e.g., up to 40 µg/g in titanite), and can account for the whole-rock Mo budget in most rocks. However, mass balance between whole-rock and mineral data is not achieved in 4 out of 10 granites analyzed with in-situ methods, where Mo may be hosted in undetected trace molybdenite. Significant Mo depletion (i.e., UCC-normalized Mo/Ce < 1) occurs in nearly every granitic rock analyzed here, but not in oceanic basalts or their differentiates (Greaney et al., 2017; Jenner and O'Neill, 2012). On average, granites are missing $60% of their expected Mo contents. There are two possible reasons for this: (1) Mo partitions into an aqueous magmatic vapor/fluid phase that is expelled from cooling plutons, and/or (2) Mo is partitioned into titaniferous phases during partial melting and fractional crystallization of an evolving magma. The first scenario is likely given the high solubility of oxidized Mo. However, correlations between Mo/Ce and Nb/La in several plutonic suites suggest fractionating phases such as rutile or Fe-Ti oxides may sequester Mo in lower crustal rocks or in subducting slabs in arc settings.

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“…More extensive exposures of quartz-sericite-pyrite (QSP) alteration were identified to the north of the topaz exposure, and are expressed on the map as the "jarosite + sericite +/-gypsum" mineral mixture shown in cyan. Topaz occurs as an accessory mineral in the ore assemblages of many Climax-type porphyry molybdenum deposits (Ludington and Plumlee, 2009), and in fluorine-rich rhyolites and granites (Haapala, 1997).…”

Section: Commentsmentioning

confidence: 99%

Comparative mineral mapping in the Colorado Mineral Belt using AVIRIS and ASTER remote sensing data

Rockwell¹

2013

Scientific Investigations Map

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Climax-Type Porphyry Molybdenum Deposits

Cited by 57 publications

References 20 publications

Ore Genesis and Formation Age of the Gaogangshan Mo Deposit, Heilongjiang Province, NE China

Ore Genesis and Formation Age of the Gaogangshan Mo Deposit, Heilongjiang Province, NE China

Geochemistry of molybdenum in the continental crust

Comparative mineral mapping in the Colorado Mineral Belt using AVIRIS and ASTER remote sensing data

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