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Feng C.,Chinese Academy of Geological Sciences | Zhao Z.,Chinese Academy of Geological Sciences | Zeng Z.,South Jiangxi Geological Survey Party of JBEDGMR
Ore Geology Reviews | Year: 2015

The large Huamei'ao tungsten deposit, with total WO3 reserves of 67,400tons at an average grade of 1.334% WO3, is located in the convergent zone of the eastern Nanling E-W-trending tectono-magmatic belt and the western Wuyishan NNE-SSW-trending tectono-magmatic belt in southern Jiangxi Province, China. The tungsten mineralization in this deposit is mainly found in quartz-wolframite veins, with most orebodies distributed at the outer contact zone between concealed Late Jurassic granitic stocks and Sinian weakly metamorphosed sandstones and phyllites. Zircons collected from medium- to fine-grained biotite granite in a diamond drill hole at a sea level of ca. -10m yield a crystallization age of 159.9 (±1.2) Ma through laser ablation-multicollector-inductively coupled plasma-mass spectrometry (LA-MC-ICP-MS) U-Pb dating. Molybdenite and muscovite that were both separated from quartz-wolframite veins yield a Re-Os isochron age of 158.5 (±3.3) Ma and an 40Ar-39Ar weighted plateau age of 157.9 (±1.1) Ma, respectively. These dates, obtained via three independent geochronological techniques, constrain the ore-forming age of the Huamei'ao deposit and link the genesis of the ore and the underlying granite. Analyses of available high-precision zircon U-Pb, molybdenite Re-Os and muscovite 40Ar-39Ar radiometric ages of major W-Sn deposits in southern Jiangxi Province indicate that there is no significant time interval between W-Sn mineralization and its intimately associated parent granite emplacement (interval of 0-6Ma). These deposits formed over three intervals during the Mesozoic (240-210, 170-150, and 130-90Ma), with large-scale W-Sn mineralization occurring mainly between 160 and 150Ma. The majority of W-Sn deposits in this region are located in southern Jiangxi and southern Hunan provinces. © 2014 Elsevier B.V.

Feng C.,Chinese Academy of Geological Sciences | Zeng Z.,South Jiangxi Geological Survey Party of JBEDGMR | Zhang D.,Chinese Academy of Geological Sciences | Li D.,Chinese Academy of Geological Sciences | She H.,Chinese Academy of Geological Sciences
Ore Geology Reviews | Year: 2011

The southern Jiangxi Province is a major part of the Nanling W-Sn metallogenic province of southern China, where all W-Sn ore deposits are temporally and spatially related to Mesozoic granitic intrusions. The Tianmenshan-Hongtaoling orefield is a recently explored territory endowed by several styles of W-Sn mineralization. The orefield comprises three composite granitic plutons: Tianmenshan, Hongtaoling and Zhangtiantang associated with several tens of W-Sn-polymetallic ore deposits (Maoping, Baxiannao, Niuling, Zhangdou, Yaolanzhai and others) along their contacts. In this study, four new SHRIMP zircon U-Pb ages were determined for three composite granitic plutons, and 33 molybdenite samples from five W-Sn deposits were analysed by ICP-MS Re-Os isotopic method. SHRIMP zircon U-Pb ages for both medium to coarse-gained biotite granite and porphyritic biotite monzogranite from the Tianmenshan composite pluton are 157.2 ± 2.2. Ma and 151.8 ± 2.9. Ma, respectively. Molybdenite Re-Os isochron ages for the related Baxiannao fracture-controlled tungsten deposits are 157.9 ± 1.5. Ma. Maoping greisens-type tungsten deposits were emplaced at 155.3 ± 2.8. Ma and the Maoping wolframite-quartz veins at 150.2 ± 2.8. Ma, respectively. The SHRIMP U-Pb age of zircons from the Hongtaoling biotite granite is 151.4 ± 3.1. Ma whereas the molybdenite Re-Os isochron ages of the genetically related Niuling endocontact tungsten quartz veins and Zhangdou exocontact tungsten quartz veins are 154.9 ± 4.1 to 154.6 ± 9.7. Ma and 149.1 ± 7.1. Ma, respectively. The SHRIMP zircon U-Pb age of the Zhangtiantang fine-grained muscovite granite is 156.9 ± 1.7. Ma, whereas the molybdenite Re-Os isochron age for the related Yaolanzhai greisens-type tungsten deposit is 155.8 ± 2.8. Ma. These new age data, combined with those available from the literature, indicate that the ages of W-Sn ores and related granites are Late Jurassic with a peak at 150 to 160. Ma, which corresponds to the widespread Mesozoic metallogenic event in southern China. Molybdenites from this group of tungsten deposits have quite low Re contents (29.1 to 2608. ppb), suggesting continental crustal provenance of the ore metals. © 2011 Elsevier B.V.

Feng C.,Institute of Mineral Resources | Zhang D.,Institute of Mineral Resources | Zeng Z.,South Jiangxi Geological Survey Party of JBEDGMR | Wang S.,China Coal Technology and Engineering Co.
Acta Geologica Sinica | Year: 2012

Previous studies have obtained some petrogenetic and metallogenic chronological data with SHRIMP (sensitive high-resolution ion microprobe) zircon U-Pb, zircon LA-ICPMS (laser-ablation-inductively coupled plasma mass spectroscopy) U-Pb, molybdenite Re-Os isochron and muscovite Ar-Ar methods in southern Jiangxi Province and its adjacent areas. Based on these, the purpose of this paper is to study the petrogenetic and metallogenic ages and their time gap for different genetic types of W-Sn deposits, and thus to research their numerous episodes, zonal arrangement and their geodynamic background. The result shows that the large-scale W-Sn mineralization in southern Jiangxi Province occurred in the middle to late Jurassic (170-150 Ma), the skarn W-Sn-polymetallic deposits formed much earlier (170-161 Ma), and all of the wolframite - quartz vein type, greisen type, altered granite type and fractured zone type tungsten deposits formed in the late Jurassic (160-150 Ma). In one ore field or ore district, greisen type tungsten deposits formed earlier than quartz vein type ones hosted in the endo- or exo-contact zone; and quartz vein type hosted in the endocontact zone formed earlier than that of exocontact zone. There is no significant time difference between tungsten-tin mineralization and its intimately associated parent granite emplacement (1-6 Ma). They all formed in the same rock-forming and ore-forming system and under the same geodynamic setting. Regionally, rock-forming and ore-forming processes of the W-Sn deposits in the Nanling region (include southern Jiangxi Province, southern Hunan Province, northern Guangdong Province and eastern Guangxi Zhuang Autonomous Region) exhibit numerous episodes. The mineralization in the Nanling region mainly occurred at (240-210) Ma, (170-150) Ma and (130-90) Ma. The tungsten-tin deposits in this region are centered by the largest scale in southern Jiangxi Province and southern Hunan Province, and become small in the east, west, south and north directions. This displays a zonal arrangement and temporal and spatial distribution regularity. Integrated with the latest research results, it is concluded that the W-Sn mineralization in southern Jiangxi Province and its adjacent areas corresponds to the second large-scale mineralization in South China. The Indosinian W-Sn mineralization formed under the extensional tectonic regime between collisional compressional stages, while the Yanshanian large-scale petrogenetic and metallogenic processes occurred in the Jurassic intraplate extensional geodynamic setting of lithosphere extension.

Feng C.Y.,Chinese Academy of Geological Sciences | Wang S.,China Coal Technology and Engineering Co. | Zeng Z.L.,South Jiangxi Geological Survey Party of JBEDGMR | Zhang D.Q.,Chinese Academy of Geological Sciences | And 2 more authors.
Acta Petrologica Sinica | Year: 2012

Baxiannao is a typical mineralized fractured zone-type W-Sn polymetallic deposit which was discovered recently. Based on detailed petrographic observations and microthermometric studies of fluid inclusion, hydrogen and oxygen isotopes and radiometric dating, this paper studied the origin and evolution of the ore-forming fluid, ages of tungsten mineralization and petrogenesis and tectonic environment of this deposit. The results show that the fluid inclusions are mainly of H2O-NaCl type with minor CO 2 type. The homogenization temperature peaks of low (150 ∼ \1Q°C , 200 ∼ 220T1 ) , medium ( 250 ∼ 21Q°C ) and high ( 290 ∼ 310T1) indicate multistage fluid activities. The ore-forming fluid is a type of low-salinity, low-density H2O-CO2-NaCl system. The δD values of fluids from fluid inclusions in quartz vary from-78%e to -65%e, δ18:OH2O values of quartz from the ore change from 4.33%e to 6.44%e, suggesting the ore-forming fluid was derived mainly from magmatic water and was mixed by meteoric water. The dating of zircon from biotite granite determined by SHRIMP yields an age of 157.2 ± 2.2Ma. Re-Os isotopic dating of molybdenite from the Baxiannao fractured zone-type tungsten deposit by ICP-MS yield an isochron age of 157.9 ± 1.5Ma, which is consistent with diagenetic age of biotite granite. Combined with those available from the literature, it can be concluded that tungsten mineralization occurred at the same geodynamic background that is Jurassic intraplate extensional environment during the large-scale extension period of lithosphere in southern China.

Zhang D.-Q.,Chinese Academy of Geological Sciences | Feng C.-Y.,Chinese Academy of Geological Sciences | Li D.-X.,Chinese Academy of Geological Sciences | Chen Y.-C.,Chinese Academy of Geological Sciences | Zeng Z.-L.,South Jiangxi Geological Survey Party of JBEDGMR
Jilin Daxue Xuebao (Diqiu Kexue Ban)/Journal of Jilin University (Earth Science Edition) | Year: 2012

Based on the analysis of fluid inclusions (including the laser Raman spectroscopy), hydrogen and oxygen isotope in the quartz grains formed in different metallogenic stages, ore-forming physical-chemical condition and ore genesis of the Taoxikeng tungsten and tin deposit in southern Jiangxi Province have been summarized. Such five types of fluid inclusions are identified as gas, liquid, liquid-rich two-phase, gas-rich two-phase and three-phase with liquid carbon dioxide. According to characteristics of ore-forming fluid, two metallogenic stages are indicated: the early silicate-oxide stage (310-390°C) and late oxide-sulfide stage (180-270°C), respectively. Laser Raman spectroscopy of seven inclusions shows that the gas-phase in the inclusions belongs to the NaCl-H 2O series rich in CO 2, and the liquid-phase to the NaCl-H 2O series poor in CO 2. The δD values in inclusions from five samples change from -64‰ to -79‰, and δ 18O water from 5.51‰ to 6.53‰, which indicates that the ore-forming fluid was derived from the deep magmatic water. According to data mentioned above and from other research in this area, it can be concluded that the Taoxikeng deposit belongs to the magmatic hydrothermal tungsten and tin deposit associated with the S-type granite.

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