Rock magnetic investigation and its geological significance for vein-type uranium deposits in southern China

2017 ◽  
Vol 18 (4) ◽  
pp. 1333-1349
Author(s):  
Kunpeng Ge ◽  
Qingsong Liu ◽  
Juzhi Deng ◽  
David Nobes ◽  
Yang Wang ◽  
...  
Keyword(s):  
Southern China ◽  
Uranium Deposits ◽  
Geological Significance ◽  
Vein Type ◽  
Magnetic Investigation

scholarly journals Uraninite, Coffinite and Ningyoite from Vein-Type Uranium Deposits of the Bohemian Massif (Central European Variscan Belt)

Minerals ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 123 ◽  
Author(s):  
Miloš René ◽  
Zdeněk Dolníček ◽  
Jiří Sejkora ◽  
Pavel Škácha ◽  
Vladimír Šrein
Keyword(s):  
Chemical Composition ◽  
Electron Microprobe ◽  
Bohemian Massif ◽  
Uranium Deposit ◽  
Ore Deposits ◽  
Metamorphic Rocks ◽  
Uranium Deposits ◽  
Massif Central ◽  
Vein Type ◽  
Ore District

Uraninite-coffinite vein-type mineralisation with significant predominance of uraninite over coffinite occurs in the Příbram, Jáchymov and Horní Slavkov ore districts and the Potůčky, Zálesí and Předbořice uranium deposits. These uranium deposits are hosted by faults that are mostly developed in low- to high-grade metamorphic rocks of the basement of the Bohemian Massif. Textural features and the chemical composition of uraninite, coffinite and ningyoite were studied using an electron microprobe. Collomorphic uraninite was the only primary uranium mineral in all deposits studied. The uraninites contained variable and elevated concentrations of PbO (1.5 wt %–5.4 wt %), CaO (0.7 wt %–8.3 wt %), and SiO2 (up to 10.0 wt %), whereas the contents of Th, Zr, REE and Y were usually below the detection limits of the electron microprobe. Coffinite usually forms by gradual coffinitization of uraninite in ore deposits and the concentration of CaO was lower than that in uraninites, varying from 0.6 wt % to 6.5 wt %. Coffinite from the Jáchymov ore district was partly enriched in Zr (up to 3.3 wt % ZrO2) and Y (up to 5.5 wt % Y2O3), and from the Potůčky uranium deposit, was distinctly enriched in P (up to 8.8 wt % P2O5), occurring in association with ningyoite. The chemical composition of ningyoite was similar to that from type locality; however, ningyoite from Potůčky was distinctly enriched in REE, containing up to 22.3 wt % REE2O3.

scholarly journals Uranium-bearing metasediment and granite in the Tasermiut area, South Greenland

1981 ◽  
Vol 105 ◽  
pp. 47-51
Author(s):  
B.L Nielsen ◽  
T Tukiainen
Keyword(s):  
Stream Sediments ◽  
Uranium Deposits ◽  
The South ◽  
Planning Stage ◽  
Preliminary Results ◽  
Bay Area ◽  
Vein Type ◽  
Uranium Exploration ◽  
Stream Waters

Regional exploration for uranium was carried out in South Greenland in 1979 and 1980. From the planning stage the area between the fjords Tasermiut and Søndre Sermilik (fig. 16) was considered a favourable target beeause uranium deposits from geological environments of similar age, strueture and lithology are known, e.g. the Makkovik Bay area in Labrador (Gandhi et al., 1969; McMillan, 1976). The deposits sought were mainly pegmatitic or vein type deposits related to a Proterozoie unconformity (Nielsen, 1980). During the South Greenland uranium exploration project the area was covered in 1979 by a regional reconnaissance gamma-spectrometric survey and by drainage geochemistry (stream sediments and stream waters). Several areas of anomalous radioactivity were recordcd (Armour-Brown et al.) 1980), and an the basis af this and short field visits in 1979 ir was decided to undertake a more systematic follow-up in 1980. The preliminary results af this work are reported below.

scholarly journals Vein-type uranium deposits

1975 ◽  
Author(s):  
R. Rich ◽  
H. Holland ◽  
U. Petersen
Keyword(s):  
Uranium Deposits ◽  
Vein Type

scholarly journals Influences of Hydraulic Fracturing on Fluid Flow and Mineralization at the Vein-Type Tungsten Deposits in Southern China

Geofluids ◽  
2017 ◽  
Vol 2017 ◽  
pp. 1-11 ◽  
Author(s):  
Xiangchong Liu ◽  
Huilin Xing ◽  
Dehui Zhang
Keyword(s):  
Fluid Flow ◽  
Pressure Drop ◽  
Hydraulic Fracturing ◽  
Numerical Experiments ◽  
Southern China ◽  
Fluid Pressure ◽  
Nanling Range ◽  
Fracturing Process ◽  
Vein Type ◽  
Tungsten Deposits

Wolframite is the main ore mineral at the vein-type tungsten deposits in the Nanling Range, which is a world-class tungsten province. It is disputed how wolframite is precipitated at these deposits and no one has yet studied the links of the mechanical processes to fluid flow and mineralization. Finite element-based numerical experiments are used to investigate the influences of a hydraulic fracturing process on fluid flow and solubility of CO2and quartz. The fluids are aqueous NaCl solutions and fluid pressure is the only variable controlling solubility of CO2and quartz in the numerical experiments. Significant fluctuations of fluid pressure and high-velocity hydrothermal pulse are found once rock is fractured by high-pressure fluids. The fluid pressure drop induced by hydraulic fracturing could cause a 9% decrease of quartz solubility. This amount of quartz deposition may not cause a significant decrease in rock permeability. The fluid pressure decrease after hydraulic fracturing also reduces solubility of CO2by 36% and increases pH. Because an increase in pH would cause a major decrease in solubility of tungsten, the fluid pressure drop accompanying a hydraulic fracturing process facilitates wolframite precipitation. Our numerical experiments provide insight into the mechanisms precipitating wolframite at the tungsten deposits in the Nanling Range as well as other metals whose solubility is strongly dependent on pH.

scholarly journals Source Analysis of Silicon and Uranium in uranium-rich shale in the Xiuwu Basin, Southern China

2019 ◽  
Vol 11 (1) ◽  
pp. 89-100
Author(s):  
Zhuo Li ◽  
Kun Zhang ◽  
Yan Song ◽  
Xiaoxue Liu ◽  
Zhenxue Jiang ◽  
...  
Keyword(s):  
Lower Cambrian ◽  
Southern China ◽  
Isotopic Analysis ◽  
Hydrothermal Activity ◽  
Hydrothermal Fluids ◽  
Source Analysis ◽  
Uranium Deposits ◽  
Uranium Enrichment ◽  
Element Analysis ◽  
Oxygen Isotopic

Abstract Uranium deposits are crucial resources for the development of the nuclear energy. Among known sources of uranium, the uranium-rich shales have recently obtained significance. In this paper, the Lower Cambrian Wangyinpu Formation shale in the Xiuwu Basin, southern China, has been studied using a combination of techniques including element analysis (Al, Fe, and Mn), δ30Si silicon isotopic analysis, δ18O oxygen isotopic analysis, study of core samples. It has been observed that significant hydrothermal activity occurred in the Xiuwu Basin during the Early Cambrian period. The results show that 20%–40% of the silicon in most of the sections of the Lower Cambrian Wangyinpu Formation were inherited from the hydrothermal fluids, with temperatures ranging between 75∘C and 102∘C. It is concluded that more than 90% of the uranium in most of the sections of the Lower Cambrian Wangyinpu shale was derived from submarine hydrothermal fluids, while less than 10% from the terrigenous detritus. The enrichment of uranium in the basin was observed in the Middle-Upper part of the Wangyinpu Formation and the geological resources estimated to a tune of ~4.9×103 t. In this paper, we proposed a model for silicon and uranium enrichment in the Lower Cambrian shale controlled by hydrothermal activity in the Xiuwu Basin. This model also provides a scientific rationale for uranium further exploration and exploitation of the uranium resource.

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