Genesis of the vein-type tungsten mineralization at Nyakabingo (Rwanda) in the Karagwe-Ankole belt, Central Africa

被引:43
|
作者
Dewaele, S. [1 ]
De Clercq, F. [2 ]
Hulsbosch, N. [2 ]
Piessens, K. [3 ]
Boyce, A. [4 ]
Burgess, R. [5 ]
Muchez, Ph. [2 ]
机构
[1] Royal Museum Cent Africa, Dept Geol & Mineral, Leuvensesteenweg 13, B-3080 Tervuren, Belgium
[2] Katholieke Univ Leuven, Dept Earth & Environm Sci, Geodynam & Geofluids Res Grp, Celestijnenlaan 200E, B-3001 Louvain, Belgium
[3] Royal Belgian Inst Nat Sci, Geol Survey Belgium, Jenner St 13, B-1000 Brussels, Belgium
[4] Scottish Univ Environm Res Ctr, Rankine Ave, E Kilbride G75 0QF, Lanark, Scotland
[5] Univ Manchester, Sch Earth Atmospher & Environm Sci, Oxford Rd, Manchester M13 9PL, Lancs, England
关键词
Fluid flow; Karagwe-Ankole belt; Neoproterozoic; Rwanda; Tungsten mineralization; ARDENNE SLATE BELT; CORNUBIAN ORE FIELD; W-SN DEPOSIT; FLUID INCLUSION; STABLE-ISOTOPE; QUARTZ VEINS; KIBARAN BELT; SULFIDE MINERALIZATION; AGE-DETERMINATIONS; SOUTHWEST ENGLAND;
D O I
10.1007/s00126-015-0608-x
中图分类号
P3 [地球物理学]; P59 [地球化学];
学科分类号
0708 ; 070902 ;
摘要
The vein-type tungsten deposit at Nyakabingo in the central Tungsten belt of Rwanda is located in the eastern flank of the complex Bumbogo anticlinal structure. The host rock is composed of alternating sequences of sandstones, quartzites, and black pyritiferous metapelitic rocks. Two types of W-mineralized quartz veins have been observed: bedding-parallel and quartz veins that are at high angle to the bedding, which are termed crosscutting veins. Both vein types have been interpreted to have been formed in a late stage of a compressional deformation event. Both vein types are associated with small alteration zones, comprising silicification, tourmalinization, and muscovitization. Dating of muscovite crystals at the border of the veins resulted in a maximum age of 992.4 +/- 1.5 Ma. This age is within error similar to the ages obtained for the specialized G4 granites (i.e., 986 +/- 10 Ma). The W-bearing minerals formed during two different phases. The first phase is characterized by scheelite and massive wolframite, while the second phase is formed by ferberite pseudomorphs after scheelite. These minerals occur late in the evolution of the massive quartz veins, sometimes even in fractures that crosscut the veins. The ore minerals precipitated from a H2O-CO2-CH4-N-2-NaCl-(KCl) fluid with low to moderate salinity (0.6-13.8 eq. wt% NaCl), and minimal trapping temperatures between 247 and 344 A degrees C. The quartz veins have been crosscut by sulfide-rich veins. Based on the similar setting, mineralogy, stable isotope, and fluid composition, it is considered that both types of W-mineralized quartz veins formed during the same mineralizing event. Given the overlap in age between the G4 granites and the mineralized quartz veins, and the typical association of the W deposits in Rwanda, but also worldwide, with granite intrusions, W originated from the geochemically specialized G4 granites. Intense water-rock interaction and mixing with metamorphic fluids largely overprinted the original magmatic-hydrothermal signature.
引用
收藏
页码:283 / 307
页数:25
相关论文
共 46 条
  • [1] Genesis of the vein-type tungsten mineralization at Nyakabingo (Rwanda) in the Karagwe–Ankole belt, Central Africa
    S. Dewaele
    F. De Clercq
    N. Hulsbosch
    K. Piessens
    A. Boyce
    R. Burgess
    Ph. Muchez
    [J]. Mineralium Deposita, 2016, 51 : 283 - 307
  • [2] Vein-type tungsten deposits in Rwanda, Rutsiro area of the Karagwe-Ankole Belt, Central Africa
    Tumukunde, Thomas d'Aquin
    Piestrzynski, Adam
    [J]. ORE GEOLOGY REVIEWS, 2018, 102 : 505 - 518
  • [3] Magmatic-Hydrothermal Origin for Tungsten in the Quartz Vein Deposits of the Karagwe-Ankole Belt (Rwanda)
    Hulsbosch, Niels
    Muchez, Philippe
    Boiron, Marie-Christine
    Dewaele, Stijn
    [J]. MINERAL RESOURCES IN A SUSTAINABLE WORLD, VOLS 1-5, 2015, : 765 - 768
  • [4] Metamorphic and metasomatic evolution of the Western Domain of the Karagwe-Ankole Belt (Central Africa)
    Van Daele, Johanna
    Hulsbosch, Niels
    Dewaele, Stijn
    Muchez, Philippe
    [J]. JOURNAL OF AFRICAN EARTH SCIENCES, 2020, 165
  • [5] Late orogenic gold mineralization in the western domain of the Karagwe-Ankole Belt (Central Africa): Auriferous quartz veins from the Byumba deposit (Rwanda)
    Wouters, Sander
    Hulsbosch, Niels
    Kaskes, Pim
    Claeys, Philippe
    Dewaele, Stijn
    Melcher, Frank
    Onuk, Peter
    Muchez, Philippe
    [J]. ORE GEOLOGY REVIEWS, 2020, 125
  • [6] Mineralogical characterization of cassiterite concentrates from quartz vein and pegmatite mineralization of the Karagwe-Ankole and Kibara Belts, Central Africa
    Dewaele, Stijn
    Goethals, Herman
    Thys, Tom
    [J]. GEOLOGICA BELGICA, 2013, 16 (1-2): : 66 - 75
  • [7] Characterisation and geodynamic setting of the 1 Ga granitoids of the Karagwe-Ankole belt (KAB), Rwanda
    De Clercq, S.
    Chew, D.
    O'Sullivan, G.
    De Putter, T.
    De Grave, J.
    Dewaele, S.
    [J]. PRECAMBRIAN RESEARCH, 2021, 356
  • [8] Granitic rocks from Rwanda: Vital clues to the tectonic evolution of the Karagwe-Ankole Belt
    Nambaje, Claude
    Satish-Kumar, M.
    Williams, Ian S.
    Takahashi, Toshiro
    Sajeev, K.
    [J]. LITHOS, 2021, 404
  • [9] Gold mineralization in the Mesoproterozoic Karagwe-Ankole belt (Byumba, Rwanda): new insights from petrography and trace element mapping
    Wouters, Sander
    Muchez, Philippe
    Dewaele, Stijn
    Kaskes, Pim
    Claeys, Philippe
    [J]. LIFE WITH ORE DEPOSITS ON EARTH, PROCEEDINGS OF THE 15TH SGA BIENNIAL MEETING, 2019, VOLS 1-4, 2019, : 659 - 662
  • [10] Fluid fractionation of tungsten during granite-pegmatite differentiation and the metal source of peribatholitic W quartz veins: Evidence from the Karagwe-Ankole Belt (Rwanda)
    Hulsbosch, Niels
    Boiron, Marie-Christine
    Dewaele, Stijn
    Muchez, Philippe
    [J]. GEOCHIMICA ET COSMOCHIMICA ACTA, 2016, 175 : 299 - 318