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Contrôle lithostructural de la circulation des fluides minéralisateurs et piégeages des composants métalliques transportés dans l’espace transfrontalier du Kivu (Kalehe, Idjwi, Nya-Ngezie et Kamanyola)-Rwanda-Burundi

(2024)
Author
Promoter
Louis Nahimana, (UGent) , Damien Delvaux and Charles Nzolang
Organization
Abstract
The central part of the Karagwe-Ankole Belt (KAB) in the Great Lakes region of Central Africa is rich in various rare and strategic elements. The area north of Kalehe, Idjwi Island, Nya-Ngezie and Kamanyola in South Kivu province, eastern Democratic Republic of Congo (DRC), contains Nb, Ta, Sn and W mineralisation in pegmatites and quartz veins associated with leucogranite intrusions. Lithostratigraphic, geochronological, petrographic and petrogenetic, geochemical, structural and metallogenic studies were carried out to determine the lithostructural control and formation of Nb, Ta, Sn and W mineralisation in these regions. A lithostratigraphic correlation of the eastern part of the DRC, Rwanda and Burundi shows a continuity of KAB in this part of the DRC, which is made up of granitoids, metagabbros, metabasalts, volcanic rocks and metasediments. The latter are derived from felsic to intermediate magmatic protholiths and quartzite sedimentary protholiths. Partial melting of metasediments, tonalites and probably other lithologies is thought to be the source of the magma that produced the S-type granitoids found in the various geological formations defined in these regions. The latter were affected by ductile and brittle tectonics. These deformations played an essential role in the emplacement of Nb, Ta, Sn and W mineralisation, which is trapped in quartz veins and pegmatites that are mostly related with the schistosity. Quartz and pegmatites veins with various orientations are present in this region. A study of the palaeostresses responsible for setting up the fractures (joints and faults) in the study zones shows the presence of deformation events characteristic of the Pan-African (N-S compression) and the reactivation linked to the Rifting that affected the whole area (E-W extension). The mineralogy of the pegmatite vein systems is spatially zoned. The muscovites were analysed in each zone and used to calculate pegmatite fractionation trends using the Rayleigh fractionation model. Our model uses published partition coefficients (Kd) and measured K, Rb and Cs contents in the muscovite. Muscovites from consecutive pegmatite zones in the Bugarula and Kalehe pegmatite fields show a continuous fractionation trend, indicating a co-genetic magmatic evolution. As in other parts of KAB, particularly in Rwanda and Burundi, the Kalehe and Idjwi Island regions demonstrate the syngenetic link between pegmatites and leucogranites. The muscovites of the advanced and mineralised pegmatites show high concentrations of Nb, Ta and Sn. Variations in the alkaline element compositions of muscovites in these pegmatites provide a powerful tool for tracking Nb-Ta, Sn (and W) enrichment and potential mineralisation.

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MLA
Kalikone, Christian Buzera. Contrôle Lithostructural de La Circulation Des Fluides Minéralisateurs et Piégeages Des Composants Métalliques Transportés Dans l’espace  Transfrontalier Du Kivu (Kalehe, Idjwi, Nya-Ngezie et Kamanyola)-Rwanda-Burundi. Ecole doctorale. Faculté des Sciences, 2024.
APA
Kalikone, C. B. (2024). Contrôle lithostructural de la circulation des fluides minéralisateurs et piégeages des composants métalliques transportés dans l’espace  transfrontalier du Kivu (Kalehe, Idjwi, Nya-Ngezie et Kamanyola)-Rwanda-Burundi. Ecole doctorale. Faculté des Sciences, Bujumbura, Burundi.
Chicago author-date
Kalikone, Christian Buzera. 2024. “Contrôle Lithostructural de La Circulation Des Fluides Minéralisateurs et Piégeages Des Composants Métalliques Transportés Dans l’espace  Transfrontalier Du Kivu (Kalehe, Idjwi, Nya-Ngezie et Kamanyola)-Rwanda-Burundi.” Bujumbura, Burundi: Ecole doctorale. Faculté des Sciences.
Chicago author-date (all authors)
Kalikone, Christian Buzera. 2024. “Contrôle Lithostructural de La Circulation Des Fluides Minéralisateurs et Piégeages Des Composants Métalliques Transportés Dans l’espace  Transfrontalier Du Kivu (Kalehe, Idjwi, Nya-Ngezie et Kamanyola)-Rwanda-Burundi.” Bujumbura, Burundi: Ecole doctorale. Faculté des Sciences.
Vancouver
1.
Kalikone CB. Contrôle lithostructural de la circulation des fluides minéralisateurs et piégeages des composants métalliques transportés dans l’espace  transfrontalier du Kivu (Kalehe, Idjwi, Nya-Ngezie et Kamanyola)-Rwanda-Burundi. [Bujumbura, Burundi]: Ecole doctorale. Faculté des Sciences; 2024.
IEEE
[1]
C. B. Kalikone, “Contrôle lithostructural de la circulation des fluides minéralisateurs et piégeages des composants métalliques transportés dans l’espace  transfrontalier du Kivu (Kalehe, Idjwi, Nya-Ngezie et Kamanyola)-Rwanda-Burundi,” Ecole doctorale. Faculté des Sciences, Bujumbura, Burundi, 2024.
@phdthesis{01HSV2MXZYVZ9RWTP731GYY2S1,
  abstract     = {{The central part of the Karagwe-Ankole Belt (KAB) in the Great Lakes region of Central Africa is rich in various rare and strategic elements. The area north of Kalehe, Idjwi Island, Nya-Ngezie and Kamanyola in South Kivu province, eastern Democratic Republic of Congo (DRC), contains Nb, Ta, Sn and W mineralisation in pegmatites and quartz veins associated with leucogranite intrusions. Lithostratigraphic, geochronological, petrographic and petrogenetic, 
geochemical, structural and metallogenic studies were carried out to determine the lithostructural control and formation of Nb, Ta, Sn and W mineralisation in these regions. A lithostratigraphic correlation of the eastern part of the DRC, Rwanda and Burundi shows a continuity of KAB in this part of the DRC, which is made up of granitoids, metagabbros, metabasalts, volcanic rocks and metasediments. The latter are derived from felsic to intermediate magmatic protholiths and quartzite sedimentary protholiths. Partial melting of metasediments, tonalites and probably other lithologies is thought to be the source of the magma that produced the S-type granitoids found in the various geological formations defined in these regions. The latter were affected by ductile and brittle tectonics. These deformations played an essential role in the emplacement of Nb, Ta, Sn and W mineralisation, which is trapped in quartz veins and pegmatites that are mostly related with the schistosity. Quartz and pegmatites veins 
with various orientations are present in this region. A study of the palaeostresses responsible for setting up the fractures (joints and faults) in the study zones shows the presence of deformation events characteristic of the Pan-African (N-S compression) and the reactivation linked to the Rifting that affected the whole area (E-W extension). The mineralogy of the pegmatite vein systems is spatially zoned. The muscovites were analysed in each zone and used to calculate pegmatite fractionation trends using the Rayleigh fractionation model. Our model uses published partition coefficients (Kd) and measured K, Rb and Cs contents in the muscovite. 
Muscovites from consecutive pegmatite zones in the Bugarula and Kalehe pegmatite fields show a continuous fractionation trend, indicating a co-genetic magmatic evolution. As in other parts of KAB, particularly in Rwanda and Burundi, the Kalehe and Idjwi Island regions demonstrate the syngenetic link between pegmatites and leucogranites. The muscovites of the advanced and mineralised pegmatites show high concentrations of Nb, Ta and Sn. Variations in the alkaline element compositions of muscovites in these pegmatites provide a powerful tool for tracking Nb-Ta, Sn (and W) enrichment and potential mineralisation.}},
  author       = {{Kalikone, Christian Buzera}},
  language     = {{fre}},
  pages        = {{XII, 269}},
  publisher    = {{Ecole doctorale. Faculté des Sciences}},
  title        = {{Contrôle lithostructural de la circulation des fluides minéralisateurs et piégeages des composants métalliques transportés dans l’espace  transfrontalier du Kivu (Kalehe, Idjwi, Nya-Ngezie et Kamanyola)-Rwanda-Burundi}},
  year         = {{2024}},
}