Petrographic, fluid inclusion and isotopic study of the Dikulushi Cu-Ag deposit, Katanga (DRC): implications for exploration
Haest, M.; Muchez, P.; Dewaele, S.; Boyce, A.J.; von Quadt, A.; Schneider, J. (2009). Petrographic, fluid inclusion and isotopic study of the Dikulushi Cu-Ag deposit, Katanga (DRC): implications for exploration. Mineralium Deposita 44(5): 505-522. https://dx.doi.org/10.1007/s00126-009-0230-x
In: Mineralium Deposita. Springer: New York. ISSN 0026-4598; e-ISSN 1432-1866, meer
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| Author keywords |
Dikulushi Cu-Ag deposit; Vein-type mineralisation; Copperbelt; Fluidinclusions; Stable and radiogenic isotopes; Kundelungu Plateau |
| Auteurs | | Top |
- Haest, M.
- Muchez, P., meer
- Dewaele, S., meer
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- Boyce, A.J.
- von Quadt, A.
- Schneider, J.
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| Abstract |
The Dikulushi Cu–Ag vein-type deposit is located on the Kundelungu Plateau, in the southeastern part of the Democratic Republic of Congo (D.R.C.). The Kundelungu Plateau is situated to the north of the Lufilian Arc that hosts the world-class stratiform Cu–Co deposits of the Central African Copperbelt. A combined petrographic, fluid inclusion and stable isotope study revealed that the mineralisation at Dikulushi developed during two spatially and temporally distinct mineralising episodes. An early Cu–Pb–Zn–Fe mineralisation took place during the Lufilian Orogeny in a zone of crosscutting EW- and NE-oriented faults and consists of a sequence of sulphides that precipitated from moderate-temperature, saline H2O–NaCl–CaCl2-rich fluids. These fluids interacted extensively with the country rocks. Sulphur was probably derived from thermochemical reduction of Neoproterozoic seawater sulphate. Undeformed, post-orogenic Cu–Ag mineralisation remobilised the upper part of the Cu–Pb–Zn–Fe mineralisation in an oxidising environment along reactivated and newly formed NE-oriented faults in the eastern part of the deposit. This mineralisation is dominated by massive Ag-rich chalcocite that precipitated from low-temperature H2O–NaCl–KCl fluids, generated by mixing of moderate- and low-saline fluids. The same evolution in mineralisation assemblages and types of mineralising fluids is observed in three other Cu deposits on the Kundelungu Plateau. Therefore, the recognition of two distinct types of (vein-type) mineralisation in the study area has a profound impact on the exploration in the Kundelungu Plateau region. The identification of a Cu–Ag type mineralisation at the surface could imply the presence of a Cu–Pb–Zn–Fe mineralisation at depth. |
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