Lithostratigraphy of the Katangan supergroup in the Kalindi-Kipushi area at the DRC-Zambia border and its relationship to lithostratigraphic successions in other portions of the central African copperbelt

Abstract

This study describes the lithostratigraphy of the Katangan Supergroup from the Kansuki Formation of the Roan Group to the Kanianga Formation of the Kundelungu Group in the Southern Congolese Copperbelt (CCB) in the area south of the Kipushi mine. The study utilises information from diamond drill holes as well as information on the lateral extent of lithostratigraphic units from a new map of the area constructed from both geophysical and geochemical data. A lithofacies analysis approach is used to better understand depositional environments and controls on sedimentation. Facies variability and unconformities in the study area are related to active rifting and eustatic controls during deposition of the Mwashya and Muombe subgroups and a combination of thermal subsidence, salt withdrawal, and global eustatic controls during deposition of the Bunkeya and Gombela subgroups. Comparisons of the study area with areas to the north suggest they were separated by a structural high present from at least the time of deposition of the upper Mwashya Subgroup. The study area appears to exhibit deeper water facies than those of the comparable sequence present in the Zambian Copperbelt.