Review of the origin of breccias and their resource potential in the central Africa Copperbelt
Pascal Mambwe, Rudy Swennen, Jacques Cailteux, Mumba Chabu, Stijn Dewaele, Philippe Muchez
Abstract
The Katanga Supergroup, host of several world class Neoproterozoic sediment-hosted stratiform copper and cobalt deposits, is part of the Central Africa Copperbelt (CACB). The origin and classification of the breccia, which is one of the most characteristic features of the Katanga Supergroup, has been a matter of discussion since the 19th century. Different nomenclatures and various classifications have been used in the mining operations across the CACB. The difficulty to identify genetically related types of breccia creates some problems in regional correlations and comparisons. In addition, their origin is most relevant for the metallogenesis of the world-class copper and cobalt sediment-hosted deposits. This paper classifies the breccia according to their characteristics, reviews the mechanisms of brecciation, and thus addresses their origin, and highlights their potential in metal resources. The different types of breccias found in CACB include sedimentary breccia (gravity flow, sedimentary breccia stricto sensu), dissolution and collapse breccia, hyaloclastite breccia, hydraulic breccia and tectonic breccia (thrust-breccia and fault breccia). The spatial and chronological distribution of these breccias in the CACB follows the geodynamic history of the area starting from early Neoproterozoic rifting up to the Lufilian orogeny and post-Lufilian tectonism.