Cobalt zoning in microscopic pyrite from Kamoto, Republic of the Congo (Kinshasa)

Metallogenesis of the Nkana copper–cobalt South Orebody, Zambia

“…The genesis of such mineralization is interpreted to have taken place during diagenesis of the host sediments (Bartholomé et al, 1971(Bartholomé et al, , 1972Bartholomé, 1974;Dimanche, 1974;Sweeney et al, 1986;Unrug, 1988;Binda, 1989, 1994;Cailteux et al, 2005;Muchez et al, 2008). Barra et al (2004) and Barra and Broughton (unpublished data, in Selley et al, 2005) used ReOs isotopes to demonstrate the occurrence of an episode of diagenetic mineralization in the Zambian Copperbelt.…”

“…Studies concerning diagenetic processes in sedimentary rocks triggered the development of early, intermediate or late diagenetic models, suggesting precipitation of the sulphides during large-scale chemical reaction of the host rock and its porefluid with a metalliferous brine (e.g. Bartholomé et al, 1971Bartholomé et al, , 1972Bartholomé, 1974;Annels, 1984Annels, , 1989Unrug, 1988;Ngoyi and Dejonghe, 1995;Cailteux et al, 2005;Selley et al, 2005;Dewaele et al, 2006;Muchez et al, 2008). In these models the role of evaporites and evaporitic brines is usually highly emphasized.…”

Multiphase origin of the Cu–Co ore deposits in the western part of the Lufilian fold-and-thrust belt, Katanga (Democratic Republic of Congo)

“…The association of the cobalt mineralization and a major part of the copper mineralization with diagenetic minerals (dolomite) indicates that both precipitated during further diagenesis (Bartholomé, 1974;Bartholomé et al, 1971Bartholomé et al, , 1972Cailteux et al, 2005;Dimanche, 1974;Unrug, 1988). This generation of sulphides consists of a first phase of carrolite, bornite, digenite and chalcocite, associated with authigenic quartz.…”

“…Oosterbosch, 1951;Bartholomé, 1974;Bartholomé et al, 1971Bartholomé et al, , 1972Cailteux, 1994). Framboidal pyrite is characteristic for a synsedimentary to early diagenetic precipitation.…”

“…Nevertheless, a synsedimentary to very early diagenetic origin is still favoured by Okitaudji (1989Okitaudji ( , 1992Okitaudji ( , 2001 for the Cu-Co deposits of Katanga in the DRC. Bartholomé et al (1971Bartholomé et al ( , 1972 and Bartholomé (1974) proposed a diagenetic, pre-deformation timing for the Cu-Co mineralization at Kamoto at the western end of the Lufilian fold-and-thrust belt. In this model an early sulphide generation formed during deposition and early diagenesis of the host-rocks, followed by a second sulphide generation due to the interaction of the hostsediment and its pore water with a metal-bearing brine.…”