The nature of early basinal fluids in the Zambian Copperbelt: A case study from the Chambishi deposit

Evolution of Cu–Co mineralizing fluids at Nkana Mine, Central African Copperbelt, Zambia

“…Greyling (2009) proposed the early orogenic fluid inclusions were trapped near hydrostatic conditions at a maximum temperature and pressure of 260°C and 800 bar, which corresponds to a depth of 8 km at a hydrothermal gradient of 30°C/100 bar. A similar temperature and pressure was proposed by Greyling et al (2005) for early orogenic fluids at Chambishi, based on the crossing of the isochores of low saline aqueous inclusions with the isochore of CH 4 in fluid inclusion planes. However, the co-genetic relationship between these fluid inclusion planes and the exact timing is not demonstrated.…”

“…A five point Re-Os isochron with analyses of disseminated and vein-type sulphides of the Nkana, Chibulumba and Nchanga ore deposits yielded an age of 583 ± 24 Ma (Barra et al, 2004). This age corresponds to the onset of metamorphism and the orogeny (Rainaud et al, 2005), and thus likely represents the deformation phase related to the layer parallel phase or early orogenic mineralization phase as defined by Greyling et al (2005) in the Zambian Copperbelt.…”

“…Garlick, 1961Garlick, , 1964, the distinction between the different phases in geochemical studies has only recently been made in the Democratic Republic of Congo (DRC; El Desouky et al, 2009a, accepted for publication) and not in Zambia. Greyling et al (2005) distinguished different phases in their detailed microthermometric study of fluid inclusions in gangue minerals from a mineralized, lateral secretion bedding parallel quartz vein at Chambishi. The second major, late burial to syn-orogenic mineralization phase likely consists of several subphases (El Desouky et al, 2009a).…”

Metallogenesis of the Nkana copper–cobalt South Orebody, Zambia

“…However, the large error (62 Ma) does not exclude a late Roan to early Nguba age. Also Greyling et al (2005) indicated that lateral secretion quartz veins at Chambishi, which immediately post-date stratiform copper mineralization, had a diagenetic origin.…”

Geochronology of the Nchanga Granite, and constraints on the maximum age of the Katanga Supergroup, Zambian Copperbelt

“…Rocks of the Katanga Supergroup were deformed and metamorphosed during the Lufilian (%600-512 Ma) Orogeny (Cosi et al, 1992;Porada and Berhorst, 2000;Rainaud et al, 2002Rainaud et al, , 2005John et al, 2003John et al, , 2004, while supposedly correlative lithologies in the Zambezi Belt were also deformed and metamorphosed during the Lusakan (%840 Ma) Orogeny (Hanson et al, 1994). The depositional age and duration of the Roan Group has been very poorly constrained, with the available data suggesting a range between %1200 and 870 Ma (Cahen et al, 1984).…”