The Neoproterozoic Central African Copperbelt is a world-class metallogenic province characterized by sediment-hosted stratiform Cu-Co ore deposits and polymetallic vein-type deposits. Two main mineralization phases have been recognized in the Katanga Copperbelt (Democratic Republic of Congo). The first phase occurred during early to intermediate diagenesis and the second during deep burial and the Lufilian orogeny. The Rare Earth Element and Yttrium (REY) concentrations of gangue dolomites associated with the second mineralization phase at the Kamoto and Luiswishi ore deposits were determined and compared to those
of their respective host rocks. Kamoto samples exhibit convex Upper Continental Crust-normalized patterns with a pronounced light REE depletion without significant Eu anomalies and with positive La anomalies. The Luiswishi samples exhibit either progressively increasing REY patterns or ramp-shaped patterns with minor mid REE-heavy REE fractionation, accompanied by pronounced negative Ce and Eu anomalies. These differences suggest that a more intense metamorphic overprint at Luiswishi contributed to the differences with the Kamoto deposit.
Dr. Lieve Balcaen and Prof. dr. Frank Vanhaecke are affiliated with the Atomic and Mass Spectrometry Research Group, Department of Analytical Chemistry, Ghent University, Krijgslaan 281-S12, B-9000 Ghent, Belgium.