Geologica Belgica Geologica Belgica -  volume 17 (2014)  number 2 

Metal sources for the Katanga copperbelt deposits (DRC): insights from Sr and Nd isotope ratios.

Jorik VAN WILDERODE

Department of Earth and Environmental Sciences, KU Leuven, Celestijnenlaan 200E, 3001 Leuven, Belgium

Hamdy A. EL DESOUKY

Geology Department, Menoufyia University, Shebin El-Kom, Egypt

Marlina A. ELBURG

Discipline of Geological Sciences, SAEES, University of KwaZulu-Natal, Westville Campus Private Bag X54001, 4000 Durban, South-Africa

Frank VANHAECKE

Department of Analytical Chemistry, Ghent University, Krijgslaan 281-S12, 9000 Ghent, Belgium

Philippe MUCHEZ

Department of Earth and Environmental Sciences, KU Leuven, Celestijnenlaan 200E, 3001 Leuven, Belgium

Abstract

The ore deposits of the Central African Copperbelt formed during a multiphase mineralisation process. The basement underlying the Neoproterozoic Katanga Supergroup that hosts the ore, demonstrates the largest potential as metal source. Various ore deposits that formed during different mineralisation phases are taken as case studies, i.e. Kamoto, Luiswishi, Kambove West, Dikulushi and Kipushi (Democratic Republic of Congo, DRC). The Sr and Nd isotopic composition of gangue carbonates associated with these deposits is determined and compared with those of rocks from several basement units, bordering or underlying the Copperbelt, to infer the metal sources. The mineralising fluid of diagenetic stratiform Cu-Co mineralisation interacted with felsic basement rocks underlying the region. The Co from these deposits is most likely derived from mafic rocks, but this is not observed in the isotopic signatures. Syn-orogenic, stratabound Cu-Co mineralisation resulted mainly from remobilisation of diagenetic sulphides. A limited, renewed contribution of metals from felsic basement rocks might be indicated by the isotope ratios in the western part of the Copperbelt, where the metamorphic grade is the lowest. The mineralising fluid of syn- and post-orogenic, vein-type mineralisations interacted with local mafic rocks, and with felsic basement or siliciclastic host rocks.

To cite this article

Jorik VAN WILDERODE, Hamdy A. EL DESOUKY, Marlina A. ELBURG, Frank VANHAECKE & Philippe MUCHEZ, «Metal sources for the Katanga copperbelt deposits (DRC): insights from Sr and Nd isotope ratios.», Geologica Belgica [En ligne], volume 17 (2014), number 2, 137-147 URL : https://popups.ulg.ac.be/1374-8505/index.php?id=4467.