Geologic mapping, paleoenvironment and paleoclimate of the South Katanga, Democratic Republic of Congo - Ruwe, Sakabinda, Kayoyo and South Kayoyo districts
Dr. Franck Delpomdor (Illinois State Geological Survey, Prairie Research Institute)
In the Democratic Republic of Congo (DRC), the Precambrian Katangan Copperbelt is a world-class Cu-Co metallogenic province and the largest cobalt-producing mining district in the world. Recently, the World Bank Group funded the DRC’s government for exploring brownfield and unexplored areas. The French Geological Survey has awarded the Illinois State Geological Survey for the geologic mapping and sedimentologic study of the Katanga Supergroup. Four main depositional belts have been identified in the carbonates of the Muombe and Gombela subgoups: basin to slope-outer ramp, storm-influenced outer to mid ramp, mid to inner ramp with an oolitic barrier shoal, and a coastal plain. The post-Sturtian Dolomie Tigrée Member was deposited, under oxic conditions, in a storm-influenced mixed siliciclastic-carbonate distal outer ramp, which was succeeded by an outer to mid carbonate ramp succession. This ramp was flooded by fluvial and gravity flow deposits of the Kaponda Formation. The post-Marinoan Lusele Formation was deposited, under oxic-suboxic conditions, on a mixed carbonate-siliciclastic slope-outer to mid ramp setting, which was flooded by coastal to marine siliciclastic sediments of the Kanianga Formation. The Lubudi Formation was deposited, under oxic conditions, on a tidally-influenced inner ramp, which was rapidly flooded by continental sediments of the Mongwe Formation. In terms of geochemistry, REE+Y distributions predominantly reflected a seawater composition. Two distinct Snowball Earth-type negative δ13C excursions were identified in the Dolomie Tigrée Member and the Lusele Formation, which were correlated with the Rasthof and Maiberg formations in Namibia, C1-C2 formations in DRC, and the lower Sete Lagoas Formation in Brazil, respectively. In terms of paleoclimate, the CIA index indicated warm periods with dry to humid and weak to moderate continental alterations in the Kamoto, Kaponda and Kanianga formations, and cold periods and reduced continental weathering in the Kanzadi, Mwale, Katete and Kyandamu formations.
About the speaker
Dr. Delpomdor is an Associate Sedimentologist at the Illinois State Geological Survey, a division of the University of Illinois’ Prairie Research Institute. He earned a master’s degree and doctorate from Free University of Brussels (Belgium). He has over 10 years of experience in the sedimentology, sequence stratigraphy, basin analysis, chemostratigraphy, and geologic mapping. Dr. Delpomdor has worked on several geologic projects in Central and South Africa, South America, Europe, and recently in East-Central United States.