Petrology and geochemistry of the Neoproterozoic Nguba and Kundelungu Groups, Katangan Supergroup, southeast Congo: Implications for provenance, paleoweathering and geotectonic setting

19 page(s

Brittle faulting, Co-Cu-suplphide remobilization and tectonic stress in the Lufilian Arc and its foreland (Katanga, D.R.Congo)

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Paleostress analysis and active tectonics in the Pan-African Lufilian Arc and its Foreland around Mweru Lake

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Lithostratigraphy, basin development, base metal deposits, and regional correlations of the Neoproterozoic Nguba and Kundelungu rock successions, central African Copperbelt

The Neoproterozoic Katangan Supergroup comprises a thick sedimentary rock succession subdivided into the Roan, Nguba, and Kundelungu Groups, from bottom to top. Deposition of both Nguba and Kundelungu Groups began with diamictites, the Mwale/Grand Conglomérat and Kyandamu/Petit Conglomérat Formations, respectively, correlated with the 750 Ma Sturtian and (supposedly) 620 Ma Marinoan/Varanger glacial events. The Kaponda, Kakontwe, Kipushi and Lusele Formations are interpreted as cap-carbonates overlying the diamictites. Petrographical features of the Nguba and Kundelungu siliciclastic rocks indicate a proximal facies in the northern areas and a basin open to the south. The carbonate deposits increase southward in the Nguba basin. In the southern region, the Kyandamu Formation contains clasts from the underlying rocks, indicating an exhumation and erosion of these rocks to the south of the basin. It is inferred that this formation deposited in a foreland basin, dating the inversion from extensional to compressional tectonics, and the northward thrusting. Sampwe and Biano sedimentary rocks were deposited in the northernmost foreland basin at the end of the thrusting. The Zn-Pb-Cu and Cu-Ag-Au epigenetic, hypogene deposits occurring in Nguba carbonates and Kundelungu clastic rocks probably originate from hydrothermal resetting and remobilization of pre-existing stratiform base metal mineralisations in the Roan Group.16 page(s

The C2 and C3 formations of the Schisto-Calcaire Subgroup (West Congo Supergroup) in the Democratic Republic of the Congo: An example of post-Marinoan sea-level fluctuations as a result of extensional tectonisms

In the Lower Congo region, the Ediacaran Schisto-Calcaire Subgroup consists of five carbonate-dominated formations (C1 to C5). They record tectono-eustatic sea-level fluctuations controlled by several short-time extensional tectonic events occurred in the whole basin, followed by the development of the Araçuaï-West Congo Orogen between 630. Ma and 560. Ma. The uppermost units of the C2 Formation, i.e. C2d and C2e members, consist of open marine to peritidal/sabkha cycles of 1-4. m in thickness formed during in a Highstand Systems Tract (HST). The unexposed transition between the C2 and C3 formations is interpreted as a 'final' HSTphase which initiated the burial of the carbonate ramp by prograding siliciclastics or an early Transgressive Systems Tract (TST) phase. The carbonates of the C3 Formation represent open marine shallowing-upward cycles of 3-8. m in thickness, with deposition at the top of massive oolitic barrier shoals during a TST which flooded the entire the Neoproterozoic West Congo Basin. During the highstand, contributions of river water and land-derived material inputs occured, intermittently according to the semi-arid to arid conditions that prevailed in the restricted inner ramp and in the sabkha facies belts. In term of geochemistry, the disturbed δ13C trends of the post-Marinoan C2 and C3 carbonates rather reflect early diagenetic variations related to (i) the mixing of carbonate rocks with 13C and 18O depleted fluids including decarboxylation during early organic diagenesis and deep burial, or (ii) the meteoric alteration during carbonate stabilization, than temporal signals of the global ocean chemistry. This observation does not negate the stratigraphic utility of δ13C ratios for intrabasinal correlations.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

The neoproterozoic west-congo “Schisto-Calcaire” sedimentary succession from the bas-congo region (Democratic republic of the Congo) in the frame of regional tentative correlations

New detailed lithological, sedimentological, major chemical, δ13C and δ18O stable isotopes data were obtained from exploration drilling samples on carbonate formations of the Neoproterozoic Schisto-Calcaire Subgroup (> 635-575 Ma) in the Lukala area (Bas-Congo, Democratic Republic of the Congo). This work characterizes and reinterprets the stratigraphical succession from the C2 (Bulu) up to the C4 (Lukunga) formations. The C3 (Luanza) Formation is subdivided into four submembers and the transition of the C3 Formation with both the C2 and C4 formations is examined. New δ13C and δ18O stable isotope data obtained complete the dataset for the Schisto-Calcaire Subgroup in the frame of a correlation with the same succession in Gabon and the Republic of the Congo. The aged equivalent stratigraphic units and lithologies of the West-Congolian (WCB), Katangan (CAC) and Bambuí (SFB) successions are examined, compared and coupled with the available carbon and oxygen isotope values, and a regional correlation is proposed.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Sources of sulphur in the Katanga Copperbelt, Democratic Republic of Congo

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Palaeostress reconstruction in the Lufilian Arc and the Kundulungu foreland (Katanga, Democratic Republic of Congo): in search of evidence of incipient active rifting

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