THE POLYCYCLIC RECORDS ASSOCIATED TO THE KIMEZIAN PALEOPROTEROZOIC TERRAINS IN THE KONGO-CENTRAL, DRC: UPDATES AND INTERPRETATIONS
Auteur(s): Makoka Mwanza Frederic, Kanika Mayena Thomas, Makutu Kumakele Douxdoux, Munene Asidi Djonive, Emboni Mulapu Laurent, Musitu Muliwavyo Jonathan, Makutu Ma Ngwayaya Adalbert-Jules, Ongendangenda Tienge AlbertNom de la revue/Journal: JOURNAL AFRICAIN DES SCIENCES
Mois: mai
Volume: 2
Numéro: 1
Année: 2025
pages: 1-19
Résumé
<p>The Kimezian is one of the two highly folded and metamorphic units of the Proterozoic shield in the Kongo-Central province in DRC, and often depicted as a protracted polycyclic recording belt that consists of the diversified gneissic rocks, migmatite, schists, quartzite, quartzophyllade and crystalline limestone, intensively sheared and cataclazed. To understand the geological framework and provide tectonic-magmatic characteristics of this Kimezian unit, we have collected massive field observations along with updated petrographic and structural microscopic data. The results showed that the general trends of rock formations are NW-SE, with isoclinal NE plunging syn-schistose folds. Except for meso-scale foliations and common micro-folds, micro-scale tectonic features including three welloriented muscovite-biotite-sericite flake directions, consistently interpreted as individualized records of three separated orogenic units; shear and rotational features as stress-cinematic turmoil records; recrystallized high-pressure minerals, such the tridymite, kyanite and garnet, as denoting high-degree metamorphism associated at least with one of the orogens; micro-thrust folds (dexter and sinister), micro-faults due to compressive stress regimes. Conversely to widely admitted ideas of two orogens, we suggest that the studied area underwent more than two tectonic-metamorphic events (at least three orogens).</p>