The petrostructural characteristics and 207Pb/206Pb zircon data from the Ngomedzap-Akongo area (Nyong complex, SW-Cameroon)

Abstract

Herein, we constrain the Ngomedzap-Akongo geodynamic evolution in the eastern part of the Nyong complex (NyC) in SW Cameroon that belongs to the Paleoproterozoic West Central African Fold Belt (WCAF) through petrostructural field observations, laboratory analyses, and 207 Pb/ 206 Pb zircon geochronology. It consists of magnetite bearing quartzite, metagranodiorite, metaanorthosite, metagabbro, and metasyenites that have recorded a polyphase D 1-D 3 deformation. D 1 , likely a pure shear-type, has been strongly overprinted by the D 2 transpression flow regime that emplaced the Nyong tectonic nappe, transported top-to the East onto the Congo shield. This nappe is dissected by D 3 blastomylonitic shear-zones. Both the D 2 and D 3 have controlled the actual geometry of the Nyong belt, later crosscut by D 4 multiple brittle tectonic styles, likely post-orogenic. Zircon geochronology yielded 207 Pb/ 206 Pb zircon geochronology protolith Archean mean ages of 2764 ± 26 Ma (MSWD = 0.81) in metagranodiorite; 2816 ± 34 Ma (MSWD = 1.3) and 2789 ± 13 Ma (MSWD = 0.28) in metasyenites. These new data corroborate old ones and, together, document the Archean origin of the NyC as details of the Nyong fold-and-thrust belts that of WCAFB and South American homologous due to the colliding Congo-San Francisco shields associated with Eburnean/Trans Amazonian orogeny (~2100-2050 Ma).

Laterization Process Recognition along the Northern Border of the Congo Craton by Geoelectrical and Geotechnical Data

“…Cameroon developed on the stable continental surface by isostatic readjustments and by putting aside the old lineaments (zones of great deformation) [11]. We have hydromorphic soils represented by the alluvial soils of sedimentary basins and the soils of the low swampy depths of forests.…”

Petrology and geochemistry of metamorphosed rocks associated with iron formations of the Toko‐Nlokeng iron deposit, (Southern Cameroon): Implications for geodynamic evolution and mineralization

“…The Nyong Complex is generally considered to have been in an oceanic lithosphere subduction environment during the Palaeoproterozoic (Bouyo Houketchang et al, 2019; Loose & Schenk, 2018; Owona et al, 2022). Eburnian metamorphism is associated with syn‐and post‐tectonic magmatism where the low‐pressure metamorphic type developed beneath a volcanic chain in the adjacent island arc or continental margin and the high‐pressure metamorphic one developed beneath a trench zone with a compressional regime later overprinted by transpression and thrust tectonic faults (e.g., Kamani et al, 2021; Lerouge et al, 2006; Owona, Mvondo, et al, 2020). This work presents the lithostratigraphic, petrographic, and geochemical data of mafic‐ultramafic rocks associated with IFs collected from 17 to 410 m depth.…”

Mapping geological configuration using geophysics data: an investigative approach in targeting iron ore, gold mineralization and other commodities, a case study of Toko-Nlokeng area (Nyong Greenstone Belt, SW Cameroon)

“…These pathway fluids are genetically linked to ore formation (Cox 2010; Ford and McCuaig 2010; Bark and Weihed 2012; Kreuzer et al 2019; Zhang and Zhou 2015; Santos et al 2017; Ford 2020; Montsion et al 2021; Combes et al 2022; Kwak et al 2022). The structural evolution of the Nyong Complex greenstones belt within the margin of the Congo craton in Cameroon is still poorly documented for it was strongly deformed and reworked during collision between the Congo-São Francisco and the West African cratons associated with Eburnean/Trans Amazonian orogeny (Owona et al 2020).…”

“…In Cameroon, iron formations and gold mineralization are found in the Ntem complex and the Nyong Complex where they form an iron belt extending from Mbalam to Kribi, over a length of nearly 500 km (Suh et al 2008; Ganno et al 2015; Evina Aboula et al 2023a, 2023b). the Southwest Cameroon can be divided into three major tectonic units separated by regional-scale thrusts; these are the Ntem Complex, Nyong Complex and Yaoundé Group (Shang et al 2010; Bouyo Houketchang et al 2019; Owona et al 2020). The Nyong Complex belongs to the NW corner of the Congo craton and remains a part of the N–S trending Eburnean-Trans Amazonian West Central African Fold that covers along the western lateral of the Congo craton from Angola to Cameroon and continues to NE Brazil (Feybesse et al 1998; Bouyo Houketchang et al 2019; Caxito et al 2020; Owona et al 2020).…”