Monazite EPMA-CHIME dating of Sangmelima granulite and granitoid rocks in the Ntem Complex, Cameroon: Implications for Archean tectono-thermal evolution of NW Congo craton

Akame, Joseph Martial; Schulz, Bernhard; Owona, Sébastien; Debaille, Vinciane

doi:10.1016/j.jafrearsci.2021.104268

Cited by 10 publications

(14 citation statements)

References 71 publications

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“…These cratonic blocks have underwent multiple episodes of large-scale brittle deformation which created large discontinuities within them. Akame et al (2020Akame et al ( , 2021 documented the presence of large NW-SE, NE-SW and E-W trending brittle and ductile shear zones in the Ntem-Chaillu block, inherited from Neoarchean orogenesis. Similar deformation were also reported in the laterally equivalent Souanké Archean rocks in the Ivindo region (Gatsé Ebotehouna et al, 2021;Loemba et al, 2022).…”

Section: Regional Geology Of Western Africa and Continental Marginmentioning

confidence: 99%

“…Akame et al. (2020, 2021) documented the presence of large NW‐SE, NE‐SW and E‐W trending brittle and ductile shear zones in the Ntem‐Chaillu block, inherited from Neoarchean orogenesis. Similar deformation were also reported in the laterally equivalent Souanké Archean rocks in the Ivindo region of Republic of Congo (Gatsé Ebotehouna et al., 2021; Loemba et al., 2022).…”

Section: Geological and Tectonic Settingmentioning

confidence: 99%

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Seismogenic Fault Reactivation in Western Central Africa: Insights From Regional Stress Analysis

Nkodia

Miyouna

Kolawole

et al. 2022

Geochem Geophys Geosyst

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Earthquakes remain one of the most catastrophic natural hazards in human history. Beyond the associated fatalities, earthquakes also leave behind lasting environmental and economic crises in the affected communities. Although, the largest magnitude earthquakes have been recorded along plate boundaries in association with plate subduction, collision, and continental rifting (McCaffrey, 2008), several large magnitude (Mw > 6) events have also been recorded in intraplate regions (e.g., Talwani, 2014;Tuttle et al., 2002), and more intriguingly, along passive continental rift margins where the sources and occurrence of earthquakes remain less understood. Among the large magnitude and devastating earthquakes recorded in continental intraplate regions previously thought to be relatively stable include the Mw 6.2 Latur Earthquake of

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Section: Regional Geology Of Western Africa and Continental Marginmentioning

confidence: 99%

Section: Geological and Tectonic Settingmentioning

confidence: 99%

Seismogenic Fault Reactivation in Western Central Africa: Insights From Regional Stress Analysis

Nkodia

Miyouna

Kolawole

et al. 2022

Geochem Geophys Geosyst

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Section: Regional Geologymentioning

confidence: 99%

“…Eclogitic assemblages or residual seafloor sequences remain mysterious, and subduction processes have developed (Owona et al, 2022). The Precambrian basement of the Ntem Complex (Figure 1c) consists of three major structural units, including (1) the Congo Craton, locally called the Ntem Complex, consisting of Archean cratonic geological formations (e.g., Akame et al, 2021; Maurizot et al, 1986; Pouclet et al, 2007; Tchameni et al, 2010) in the south; (2) the Palaeoproterozoic Nyong Complex (e.g., Bouyo Houketchang et al, 2019; Loose & Schenk, 2018; Soh et al, 2021; Toteu et al, 1994) to the NW of the Congo Craton; and (3) the Neoproterozoic Yaoundé Group (e.g., Kamani et al, 2021; Nzenti et al, 1988; Toteu et al, 2022) representing the southern part of the Central African Pan‐African Range that resulted from the convergence and continental collision at ca. 600 Ma (Figure 1a,b) (e.g., Kamani et al, 2021; Ledru et al, 1994; Owona, Ratschbacher, et al, 2020).…”

Section: Geological Settingmentioning

confidence: 99%

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

2023

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Detailed petrographic, lithostratigraphic, and geochemical data of metamorphosed orthogneisses and mafic‐ultramafic metavolcanic rocks intruded into the greenstone belt of the Toko‐Nlokeng iron deposit have enabled the reconstruction of the tectonic and geodynamic setting and crustal evolution of the Nyong Complex. Samples were collected from the drill holes TNF11_01 and TNF11_02 from 17.16 m to 335.85 m depth. The lithostratigraphy supported by field and petrographic observations outlines two main lithologies: Iron formations (IFs) and metamorphosed host rocks. The IFs (granular iron formations (GIF) and banded iron formations (BIF)) are intercalated with host rocks consisting of orthogneisses and mafic‐ultramafic rocks. New and published geochemical data of metamorphosed associated IFs from Anyouzok (TNF08 prospect) of the Toko‐Nlokeng iron deposit, Mewengo iron deposit, Bipindi, and Kribi metavolcanic rocks in the Nyong Complex, suggest that these rocks were formed by material from intrusive and extrusive magmatic episodes with mid‐ocean ridge basalts (MORB) contaminated by either subduction or crustal components. CaO/Al2O3 and (Gd/Yb)N ratios >1 and positive Nb anomalies in ultramafic rocks indicate a mantle plume source contaminated by metasomatized subduction mantle lithosphere. These data also show that the mafic‐ultramafic metavolcanic rocks derive from magma of basaltic and basaltic andesite compositions, with a tholeiitic to calc‐alkaline tendency characteristic of the upper mantle. These data reveal that gneisses derive from granite and diorite subalkaline, peraluminous, and ferroan to magnesian compatible with Cordilleran magmas and island arcs with polygenetic crustal signatures. All samples of mafic granulites, garnet‐amphibolite, metabasites, and ultramafic granulites in the Nyong Complex reveal no residual garnet and predominantly show ca. 4% partial melting of an amphibole‐spinel‐peridotite source in the Dy/Yb versus La/Yb. Otherwise, hornblendites of Toko‐Nlokeng display ca. 5% partial melting of an amphibole‐garnet‐peridotite source, average (Gd/Yb)CN ratio of the hornblendites is (Gd/Yb)CN = 7.56 > 2. This result suggests these hornblendites do not have the same magmatic source as other mafic‐ultramafic rocks of the Nyong Complex. Mafic‐ultramafic host rock protoliths are classified as E‐MORB, P‐MORB, and G‐MORB (hornblendites) compositional types and arc, back‐arc ‘B’ in subduction unrelated, rifted margin setting with minor crustal contamination. The tholeiitic to calc‐alkaline and peraluminous affinity of these rocks indicate a mature arc and thickened crust during the Eburnean Trans‐Amazonian orogenic belts of the Congo Craton. This study shows that the host rocks were emplaced in a convergent tectonic setting and affected by a syn‐collisional episode where melts were derived from the partial melting of thick basaltic crust into amphibolite–eclogite facies in the subduction zone. The geochemical signatures of the mafic‐ultramafic rocks support the tectonic accretionary of the Palaeoprotero...

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“…This Complex comprises the Paleoproterozoic Nyong complex to the north-west and the Archean Ntem Complex to the southeast (Figure 1c) (Maurizot et al 1986; Tchameni et al 2010; Soh Tamehe et al 2021). The latter consists of tonalite-trondhjemite-granodiorite (TTG) and charnockite suites, potassic granitoid, minor supracrustal (banded iron formations, BIFs; sillimanite-bearing gneisses; garnet-bearing amphibolites and pyroxenites) rocks that represent remnants of greenstone belts (Ganno et al 2017; Ndime et al 2019; Akame et al 2021). Metagabbro and dolerite dykes cross-cut the granite-gneissic basement and greenstone belt.…”

Section: Introductionmentioning

confidence: 99%

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)

Aboula

Ondoa

Ndjigui

2023

Applied Earth Science

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Regional geophysical data are important for detecting the presence of mineral deposits under cover. This study used geophysical data coupled with field geology of the Toko-Nlokeng area, Cameroon, to locate and map structures and lithologies as part of an exploration campaign for mineral deposits. The airborne geophysical survey in the Toko-Nlokeng area located in the Nyong complex revealed a predominantly EW striking highly folded series result of polyphase deformation of iron formations and host rocks divided into domains based on magnetic and radiometric character. The geophysical data indicate that major faults and shear zones strike NE-SW, with N-S striking units on the western margin and mainly E-W striking units in the rest of the area. These data suggest a major N-S thrust fault similar to the Borborema Province (NE Brazil) terrane marked by accretionary processes during the assembly of Western Gondwana. Several significant NE-SW striking shear zones are present. The data revealed many moderate to highly magnetic bodies that are interpreted as magnetite-bearing iron formation, mafic-ultramafic intrusions and flows, skarns, carbonatites and kimberlites. The magnetic and radiometric trends reveal the internal regional rock fabric and strike, and iron ore targets with magnetic anomaly up to 27,000 nT related to iron formations and other significant targets for gold, potassium (alteration) and uranium. The Toko-Nlokeng iron deposit is comprised of magnetite-bearing quartzite beds and is concordant with the surrounding host rocks and stands as one of a broad group of magnetite-dominated iron formations that occur throughout West and Central Africa. A new geological map was produced from mapped lithologies and microstructure characteristics of the iron formations, interpretations of the aeromagnetic data and structural features. The study results have important implications for regional exploration programs.

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Monazite EPMA-CHIME dating of Sangmelima granulite and granitoid rocks in the Ntem Complex, Cameroon: Implications for Archean tectono-thermal evolution of NW Congo craton

Cited by 10 publications

References 71 publications

Seismogenic Fault Reactivation in Western Central Africa: Insights From Regional Stress Analysis

Seismogenic Fault Reactivation in Western Central Africa: Insights From Regional Stress Analysis

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

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)

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