Geochemistry and U–Pb zircon geochronology of granitic gneisses in the Mewengo iron deposits: evidence of Archean fingerprints within the Paleoproterozoic Nyong Group, Cameroon

Djibril, Kouankap Nono Gus; Minyem, Dieudonné; Estelle, Nga Essomba Tsoungui Philomène; Marion, Kwamou Wanang Merline; Patrick, Ayonta Kenne; Brice, Kamguia Woguia; Guimollaire, Nkouathio David

doi:10.1007/s12517-022-10775-2

Cited by 7 publications

(13 citation statements)

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“…The granitic gneisses are associated with IFs in the Nyong Complex iron deposits, well described by Kwamou et al (2021) and Kouankap Nono et al (2022). The rock is intercepted at a 278 m depth (hole TNDF11_01) with various intercalations along the section.…”

Section: Results Of Lithostratigraphy and Petrographysupporting

confidence: 64%

“…The granitic gneiss host rocks of the Toko‐Nlokeng iron deposit are characterized by slight ranges in most major elements, having 61.65–74.45 wt.% SiO 2 , 13.57–14.31 wt.% Al 2 O 3 , 2.44–3.18 wt.% CaO, 1.94–12.68 wt.% Fe 2 O 3 , 2.12–4.17 wt.% Na 2 O, and 1.66–1.98 wt.% K 2 O. Based on the geochemical classification for granitic rocks by Frost et al (2001), samples displayed magnesian, calcic, and peraluminous signatures (Figure 6c–e) like those described and dated by Kouankap Nono et al (2022), within the Ntem Complex. These rocks are characterized by plutons on the outboard portions of Cordilleran batholiths, plutons in island arcs, and plagiogranites (Jenson, 1976).…”

Section: Geochemical Resultssupporting

confidence: 55%

“…Swiffa Fajong et al (2022) combined major, trace, and rare earth elements data of whole metamorphosed rocks associated with IFs with newly published geochemical data from Anyouzok (TNF08 prospect), the northern part of the Toko‐Nlokeng iron deposit. Combining new and previously published geochemical data from various host rock types in the Nyong Complex, including the Mewengo iron deposit (Kouankap Nono et al, 2022; Kwamou et al, 2021), Bipindi (Moudioh et al, 2020; Owona et al, 2022), and Kribi metavolcanic rocks (Mvodo et al, 2022). Gneissic rocks and mafic‐ultramafic host rocks geochemical data are given in Tables 1 and 2 respectively.…”

Section: Geochemical Resultsmentioning

confidence: 99%

“…Total carbon and sulphur were determined by the Leco method (TC003). To assess the geodynamic evolution history and mineralization of the Toko‐Nlokeng iron deposit and the Nyong Complex as a whole and to verify the relevance of previous results, they were plotted in the different discrimination diagrams sets of data: nine (03 samples of Grt‐px gneisses and 03 samples of mafic granulites) from Moudioh et al (2020), eight samples of garnet amphibolites from Kwamou et al (2021), nine granitic gneiss samples from Kouankap Nono et al (2022), 17 samples (07 mafic granulites, 05 garnet‐amphibole gneiss, and 05 garnet‐amphibole gneiss) from Mvodo et al (2022), four samples of metabasites from Owona et al (2022), and 19 samples (8 mafic granulites, and 11 garnet amphibolites) from Swiffa Fajong et al (2022), and 19 samples (8 mafic granulites, and 11 garnet amphibolites) from Owona et al (2022). These data are presented in Tables 1–4.…”

Section: Sampling and Analytical Methodsmentioning

confidence: 97%

“…New and published geochronological studies have been conducted to describe the geodynamic evolution of the Nyong Complex during the Precambrian period (Kouankap Nono et al, 2022; Mvodo et al, 2022; Nzepang Tankwa et al, 2021; Soh et al, 2021; Soh Tamehe et al, 2022). The LA‐ICP‐MS U–Pb on zircon dating of the Nyong Complex metabasic rocks (amphibolites), produced Archean ages of 3072 ± 28 Ma and 2819 ± 12 Ma, which were interpreted as the crystallization ages of their precursors (Nkoumbou et al, 2014; Owona et al, 2021).…”

Section: Geological Settingmentioning

confidence: 99%

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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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Section: Results Of Lithostratigraphy and Petrographysupporting

confidence: 64%

Section: Geochemical Resultssupporting

confidence: 55%