Genesis and age of Pb−Zn mineralization from the Ningi-Burra ring complex, North Central Nigeria: Constraints from zircon morphology, U−Pb dating and Lu−Hf isotopes

Petrogenesis and tectonic implication of the alkaline ferroan granites from Ropp complex, north‐central Nigeria: Clues from zircon chemistry, U–Pb dating, and Lu–Hf isotope

“…The progressive southern shift of magmatic centres has deposited abundant syenites, gabbros and anorthosites, peralkaline granites, and volcanic rock sequence (e.g., rhyolite‐ignimbrite and basalt‐hawaiite‐trachyte) in Niger alkaline province. The alkaline‐peralkaline syenite‐granites and volcanics such as rhyolites and ignimbrites predominate in the northern part of the Nigeria alkaline province (Bowden et al, 1987; Vincent et al, 2021). Their abundance, however, diminishes towards the central and southern part, where the Sn–Nb ± (Pb–Zn ± Mo) mineralized biotite granites constitute the dominant rock unit (Amuda et al, 2020; Bowden et al, 1987; Girei et al, 2019, 2020).…”

“…The onset of Nigerian alkaline magmatism is marked by the eruption of rhyolitic, ignimbritic, and basaltic rocks with minor hawaiites, mugearites, and trachytes during the volcanic phase (Bowden et al, 1987). These rocks commonly occur in the northern part (Figure 1b), where the underlying granitic rocks are exposed only within the deeply eroded zones, as exemplified in Ningi‐Burra, Saiya‐Shokobo, Banke, and Ririwai complexes (Girei et al, 2019; Ike, 1985; Macleod et al, 1971; D. C. Turner & Bowden, 1979; Vincent et al, 2021). The volcanic phase was accompanied by large caldera subsidence which triggered the emplacement of epizonal syenites that form elliptical ring complexes (Bowden et al, 1987; Kinnaird et al, 1985) in Kila‐Warji, Zuku, Zaranda, and Jere‐Sanga complexes (Ahmed et al, 2021; Bennett et al, 1984; Macleod et al, 1971; D. C. Turner, 1968).…”

“…The province is a world‐class example of mid‐plate alkaline‐peralkaline anorogenic magmatism notable for its age migration systematically younging from north to south (ca. 214–141 Ma), and rare metal Sn‐Nb ± (Pb–Zn ± Mo) mineralizations (Dickina et al, 1991; Girei et al, 2020; Kinnaird, 1985; Kinnaird et al, 1985; Rahaman et al, 1984; Vincent et al, 2021). The Nigerian alkaline ferroan granites and the Cameroon Volcanic Line lie along the boundary between two Archean cratons.…”

“…Indeed, recent studies have shown that the Nigerian ferroan granites were generated as a result of fractional crystallization of highly differentiated basaltic (OIB) magmas from the enriched lithospheric mantle with variable contributions from the lower crust (Ahmed et al, 2021; Amuda et al, 2020; Girei et al, 2019; Kamaunji et al, 2020). However, other workers (Girei et al, 2020; Vincent et al, 2021) opined that the Nigerian A‐type granites, particularly the highly oxidized and less radiogenic Mo– and Pb–Zn mineralized biotite granites from Mada and Ningi‐Burra complexes, were derived from the lower crust with upper mantle involvement. Their inference is similar to the alkali‐metasomatized and fenitized lower crustal origin hypothesized by Magaji et al (2011) and Sakoma and Martins (2011) for the Geshere and Kwandonkaya A‐type granites in north‐central Nigeria.…”

“…(c) Geological map of the Ropp alkaline ring complex (extracted from Kinnaird et al, 1985). (1) Rahaman et al (1984), (2) Van Breemen et al (1975), (3) Van Breemen and Bowden (1973), (4) Dickina et al (1991), (5) Girei et al (2019), (6) Kamaunji et al (unpublished data), (7) Kamaunji et al (2020) (8) Ahmed et al (2021), (9) Van Breemen and Bowden (1973), (10) Vincent et al (2021), (11) Amuda et al (2020), (12) Girei et al (2020). Ages of Air and Damagaran in Niger Republic are based on Rb–Sr dating obtained from Bowden et al (1976).…”