Genesis and timing of Mo mineralization in the Mada Ring Complex, north-central Nigeria: insights from whole-rock geochemistry, Nd-Sr isotopes, zircon U-Pb-Hf isotopes, and molybdenite Re-Os systematics

Fluorine-rich mafic lower crust in the southern Rocky Mountains: The role of pre-enrichment in generating fluorine-rich silicic magmas and porphyry Mo deposits

“…Fluorine-rich granites and rhyolites are often associated with economic mineral deposits of Sn, W, Be, U, F, Mn, Y, and REEs (e.g., Burt et al 1982;Carten et al 1993;Lüders et al 2008;Dostal et al 2016;Liu et al 2016;O'Neill et al 2017;Dailey et al 2018;Girei et al 2020;Hofstra and Kreiner 2020). Numerous Mo-producing mines in the western United States are also associated with F-rich granites ("Climax-type" deposits; Ludington and Plumlee 2009), and therefore there is considerable interest in exploring the origin and distribution of F-rich granitic For submission to American Mineralogist 5 topaz rhyolites and Climax-type intrusions are often part of bimodal magma suites (Christiansen et al 2007;Ludington and Plumlee 2009), and therefore it is possible that the halogens are introduced into silicic magmas by fluids exsolved from crystallization of mafic magmas that intrude the bases of upper crustal silicic magma bodies, or during deep crustal hybridization related to intrusion of mantle-derived magmas (e.g., Rosera et al 2013;Dailey et al 2018).…”

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 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).…”

“…In addition, controversies still remain regarding the geodynamic evolution of the Nigerian alkaline province. Whether the N–S age migration is driven by reactivated shear zones along ENE–WSW trends (Ahmed et al, 2021; Black et al, 1985; Girei et al, 2019, 2020; Vincent et al, 2022), or is associated with a mantle plume hotspot (Bowden et al, 1976; Kamaunji et al, 2020) require further investigation. In addition, high precision U–Pb zircon dates are needed to further confirm the general trend of decreasing ages from north to south (Amuda et al, 2020).…”