6533b835fe1ef96bd129f3c6

RESEARCH PRODUCT

Single zircon evaporation ages from the Oban Massif, southeastern Nigeria

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Abstract A single zircon geochronological study in the Oban Massif of southeastern Nigeria, using the evaporation technique, provides evidence for the existence of Palaeoproterozoic crustal components in the area. The banded gneiss in the Oban village yielded a 207 Pb 206 Pb age of 1931.9±0.8 Ma, whilst charnockites associated with this gneiss provided an emplacement age of 584.5 ± 1.0 Ma. The volumetrically most important intrusive unit in the Oban area is a granodiorite that yielded a zircon age of 616.9 ± 1 Ma. These ages suggest that the banded gneiss is the oldest rock in the Oban Massif and that the emplacement of granodiorite and the formation of charnockites took place during the Pan-African Orogeny.