Journal of Geology & Geophysics
Open Access

Geochemical evidence of the genetic relationships between gneissic host rock and gem minerals associated with pegmatite bodies in Lokoja, central Nigeria

International Conference on Geology

June 22-23, 2015 Florida, USA

J I Omada1, S S Dada2 and S O Idakwo1

Posters-Accepted Abstracts: J Geol Geosci

Abstract :

Field and geochemical studies of samples of gneissic host rock and NE-SW trending pegmatite dykes in Lokoja area, central Nigeria have been undertaken with a view to determining the genetic relationships between them and the associated tantalite, aquamarine and the REE. Trace elements enrichment patterns in the gneiss is Ba>Zr>Sr>Rb>Zn>Nb>Ga>Sb>Sc>Co>Sc while those in the feldspars are Ba>Zr>Sr>Pb>Rb. Muscovite flakes associated with the pegmatite dykes consist of Rb>Nb>Sn>Ga>Ta. Aquamarine and tantalite have enrichment patterns of Sc>Cs>Ga>Sb and Nb>V>W>Zn>Zr>Sc respectively. This study suggests that the mica gneiss is the possible host (progenitor) of the gem minerals that are enriched in the pegmatite dykes and that within the pegmatite bodies muscovite is more closely associated with gem mineralization than feldspars. The selective enrichment of trace elements in the pegmatite dykes suggests that the crystallizing fluid underwent rock-fluid interaction in which albitization was dominant.