INSTRUMENTAL NEUTRON-ACTIVATION ANALYSIS OF SOME ROCK SAMPLES FROM AKWANA AND ARUFU AREAS, MIDDLE BENUE TROUGH, NIGERIA

Twenty nine (29) major, minor and trace elements including rare earth elements (REEs) were determined by INAA in rock samples from Akwana and Arufu areas, Middle Benue Trough, Nigeria The rock units are located within the lead-fluorite and baryte mineralisation there. The concentrations of the major elements in the tertiary basalt (TB) and dolerite are similar while the elemental abundance in the granite gneisses is completely different. The elemental concentrations in the rock samples do not show any known relationship with fluorite abundance. The concentrations of some elements in both tertiary basalt and dolerite show them to be derived from alkali basaltic liquid. The chondritic normalised REE distribution patterns for the TB are similar to those of BCR-1 but the chondritic relative REE abundance is more enriched in TB than in the BCR-1. The chondritic normalised REE distribution patterns for the granite gneisses are also compared to those of the standard granite samples.