RARE EARTH EVIDENCE FOR THE ORIGIN OF GNEISSES AROUND YARI BORI AND TSIGA AREA, PARTS OF MALUMFASHI SCHIST BELT, NIGERIA.
DOI:
https://doi.org/10.56892/bima.v2i01.54Keywords:
REE; gneisses; fractionation; chondrite; schist belt; Malumfashi.Abstract
There is variability in the total Rare Earth Elements (REEs) abundance, their distribution
patterns and degree of fractionation in the gneisses of Yari Bori and Tsiga area parts of
Malumfashi schist belt of Nigeria. The variety of gneisses mapped includes granite gneisses,
augen gneisses and the banded gneisses. Most of the gneisses investigated shows marked
negative Eu anomalies. Also the REE distribution patterns are significantly fractionated with
strong light REE enrichment (La, Ce, Pr, Nd, Sm and Gd,) and heavy REE depletion (Tb, Dy,
Ho, Er, Tm, Yb, Lu); a suggestive of melt equilibration with residual garnet. La is in the
range of 10.7-81.5 ppm, Ce (21.6-174.6 ppm) and Pr (2.39-20.29 ppm) while Tm is in the
range of 0.05-0.73 ppm, Yb (0.30-4.62 ppm) and Lu (0.04-0.67 ppm). The gneisses of this
area are interpreted as resulting from magmatic origin involving varying degree of partial
melting of lower crust at different depths.
