Geology, Petrography and Geochemistry of Lukshi Area Around Dass, Sheet 149 SW, Northern Eastern Nigeria

Abstract

The study area Lukshi and its environs is part of Dass sheet 149-SW, Bauchi state,
Nothern Estaern Nigeria. Bounded by Latitudes 10º04'00"N and 9º59’00"N and
longitudes 9º23’00"E and 9º22'00"E. Detailed geological mapping of the research
area was carry out to update the previous geology information of the study area,
the field observation indicates four lithological unite of Migmatite: Diatexite,
Nebulite, Stromatic and Banded orthogneiss. Biotite, muscovite, quartz, feldspar are
the major minerals seen during petrographic studies, and the migmatite showed
little fractionations as they formed from medium temperature minerals to low
temperature (Andesine to Oligoclase) coinciding with anorthoclase and microcline
mineral assemblages at the discontinuous series arm of the Bowen reaction series.
In variations diagrams, the compositional trends for the analyzed sample are
characterized by negative correlation between TiO2, Fe2O3, MgO, CaO & P2O5 with
increased SiO2 but positive correlation between Na2O, K2O and Al2O3 with increasing
SiO2 even though some erratic and scattered distribution are also observed. The
tectonic classifications of different authors indicated that the migmatite are
peraluminous and peralkaline. They formed under syn-collision to late orogenic and
anorogenic tectonic settings