Petrography and Geochemical Characterization of the Neoproterozoic Migmatites Around Mararraban Liman Katagum, Bauchi Nigeria

Year 2022, Volume: 4 Issue: 2, 271 - 293, 04.07.2022

Tahir Garba Ahmad Ahmed Isah Haruna Faisal Abdullahı Fatima Ibrahim Maıkore

Abstract

The migmatitic rocks exposed around Mararraban Liman Katagum, Bauchi Nigeria were studied with a view to determine the Geology, petrography, geochemistry and morphology. The area has various morphological units of migmatites. metatexites occurring as patchy metatexite, diatexites as melanocratic diatexite, mesocratic and leucocratic diatexite. They have various flow structures of ptygmatitic folding that are induced by magmatic flow and this morphological forms of migmatite are associated with one another. Petrographic analysis shows metamorphic mineral assemblage comprises of quartz + plagioclase + biotite ± Microcline ± Muscovite ± orthopyroxene ± silliminite ± garnet ± accessory minerals and a typical abundance of quartz and biotite. The presence of metamorphic optical properties such as undulous extinction in quartz and obliteration of twinning in feldspar, and microstructure such as mymerkite, perthite indicate the rocks were subjected to pressure and temperature, and that partial melting is the main process that form the different suites of migmatitic rocks of the study area. Geochemically, a slight inverse correlation between SiO2 and few elements is observed. This suggests that the classic model of fractional crystallization is not the principal process influencing the lithological diversity but partial melting in which the correlation patterns are controlled by the geochemistry of the solid phases been added to the melt. Various models were used to determine the ancestry of the migmatite in the study area. In all the plots the migmatite fell within sedimentary/ metasedimentary field which suggests that the protolith of the migmatite are of sedimentary or metasedimentary rocks.

Keywords

Migmatite, Metatexite, Diatexite, Petrograhy, Geochemistry

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