Geochemical Composition of Biotite within the Bauchi migmatites: Petrogenetic and Metallogenic Implication

Abstract

Biotite is one of the most important ferromagnesian sheet silicate mineral constituents of the migmatites and associated granitoids. Its composition plays a vital role in understanding petrogenesis and ore- forming processes. This work on biotite aims at investigating or providing a platform on the petrography and mineralogy of biotite within the migmatites of the study area and to understand the formation conditions of the biotite in order to ascertain the significance of this mineral in terms of petrogenesis and mineralization. The data indicates that the biotite are Mg-Fe rich biotite that relatively have high Mg, Al and Fe concentration and low Ti concentration which indicates that the biotite developed under conditions of high oxygen fugacity suggesting that the migmatite morphology that host magma-hydrothermal mineralizations and probably give information on migmatite morphology that host Gold mineralization. From its composition we identified information about the protolith melting process, P/T condition which conclude that they have crustal source signatures (metasedimentary) indicating S-type signatures and formed in a collisional environment under a temperature and pressure range of 4200c – 5200c and 4 – 5kbar respectively.