Field Relationships and Petrography of the Rocks Around Kofayi and Environs, Part of Toro Sheet 148se, Toro L.G.A Bauchi State

A.S. AbdullahI; A.I. Haruna; U.S Umar; A.I. Jibrin; K. Musa; S.D. Abegunde; P.; Lila; B.I. Gani; M.A. Hassan; M.Y. Mohammed; J.K. Ayeni

doi:10.56201/ijaes.vol.12.no8.2026.pg11.27

Field Relationships and Petrography of the Rocks Around Kofayi and Environs, Part of Toro Sheet 148se, Toro L.G.A Bauchi State

A.S. AbdullahI, A.I. Haruna, U.S Umar, A.I. Jibrin, K. Musa, S.D. Abegunde, P., Lila, B.I. Gani, M.A. Hassan, M.Y. Mohammed, J.K. Ayeni

Abstract

The Kofayi area of Bauchi State, north-central Nigeria, exposes a diverse assemblage of crystalline rocks comprising pre-cambrian basement rocks, felsic granitoids of the Kofayi Complex and mafic rocks occurring both as discrete bodies and enclaves within the granitoids. This study investigates the field relationships, petrographic characteristics and geological evolution of these rocks using detailed field observations, structural measurements and transmitted-light petrography. Field relationships indicate temporal and spatial interactions between the Pre-cambrian rocks occurring as migmatites and central mafic and younger felsic intrusions of the kufayi ring complex. Mafic and felsic materials of the complex display intimate association which provided evidence of significant interaction during emplacement and crystallisation. The mafic rocks are dark grey, fine to medium graine that occur as tabular intrusive bodies in the basement rocks and as earliest intrusive suit in the younger kofayi complex. The felsic units are medium to coarse grained and porphyritic with abundant angular to sub-rounded several centimeters-thick mafic fragments commonly at mafic-felsic contact zones incorporated during younger felsic magmatism. Petrographic examination shows that while the mafic rocks are characterised by plagioclase, ferromagnesian minerals and subordinate accessory phases, the felsic rocks are dominated by quartz and feldspar with variable amounts of biotite, muscovite and amphibole. Structural features such as gneissic foliations, boudinages and brittle strcuctures particularly joint systems and fractures further record intense deformation. The combined field and petrographic evidence suggests a multistage geological evolution involving emplacement of the pre-cambrian basement rocks during the Pan-African tectonothermal event, subsequent younger magmatism that involves mafic intrusion, crystallisation and partial consolidation of the mafic material and later emplacement of felsic magma that incorporates and interaction with the earlier mafic material that forms abundant mafic enclaves.

Keywords

Kofayi Complex; Nigerian Younger Granites; Pan-African basement granitoids; mafic enclaves; magma interaction; petrography; field relationships; geological evolution.

References

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Field Relationships and Petrography of the Rocks Around Kofayi and Environs, Part of Toro Sheet 148se, Toro L.G.A Bauchi State

Abstract

Keywords

References

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