Field and petrographic evidences presented have shown the occurrence of oil residue in Precambrian basement rocks occurring at both the Gongola arm (Gombe inlier) and Yola arm (Billiri-Kaltungo high) of the Northern Benue Trough. Fractures were observed at the Gombe inlier running from beneath the plane of unconformity underlying the Bima formation into the Precambrian basement rocks. Occurrence of oil residue around such fractures implies that they are important routes through which oils are transmitted from the plane of unconformity into the Precambrian basement rocks. Oil residue were not observed in Precambrian rocks of the kaltungo inlier. This is not surprising as direct contact between the sedimentary rocks and basement rocks was not observed at the kaltungo inlier. Oil residue were observed in the Billiri- kaltungo highway, close to inferred contacts between the cretaceous sedimentary rocks and Precambrian rocks in the region. This again confirms the assertion that oils occurring in the basement rocks are fed from sedimentary petroleum source rocks.
Key words: Northern Benue Trough, Petrographic, Lithostratigraphic, Precambrian Basement, Oil residue.
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