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Hello guy. I'll be sharing briefly with you all the geology of the Chad basin.
It's referred to as the Borno basin by many Authors while describing the Nigerian part of the entire Chad region. Whiteman(1982) described the Borno basin as an I'll defined unit situated in the North East top of Nigeria and Eastern side of Kaduna basement massive,north of the Zambuk ridge of the Biu volcanic plateau. The Borno trough may have formed part of the entire Borno-Chad rift trough system which extends from the Air massives to lake Chad. This system nay be part of a failed arm of an aborted right system whose geometry and age cannot be defined.
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Several research has indicated that the Borno trough in Northern Nigeria contains more than 14,000ft of sediments that goes down to 8,000ft below lake Chad. The entire Chad basin occupies 2,030,000km^2 of land covering south of Sudan and central Sahara region.
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It's the largest inland drainage system in Africa. About one tenth of this drainage area extends into Nigeria,which is known as Borno basin.
In Nigeria,east Western unit is the water divide between Niger and lake Chad drainage system and the southern limit is the divide between lake Chad and the Benue drainage system.
The altitude varies from 530m above sea level at the western margin to 300m at the central lake Chad area,indicating a gentle slope towards lake Chad.
STRATIGRAPHIC SEQUENCE
Deposition in the Chad basin started in the upper Cretaceous. During this time,about 1000ft of Bima sandstone was laid uncomformably on the Basement complex although the thickness could be higher in some places .
•The Bima sandstone is poorly sorted,coarse,pebbly and thickly bedded.
•Overlying it is the Gongila formation. The age is Turonian,consists of basal marine limestone.
•Overlying the Gongila is the Fika shale. It's Santonian. Age of the Fika shale is upper Turonian to Sironian,made up of marine shale.
•The Gombe sandstone overlies the Fika shale. It's cross bedded,made of intercalations of siltstones,shales and ironstones but without coal seam interactions. It was deposited during the Maastrichtian in an estuarine/deltaic environment.
•Overlying the Gombe sandstone is the Kerri-Kerri formation of the Paleocene. It consists of grits alternating with cross bedded sandstone and clayey intercalation suggesting deltaic to lacustrine environment.
•The Chad formation is the uppermost formation of the Pleistocene age. It varies considerably laterally and vertically. It varies from 1,000-8,000m gravely to pebbly and gritty sand bed. There's the intercalation of clay, referred to as middle Chad sediment.
Exploratory drilling in search of Oil in the Chad basin will soon be carried out by the Government of the Federal Republic of Nigeria. This is will help boost the oil reserves in the country,while providing employment opportunities for the citizens which would improve the living conditions.
It was suspended due to security reasons in the region .
Thanks for reading,I hope you find it educative and interesting. Please do leave a comment.