Geochemical and palaeocurrent analysis of the Tertiary Kerri–Kerri Formation in the Gongola Sub-Basin of the Northern Benue Trough North-eastern Nigeria: implications for provenance, tectonic setting and palaeoweathering

Abstract

Geochemical and palaeocurrent analysis was carried out on the sediments of the Kerri–Kerri Formation in the Gongola Sub-Basin of the Northern Benue Trough, North-eastern Nigeria in order to infer their provenance, tectonic setting and palaeoweathering conditions in the source area. The sediments of the Kerri–Kerri Formation were geochemically classified as litharenite and greywackes. Provenance studies suggested derivation from pre-existing sedimentary rocks with little influence from felsic igneous rocks, while the tectonic discrimination parameters suggest continental rift of passive margin setting. The weathering indices such as chemical index of alteration, plagioclase index of alteration and chemical index of weathering indicate low to moderate intensity of chemical weathering in the source area. Index of compositional variation and SiO2/Al2O3 indicate that the studied sediments are compositionally mature to immature. The palaeocurrent analysis of the Kerri–Kerri Formation suggested south western direction, which indicate that the sediment were source from the north eastern direction. From the provenance studies, source area weathering, and palaeocurrent direction of the Kerri–Kerri Formation, it can be inferred that most of the sediments are from pre-existing Cretaceous sedimentary rocks of the Gongola Sub-Basin and have not undergone long transportation.