Geochemical Characterization of the Cretaceous Yolde Formation in Yola Arm, Northern Benue Trough, Northeast Nigeria: Implication for Provenance, Tectonic Setting and Weathering

Abstract

This study examines the major and trace element geochemistry of mudstones and 
sandstones units from the Yolde Formation in Yola Arm of the Northern Benue 
Trough. Five samples from the exposed section in Guyuk were used in this 
investigation. Whole rock and lithogeochemistry analyses were performed on the 
samples using X-ray fluorescence (XRF) at Activation Laboratory, Canada. The 
amount of Na2O and Fe2O3 in the continental crust is depleted, as indicated by a 
comparison of major element values with the average amounts of the upper 
continental crust. The calculated chemical index of alteration falls between 60 and 
85. The majority of samples, however, have values below 50, indicating a low to 
moderate level of weathering. The geochemistry of major elements is not helpful in 
understanding the tectonic setting. with the aid of discriminant function plot of 
trace elements like Th, Sc, Zr, La, Th, and Sc, the majority of the the Yolde Formation 
was formed in the passive continental margin (ACM). Finally, the discriminant 
diagram plot of the major elements shows that the provenance of the Yolde 
Formation is linked to quartzose sedimentary rock.