Granulometric analysis of the sandstone facies from the Bima Sandstone in Girei and environs, Yola sub-basin, Upper Benue Trough, Northeastern Nigeria

Abstract

The granulometric analysis of Bima Sandstone in Girei and environs was carried out cov
ering the area within latitudes 9°16’00” and 9°24’00”N and longitude 12°28’00” and 
12°38’00”E. The aim of the study is to determine the grain size distribution of the Bima 
Sandstone, its transportation history, and its depositional environment. Fourteen rock 
samples were subjected to granulometric analysis. The result shows that the sandstone 
is fine, medium to coarse, and very coarse-grained; it is moderate and poorly sorted. The 
graphic mean size ranges from −0.06Ф to 1.03Ф, which suggests high to low flow regime of 
transportation; the inclusive graphic skewness shows positive skewness with few samples 
falling under negative skewness ranging from −0.1 to 2.0; the inclusive graphic standard 
deviation ranges from 1.0 to 1.4; and the inclusive graphic kurtosis ranges from 0.68 to 4. 
The probability plot of the representative rock samples shows that the Bima Sandstone 
was transported by saltation and suspension, while the bivariate scatter plot of Y2 against 
Y3 suggests that the Bima Sandstone is deposited in a continental setting.