SEQUENCE STRATIGRAPHY OF LATE ALBIAN TO EARLY TURONIAN SUCCESSION IN THE DOMA LIJI STREAM WITHIN THE GOMBE INLIER, PART OF GONGOLA BASIN, UPPER BENUE TROUGH, NORTH EASTERN NIGERIA

Abstract

A detailed geological fieldwork was carried out, and sections were logged. Three lithogenetic
units were encountered within the Late Albian to Early Turonian succession in the Gombe
Inlier. The Bima Group is about 60 meter thick and consists of brown colour, fine to coarse
grained, pebbly trough cross bedded sandstone interbedded with thin clays. It overlies the
basement unconformably, the Yolde Formation comprises of massive to bedded, dark grey to
purple mottled clays and shales, the Fika Formation characterized by thin laminated shale,
silty, fissile shale, oolitic iron stone with Thalassinoides and Skolithos burrows, and dark
grey mudstone containing glauconite, gypsum bed and limestone nodules. The Yolde
Formation in the Doma Liji stream shows a progradational to retrogradational stacking
pattern within an overall transgressive systems tract, with the clinoform prograding into the
sea while the shales above are retrograding land ward. The overall parasequences within the
sequence of Yolde Formation in Doma Liji stream (clinoforms) were products of
transgression that is caused when the rate of base – level rise outspaced the sedimentation
rates at the coastline and normal regression that is caused when the rate of sediment supply
outpaced the creation of accommodation space. The Yolde Formation in the Doma liji
section is interpreted as comprising two parasequence sets (A and B). Set A is represented by
thick tabular cross bedded, fine to medium grained sandstone at the base and grey coloured,
medium grained trough cross bedded sandstone having a progradational parasequence
stacking pattern. Set B represented by dark grey shale inter bedded with thin sandstone with
thalassinoides burrows with a retrogradation stacking pattern. The maximum flooding
surface is here interpreted to be the limestone deposits observed at the upper part along
Doma Liji stream.