Abstract:
Shendi-Atbara Basin is an outerlier surrounded by Precambrian and Paleozoic crystalline rocks. South of Shendi, the basement is exposed at the Sabaloka inlier, and Butana plain at the east. The Shendi-Atbara
Basin is now considered as an important target for hydrocarbon exploration in central Sudan. The study area is bounded by the longtitude 16°23'52.30"and 17° 15' 30.30'' & latitude 33018'51.9''and 33° 43" 33.85' , in eastern and western parts of River Nile State. Study area is dominated by Mesozoic sediments of continental origin from
fluvial and lacustrine depositional environments which are widely
spread in central Sudan. During the field work trip, fourteen vertical
and three lateral sedimentary profiles have been examined and
discussed. The studied profiles exhibit eleven lithofacies identified at
the outcrop section which are matrix supported massive conglomerate
(Gmm) facies, stratified conglomerate (Gt), trough cross-bedded
sandstone facies (St), Shallow scour pebbly sandstone (Ss), planar
cross-bedded sandstone facies (Sp), horizontally –bedded sandstone
facies (Sh), ripple cross-bedded sandstone facies (Sr) , massive
sandstone facies (Sm), massive mudstone (Fm), fine-laminated
mudstone (Fl) and rootbed mudstone (Fr). The study aims to the
interpretation of depositional environment using lithofacies analysis.
On the basis of their sedimentological character theses f a c i e s are
interpreted to be deposited in fluvial depositional environment , by
multi braided river channels. Representative samples were subjected to
various preparation methods to permit its investigation, both
mechanically and microscopically. The laboratory methods include:
grain size analysis, determination and calculation of statistic coefficient
using Microsoft Office Excel software, drawing the sedimentary
profiles using sed.log software , preparing maps using ArcGIS software
for digital image processing, petrographic description, total organic
carbon (TOC) analysis , heavy minerals analysis, palynological
analysis & scanning electron microscope (SEM). The samples are very
poor in term of TOC and hydrocarbon potential, they are barren in
palynomorphs, the main cementing material is clay (Kaolinite &
Chlorite) with low concentration, no significant concentration of heavy
minerals is observed.
