ABSTACT
The Maas trichian-Pale ocene sediments in Yuli area me composed
of the Gombe Sandstone and the Kerri-Kerri Formation. They cover
400 square kilometres have a thichess of more than 100 metres.
Six stratigraphic sections were studied, representing the entire
stratigraphic succession of the Gombe Sandstone i n the Yuli area,
The formation has a thickness of about 30 metres in the studied
area. The Gombe Sandstone consists of folded beds of sandstone,
siltstone and mudstone.
The sandstone consists of well consolidated, texturally immature,
feldspathic wacks which have iron oxide cement. Cross-bedding,
ripple marks, bioturbations, parting lineations and laminations are
the structural features present. The sandstone varieties include
the ferruginous, bioturbated and cross-bedded sandstones. Dark red
slabby sandstones are also present. Texturally the sandstones are
G medium grained, subrounded, poorly to moderately sorted, positively
skewed and leptokurtic. Based on an integrated analysis of the
strati&aphic, petrographic, t e x t u r a l , faunal and structural data,
three environments of deposition may be suggested, namely fluvial,
estuarine , and deltaic.
The Kerri-Kerri Formation consists of horizontal t o near horizontal
strata of sandstone, s i l t s t o n e and clay. The formation overlies
the Gombe Sandstone. It a t t a i n s a thickness of about 70 metres.
laterite capping is very common. The sandstones are f r i a b l e , texturally
immature feldspathic wacks and a few subarkosic arenites. The sand-
I
stones vary from ferruginous sandstones, cross-bedded sandstones t o
pebbly sandstones. The sandstones are coarse t o medium grained,
poorly sorted, very f i n e l y skewed and very platy kurtic. Textural
parametres indicate s a l t a t i o n and suspension as the means of transport
accompanied by rapdd sedimentation. The s t r u c t u r a l features present ,,
include cross-bedding, r i p p l e marks, laminations and slump structures.
The sediments were diposi ted i n Pluvial, Lacustrine and d e l t a i c
environments.
Paleocurrent directions f o r the two formations based on the
r i p p l e marks, cross-bedding, s i z e and rounding trends of the vein
quartz pebbles indicate t h a t t h e c u r r e n t flow was eastwards. The
feldspathic composition of the sandstones from both formations, the
dominance of non-undulose aonocrystalline quartz and quartz pebbles
suggest derivation from the nearby basement complex west of the
studied area. The composition and t e x t u r a l c h a r a c t e r i s t i c s of the
Aeavy minerals present also suggest derivation from the basement
complex west of the area as well as the reworking of the older
sedimentary rocks.
Maduwueze, N (2021). A Sedimentologic and Stratigraphic Study of the Maastrichtian-Pateocene Sediments in Yuil Area, Bauchi State. Afribary. Retrieved from https://afribary.com/works/a-sedimentologic-and-stratigraphic-study-of-the-maastrichtian-pateocene-sediments-in-yuil-area-bauchi-state-1
Maduwueze, NWANYANWU "A Sedimentologic and Stratigraphic Study of the Maastrichtian-Pateocene Sediments in Yuil Area, Bauchi State" Afribary. Afribary, 14 May. 2021, https://afribary.com/works/a-sedimentologic-and-stratigraphic-study-of-the-maastrichtian-pateocene-sediments-in-yuil-area-bauchi-state-1. Accessed 08 Sep. 2024.
Maduwueze, NWANYANWU . "A Sedimentologic and Stratigraphic Study of the Maastrichtian-Pateocene Sediments in Yuil Area, Bauchi State". Afribary, Afribary, 14 May. 2021. Web. 08 Sep. 2024. < https://afribary.com/works/a-sedimentologic-and-stratigraphic-study-of-the-maastrichtian-pateocene-sediments-in-yuil-area-bauchi-state-1 >.
Maduwueze, NWANYANWU . "A Sedimentologic and Stratigraphic Study of the Maastrichtian-Pateocene Sediments in Yuil Area, Bauchi State" Afribary (2021). Accessed September 08, 2024. https://afribary.com/works/a-sedimentologic-and-stratigraphic-study-of-the-maastrichtian-pateocene-sediments-in-yuil-area-bauchi-state-1