Axis Rotation of a Major F1 Fold during a Retrograde F2 Deformation in Southwestern Nigeria

Simple item page
dc.contributor.authorAdedoyin, Adeonipekun Dele
dc.contributor.authorOjo, Olusola Johnson
dc.contributor.authorAlebiosu, Mercy Titilayo
dc.contributor.authorAdekeye, J.I.D.
dc.contributor.authorBamigboye, O.S
dc.date.accessioned2026-04-29T15:32:41Z
dc.date.available2026-04-29T15:32:41Z
dc.date.issued2017
dc.descriptionResearch Paper
dc.description.abstractNorth east of Ilorin, South-western Nigeria, a NE-SW trending (F₁) fold which was later refolded, was identified in part of the Basement Complex of the country. The area falls within the West African domain of the Pan African (600±150Ma) remobilized metamorphic terrain. Polyphase deformations, which involved at least three tectono-thermal episodes, were also identified. The area falls within the N-S trending Schist Belts where a large-scale sheeted S1 penetrative metamorphic imprint was successively deformed into an overturned antiformal (F₁) fold and, later, to a broad synformal (F2) fold whose axial traces are generally NE-SW and E-W, respectively. The first deformation episode was essentially metamorphic while the subsequent ones were tectonic. Petrological associations indicate that the rocks are mainly gneisses, psamites and psamitic to semi-pelitic schists, cut by Pan African granitoids. These rocks were deformed under high-temperature, low-pressure amphibolite facies conditions, but downgraded from high to medium grade metamorphic interface during a later tectonic event, under a high geothermal gradient within the upper crust. An occurrence of an overturned fold in the northern end of the axial trace of F1 is attributed to irregular strain distribution that culminated in the open F₂ antiform during the third deformation episode. Of interest, within the context of the structural geology of Nigeria, is the E-W trend of the axis of the F2 fold, which is apparently discordant to the observed general N-S structural trends in the Basement Complex of Nigeria. The origin of this latter structure is attributed to localized tangential deformation, culminating in fold axis rotation in the direction of the X axis, and subsequently overturning and tightening of the original F1 fold during the late- to post- tectonic phases of the Pan African tectonism.
dc.identifier.urihttps://uilspace.unilorin.edu.ng/handle/123456789/17780
dc.subjectDeformation
dc.subjectFolds
dc.subjectAxial trace
dc.subjectOverturned
dc.subjectTangential
dc.subjectTectonism
dc.titleAxis Rotation of a Major F1 Fold during a Retrograde F2 Deformation in Southwestern Nigeria
dc.typeArticle

Files

Original bundle
Now showing 1 - 1 of 1
No Thumbnail Available
Name:
Axis Rotation of a major F1 fold.pdf
Size:
4.22 MB
Format:
Adobe Portable Document Format
Download
License bundle
Now showing 1 - 1 of 1
No Thumbnail Available
Name:
license.txt
Size:
1.71 KB
Format:
Item-specific license agreed upon to submission
Description:
Download

Collections