Lithological characteristics and structural analysis of basement complex rocks of Danko, Zuru Schist Belt, Northwestern Nigeria: Implication for structural evolution

Abstract

The lithological and structural characteristics of Danko northwestern part of Zuru Schist 
Belt have been investigated and analyzed with the aim of unraveling the structural evo
lution of this part of the basement complex. The area comprises of muscovite schist, 
quartzites, quartz schist, and late post-tectonic granite (fine to medium grained), as well 
as pegmatite and aplite veins and dykes. Field investigation reveal that the basement was 
subjected to three phases of tectonic deformation denoted as D1, D2, and D3. The first 
phase of deformation (D1) was associated with the development of a regional foliation 
S1 on an S0 bedding plane and a flat lying partially obliterated minor asymmetrical fold 
F1. The second phase of deformation (D2) is the main deformation phase, and involved 
a heterogeneous deformation that gave rise to large-scale upright tight to isoclinal folds 
F2 with a NNE–SSW trend of axial plane and an S2 crenulation foliation. D3 deformation 
phase is a late stage phase, which involved brittle deformation marked by late subvertical 
fractures which gave rise to granitic veins, pegmatite, faults, and joints. These extensional 
fractures show a bimodal orientation mainly in WNW–ESE and NW–SE directions that are 
nearly perpendicular to the regional metamorphic foliation.