On the evolution of the Kazaure Schist Belt of NW Nigeria: a re-interpretation

Abstract

All previous models of evolution of the Kazaure Schist Belt (KZSB) invoked a simple ensialic mechanism in the context of Pan-African deformation which led to the formation of a marginal back-arc basin floored by continental materials that accepted sediments. The closure of these basins in Pan-African times led to the deformation and metamorphism of the sediment and reactivation of older sediments. Taking into account the presence of Banded Iron Formations (BIFs), metavolcanics and the Kalangai-Zungeru-Ifewara (KZI) fault in the belt, a new model of its evolution is proposed. The new model of evolution of the KZSB considers the evolution of the belt by invoking a simple ensialic mechanism under extensional and compressional regimes, in the context of both Eburnean and Pan-African deformations, as well as Pan-African intrusion of calc-alkaline granites and volcanics. It is effective in explaining the occurrence of BIF, quartzites, conglomerates, and Pan-African granitoids in the belt; and emphasizes the presence of the KZI fault in the evolution of the Kazaure belt. The study led to the conclusion that the belt has formed through ensialic processes, and an evaluation of previous data suggested in previous works is consistent with the new view that the KZSB may represent remnants of Paleoproterozoic cover rocks infolded within an Archaean migmatite-gneiss complex during an Eburnean event, and become reactivated during the Neoproterozoic Pan-African event.

Delineation and Correlation of Lineaments Using Landsat-7 ETM+, DEM and Aeromagnetic Datasets: Basement Complex of Shanono, Northwestern Nigeria

“…The areas with lowest signals (blue) are dominated by the gneisses. The greenish zones are dominated by part of the gneisses and the mylonites; orange and yellow areas by some medium-coarse grained granites and gneisses [37].…”

Petrography and geochemistry of Neoproterozoic charnockite–granite association and metasedimentary rocks around Okpella, southwestern Nigeria

“…1a). The complex is composed of three major rock groups: the Migmatite-Gneiss Complex with ages ranging from Neoproterozoic to Paleoproterozoic and Archean (Grant 1970;Rahaman 1976aRahaman , 1988Dada 1998;Krӧner et al 2001;Ekwueme 2003a;Ganev 2012, 2015); low-grade, younger metasedimentary and metavolcanic rocks which formed the Schist Belts considered to be of Neoproterozoic age with most dates varying between 690-489 Ma (Turner 1983;Elueze 1988;Odeyemi 1988;Rahaman 1988;Omitogun et al 1991;Caby and Boessé 2001;Danbatta 2008;Fagbohun et al 2020); and the Older Granite suite which intrude the two earlier lithologies and have Pan-African ages (Rahaman 1976b;Ferré et al 1998Ferré et al , 2002Ekwueme 2003b;Adetunji et al, 2016Adetunji et al, , 2018Girei et al 2019;Ibe and Obiora 2019;Bute et al 2019). The available ages of the Pan-African granites in Nigeria are bracketed between 650 and 580 Ma (Tubosun et al 1984;Rahaman et al 1991;Dada et al 1993;Dada, 1998;Goodenough et al 2014;Bute et al 2019).…”