Late Proterozoic schist belts and plutonism in NW Nigeria

Abstract

The deformed, low-grade, metasedimentary-volcanic schist belts of NW Nigeria, and the voluminous granitoid plutons which invaded them, are expressions of late Proterozoic-early Phanerozoic activity in the terrain separating the W African and Congo cratons. Recent interpretations of Nigerian geotectonic evolution have invoked two generations of schist belt, one a product of Kibaran ( c . 1100 Ma) ensialic processes, the other due to Pan-African (700–450 Ma) marginal basin development. The detailed histories of the Anka Belt (Pan-African), Maru Belt (Kibaran) and Birnin Gwari Belt (unknown age), and the plutons emplaced in them, are documented here on the basis of new field, chemical and isotopic data.* Each belt represents a dominantly quiet-water sedimentary environment but volumetrically minor lithologies reveal important differences between the belts. The volcanic rocks and early minor intrusions have strong affinities with those of destructive plate margins. The schist belts were deformed congruently and simply before c . 750 Ma, following the development of flat-lying, possibly thrust-related structures in the Maru and Birnin Gwari Belts. Subsequent plutonism, beginning c . 750 Ma ago, has the calcalkaline, I-type characteristics of subduction zones but younger plutons have mildly peralkaline compositions due to thickening crust.

Investigating high zircon concentrations in the fine fraction of stream sediments draining the Pan-African Dahomeyan Terrane in Nigeria

“…The Western Terrane comprises three major lithological units -migmatitic gneisses, supracrustal/schist belts and Pan-African plutonic rocks (Russ, 1957;Hockey et al, 1963;Truswell and Cope, 1963;Jones and Hockey, 1964;Dempster, 1966;Grant, 1969;Odeyemi, 1981;Fitches et al, 1985;Ferré et al, 1996;Odigi, 2002;Ajibade et al, 2008). The migmatitic gneisses are lithologically similar to the ubiquitous 'grey gneisses' of many…”

Groundwater Potential and Vulnerability Assessment from Integrated Geophysical Methods, Borehole Logging, and Hydrogeological Measurement

“…Akoko area forms part of the Precambrian Basement Complex of Southwestern Nigeria, comprising mainly of the Migmatite-Gneiss-Quartzite Complex (Figure 3) which is of Archean -Proterozoic age averagely >2Ga [12][13], the Late Proterozoic SchistBelts [14][15] and the Older Granitoids of Pan-African age (500-750Ma) which intruded the former two units [16][17][18]. The area comprises mainly of gneisses in association with other rock types which include porphyritic granite, pegmatite, aplite, quartz vein and amphibolite.…”

Geoelectrical Evaluation Of The Variation In The Spatial Distribution Of Aquifers In The Basement Complex – A Case Study Of Laduga Community, Kaduna State, North Central, Nigeria.

“…It consists of a wide variety of metamorphic and igneous rocks and has been shown to be polycyclic with ages ranging from 2800M.a to 450M.a. The Pan-African event (600±150M.a) was the latest reactivation that affected the whole region (Fitches et al, 1985), and it caused regional metamorphism and deformation which imposed a generally N-S foliation trend and brought about the emplacement of granitoids. The basement complex can be subdivided into three major lithological units which are Migmatite-Gneiss complex; Older Granite and Schist Belt.…”