THE GEOTECTONIC EVOLUTION OF THE KAZAURE SCHIST BELT IN THE PRECAMBRIAN BASEMENT OF NW NIGERIA
THE GEOTECTONIC EVOLUTION OF THE KAZAURE SCHIST BELT IN THE PRECAMBRIAN BASEMENT OF NW NIGERIA
| dc.contributor.author | DANBATTA, UMAR ADAMU | |
| dc.date.accessioned | 2014-02-05T16:00:38Z | |
| dc.date.available | 2014-02-05T16:00:38Z | |
| dc.date.issued | 1999-10 | |
| dc.description | A DISSERTATION SUBMITTED TO THE POSTGRADUATE SCHOOL, AHMADU BELLO UNIVERSITY, IN PARTIAL FULFILLMENOF THE REQUIREMENTS FOR THE AWARD OF THE DEGREE OF DOCTOR OF PHILOSOPHY ( P h . D .) DEPARTMENT OF GEOLOGY, FACULTY OF SCIENCE, AHMADU BELLO UNIVERSITY ZARIA. OCTOBER, 1999 | en_US |
| dc.description.abstract | In this study, a systematic geological investigation of the Kazaure Schist Belt (KZSB) and its adjacent areas in the basement of northwestern Niqeria have led to the interpretation of its qeotectonic evolution, and the production of a geological map on a scale of 1:100,000. The KZSB consists predominantly of quartettes, politic rocks, and metaconqlomerates. Minor rocks include metavolcanics, meta-sandstones and ferruqinous quartzite s. The Belt as a whole is enclosed by miqmatite-qneiss basement and I-type Older Granites. The mitigate-qneiss basement comprises of mitigate, biotech gneiss and Older Meta-sediments and underlies the Younger Meta-sediments. However the granites are considered to be intrusive into the meta sediments. The Kalanqai Fault System (Truswell and Cope, 1963) of Birnin Gwari-Malumfashi Schist Belts is shown to extend into the KZSB and even beyond. It has produced fault breccias and granitic rocks which have now been studied in detail. The rocks in the area have been subjected to at least two intense phases of ductile deformation (Dj and D2), which conform to a pattern of recumbent N-S trending Fl folds locally refolded to NNE-SSW trending upright F2 folds and affected by granite intrusion and heterogeneous strain related to faulting. The deformation events were accompanied by two viii phases of progressive regional metamorphism followed bv a static metamorphic phase. The first phase of reqional metamorphism attained amphitheater fancies (Mj), whilst the second phase was of revanchist fancies (M2). The granitic rocks in the KZSB have limited range in SiO2 (69.76-72.03%), have hiqh alkali contents, low CaO and MqO values and a Sand index of < 2. In the meta-sediments the values of potash are higher than those of soda, contents of alumina are hiqh, MqO is in excess of CaO, while there is relative liqht R.E.E. enrichment relative to heavy R.E.E depletion in the schists. Geochemical characterisation indicates the Kazaure qranitoids to be I-type qenerated in a syn-collisional settinq and the metasediments oriqinated from post-Archaen qreywacke-type sediments. Five samples of a syntectonic coarse-qrained porphvritic qranite define a 4-point, whole-rock Rb-Sr. errorchron correspondinq to an aqe of 592 +14 Ma with an initial ratio of 0.7097 + 0.0004. This is distinctly a Pan-African aqe and is taken as the crystallization aqe of the qranite. The aqe of D1 and D2 deformations and metamorphisms in the Kazaure Belt is therefore shown to be Pan-African. However the Younqer Granite rocks of the Daura Iqneous Complex rocks were emplaced much later durinq the Mesozoic era (Jacobson et al.. 1964). ix These with other supportive qeological data from adiacent schist belts have allowed the erection of a model of evolution for the KZSB. The KZSB evolved throuqh ensialic processes on the miqmatite-gneiss basement with the protoliths forminq the metasediments deposited in a predominantly shelf or deltaic environment to allow deposition of coarse clastic sediments. This model has specifically been linked to basinal marqin development related to the compressional reqimes of the Pan- African subduction at the West African craton marqin. The Kazaure basin developed as a result of dominq, extension and continental riftinq due to back-arc spreadinq related to the Pan-African subduction. | en_US |
| dc.identifier.uri | http://hdl.handle.net/123456789/359 | |
| dc.language.iso | en | en_US |
| dc.subject | GEOTECTONIC, | en_US |
| dc.subject | EVOLUTION, | en_US |
| dc.subject | SCHIST, | en_US |
| dc.subject | BELT, | en_US |
| dc.subject | PRECAMBRIAN, | en_US |
| dc.subject | BASEMENT, | en_US |
| dc.subject | NIGERIA | en_US |
| dc.title | THE GEOTECTONIC EVOLUTION OF THE KAZAURE SCHIST BELT IN THE PRECAMBRIAN BASEMENT OF NW NIGERIA | en_US |
| dc.type | Thesis | en_US |