Open AccessGeochemical Characteristics and Petrogenesis of Basement Rocks in Idoani Area, Ondo State, Southwestern Nigeria
Author(s) -
Abimbola Chris Ogunyele,
Olatunde Adegbuyi,
Miracle Odindu,
Tunde Erinfolami
Publication year - 2017
Publication title -
international journal of advanced geosciences
Language(s) - English
Resource type - Journals
ISSN - 2311-7044
DOI - 10.14419/ijag.v5i2.8377
Subject(s) - geology , geochemistry , schist , gneiss , phyllite , quartz monzonite , quartz , petrography , petrogenesis , pegmatite , basement , protolith , metamorphic rock , igneous rock , zircon , muscovite , basalt , pluton , paleontology , civil engineering , engineering , tectonics
Idoani area of Ondo State is an extension of the Upper Proterozoic Igarra Schist Belt of the Southwestern Nigerian Basement Complex. The area comprises mainly of metasedimentary rocks with subordinate amount of intrusives. Quartz-mica schist, phyllite, quartzite and banded gneiss are the dominant rock types in the area. These metasediments are intruded by the Older granite and other minor intrusives (pegmatite, aplite, dolerite dyke, quartz vein). Idoani rocks, as revealed by petrographic studies, are rich in quartz, alkali and plagioclase feldspars and mica with a low amount of opaque minerals. Geochemical studies and petrochemical variation diagrams show that the rocks are sub-alkaline, medium-K calc-alkaline to shoshonitic, peraluminous, and characterized by intermediate-high silica content and low-moderate amount of mafic oxides. Petrological and geochemical studies revealed that the quartz-mica schist and phyllite are metapelites while the quartzite is a meta-arkose, derived from a granitic – quartz-monzonitic source. The banded gneisses were probably derived from a hybrid sedimentary–igneous protoliths while the granite is of magmatic origin.