RMZ – MATERIALI IN GEOOKOLJE

360 Akinola, O. O., Talabi, A. O.A quarry site is located along Epe roadwhere a gneissic outcrop serves as asource of stone aggregate for more thanthree decades. Local sources indicatethat most of the roads in the area werebuilt with products from this stone mill.The major quartzite ridge of the area hasbeen quarried locally to produce materialsfor foundation works and cementmixing for concrete slabs.ConclusionIjero-Ekiti is within the BasementComplex terrain of southwestern Nigeriaand underlain by gneisses, quartzite,epidiorite, schists, granite and pegmatite.The granite and pegmatite formsteeply dipping intrusions into olderrock sequences. Most of the basementrocks are rich in quartz, feldspars, biotiteand hornblende. Calc-gneiss is enrichedin calcite and epidiorite has highpercentage of ferromagnessian mineralsincluding hornblende, biotite, andpyroxene. The mineralogical variationsalso reflect in the chemical compositionof the rocks for instance, calc gneisshas high percentage of CaO and MgOwhereas the gneisses, quartzite, graniteand pegmatite are highly siliceous.Physical properties of the basementrocks indicate that they possess averagespecific gravities, moderate wetdensities, high compressive strengths,and low porosities. A slightly acidic tomildly basic pH characterizes the rocksand they are comparable to similarrocks found elsewhere within the basementcomplex. Economic evaluationindicates that the gneisses, quartzite,epidiorite and the granite have compressivestrength values within the limitsrequired for use as foundation materialand building stones.AcknowledgementThe authors wish to acknowledge withgratitude all those who assisted in thegeological field work. Mr. O. Olaifaof the department of Earth Sciences,Olabisi Onabanjo University Ago-Iwoye and Mr. Nasirudeen of ObafemiAwolowo University, Ile-Ife are appreciatedfor their considerable supports.Numerous colleagues and studentswho contributed in various ways arealso acknowledged. Chemical analysiswas executed at Actlabs laboratories,Canada. Dr. A. F. Abimbola was exceptionallysupportive.ReferencesAjibade, A. C. (1976): Provisional classificationand correlation of the schistbelts of Northern Nigeria. Kogbe, C.A. Ed. Geology of Nigeria. Eliz. Pub.Co. Lagos, pp. 85–90.Ajibade, A. C. (1980): Geotectonic evolutionof the Zungeru region Nigeria.Unpub. Ph.D Thesis Univ. Col. Wales,303p.RMZ-M&G 2012, 59