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Field geologic occurrence and petrographic characteristics of precambrian marble body in Itobe area, Central Nigeria

Onimisi M., Obaje N. G. and Daniel A.

Field geologic mapping and petrographic studies involving X–Ray Diffraction (XRD )analysis of the Precambrian marble body in Itobe area, central Nigeria reveals the occurrence of two marble outcrops (described as mass I and mass II). Mass I, which occurs as a minor lensoid body, is light gray, fine grained and outcrops at a road cut about 150m from Alo Village. Mass II, which outcrops on the Ayanka hill about 800m from mass I along a NE–SW axis, is dark gray and medium grained. The Itobe marble body and the host rocks of mica/quartz schist and quartzite trend in the NNE – SSW direction; parallel to the dominant foliation trend of the associated basement rocks. (XRD) analysis of the marble reveals an average mineralogical composition of Dolomite (33.3%), Calcite (64.9%) and Quartz (1.8%) for mass I and Dolomite (1.7%), Calcite (92.5 %) and Quartz (6.3 %) for mass II.