Geological Exploration of Marble Deposits in Toto Area, Nasarawa State, Nigeria

Abstract

Geological mapping as well as chemical analysis for marble deposit in the Muro-Obugu-Panda area of Toto Local Government, Nasarawa State, Nigeria, was carried out. The objectives of the study are to first map out the extent of the deposit and then evaluate its chemical characteristics. The geology of the area forms part of the Upper Proterozoic low-grade (green schist facies) schist belts of Central Nigeria, and consists of schists, banded iron, quartzite, and marble. Geological mapping revealed that the marble deposit stretches in a NE-SW direction, from Muro in the north to Kolo in the south, covering about 28 km2. This deposit consists mainly of silicified gray and white varieties of marble. The mapping also identified three (3) exploration targets A—Panda, B—Obugu, and C— Soka. Chemical analysis of eight (8) selected samples shows that CaO content varies from 3.72 to 53.12 wt%. Other impurities are Fe 2 O 3 , Al 2 O 3 , MgO and SiO 2 . Plot of Na 2 O + K 2 O vs. SiO 2 shows a positive correlation while that of CaO and MgO exhibits a well defined negative correlation with SiO2 and this reflects the introduction of chert during the deposition of the parent limestone of the marble body. The variation plot of CaO vs. MgO shows an inverse relationship. This is reflected in the inverse relationship in the proportion of calcite to dolomite in the marble. All these results correlate with those found in the adjacent area by previous workers and this indicates the same extension of marble in these areas. The Muro marble can be used economically as raw materials for a variety of products such as fillers, glass, papers, lime, pesticide and sewage treatment, decorative construction, monuments, paint making and most of all very suitable for cement production.