ABSTRACT:The aim of this work is to investigate the effect of waste dumps on the groundwater in Choba using resistivity sounding method and laboratory water sample analysis. An ABEM SAS 1000 terrameter was used to acquire data in two locations namely; at the dumpsite and at University Demonstration Secondary School adjudged to be free from dumps which served as a control. The result of the survey interpreted by 1P12 win and offix softwares shows two characteristic curve types: -Type A curve at the dumpsite and Type H curve at the University Demonstration Secondary School. The result further indicates that the first two layers at the dumpsite has resistivities of 59.91 and 20.10 ohm.m respectively and at the Demonstration Secondary school as 173.00 and 512.00 ohm.m respectively, showing that the groundwater at the dumpsite is polluted because of the high conductivity . This was confirmed by the laboratory water sample analysis from the environ. However, fresh uncontaminated water is got below 23m deep at the two sites. Niger Delta has multi aquifer systems, therefore geophysical survey is essential to locate at least the depth to the third aquifer which hopefully will give portable drinking water free of contamination.

Abstract:The study area (Igarra) has been variously studied and is still receiving attention from workers on basement geology. Some investors in the quarry industry still make error in the selection of site for development and production of crushed rocks and dimension stone. The Octopol quarry in Igarra area was abandoned largely due to scanty information on the mineralogy of the schist quarried to ascertain the quality of the rock. However, granites, granite gneisses, charnockites and marbles present in the area can be suitable for dimension stone production. The marble should not be cleaned with wet cloth as the water will react with the rock to form a weak acid which attacks the polished surface and decolourize it to a dull and uninteresting surface. There is need to involve geoscientists in dimension stone site selection and production to ensure that proper rock is chosen, and also for quality control as mining progress rock quality varies.

The study area Lokoja is the home to the confluence between Rivers Niger and Benue. Dimension stone is cut or quarried stone in accordance with specific dimensions, generally more abundant and are used in greater quantities than ore minerals in pavement and several other constructional activities. The objective of the paper is to present prospects and a lead of rocks in Lokoja area for the production of dimension stone. The rocks in the area are being quarried as aggregates or mined as dimension stone and they met quality parameters of the rocks which includes, must be durable, easy to quarry, work, cut and polish. The particular stones selected depend upon the local weathering conditions which can be determined by amounts of industrial gases present and availability of the rocks locally. The rocks identified are marbles, granite gneisses, migmatites and biotite granites. The granites are being quarried for aggregates, marbles are powdered for cement production while migmatites and granite gneisses were mined for dimension stone.The results of Rock Strength (MPA), Rock Class Factor and Swell Factor are within acceptable standard limits except for migmatites with RS 36%, RCF 7% and SF 1.25%, which is above the limit when compared with previous analysis of AAV 22.0%, ACV23.3%, AIV18%and Absorption 0.54% in Boki area. The dimension stone were separated by more precise and delicate techniques, such as diamond wire saws, diamond belt saws, in the mine the cut dimension stone width are 1m, while many are rectangular in shape. They occur in the same geologic setting of the basement complex of Northcentral Nigeria. In the area investment has been at relatively low stage more investment will significantly increase production of the dimension stone for local usage, export and economic growth. Keywords:Dimension stone, durable, available, maintenance, migmatite, Lokoja

The lead-zinc deposit of Enyigba and its environs are localized in the cretaceous sedimentary rocks of the Albian Asu River Group in the Lower Benue Trough, Southeastern Nigeria. The Albian Asu River Group is made up of shale, siltstone, sandstone and limestone. The deposits were formed epigenetically through the crystallization of hydrothermal solutions and are localized within the fractures, hence the need to study the trend of the fractures in the rock unit where the mineral deposits are being hosted. In order to study the fractures, two units of the formation were identified and designated as units A and B. The ore field extends to about 3.7 km strike length with an average width of 5 m. From the detailed field mapping, the identified structures that control the mineralization are fold, fault and joint/fractures in which the fractures predominate. The total measured identified fractures is 503 in number and are represented in rose diagram, histogram and stereographic net which shows that they trend NW-SE and N-S directions, and dip SW-NE direction.

Some part of the Southern Benue Trough (Afikpo and Anambra Basins) has been mapped to determine the areas of occurrence of industrial minerals and to determine their lateral extent. The result shows that Southern Benue Trough is enriched with mostly industrial minerals of sedimentary and magmatic origin. The magmatism that occurred in the study area and its evolutionary processes led to mineralization of the study area. Interaction of the magma with host rocks gave rise to mineral genesis. The contamination and assimilation processes that occurred in the magmatic stage resulted to enrichment of minerals in the study area. The contact relationship of the magma with the host rock created a contact aureole though the resultant minerals (metamorphic minerals) of the contact aureole are not significant and exposed. The repetitive transgressive-regressive sedimentary cycle that occurred in the Southern Benue Trough probably resulted to the massive deposition of industrial minerals of sedimentary origin. The dominant and significant industrial minerals in Afikpo and Anambra Basins are sandstones (ferruginized sandstone, calcareous sandstones and carbonaceous sandstones), clay mineral (kaolinite), pebbles, igneous rocks of diverse levels of emplacement (intrusive/ extrusive), olivine , hematite, Feldspar, mica and quartz.