Earth Science Research; Vol. 7, No. 1; 2018 ISSN 1927-0542 E-ISSN 1927-0550 Published by Canadian Center of Science and Education 1 Mineralogical and Geochemical Appraisal of Clay Deposits in Papalanto and Its Environs, Southwestern, Nigeria Adewole John Adeola 1 & Modupe Adefunmi Olaleye 1 1 Department of Geology and Mineral Sciences, Crawford University, Igbesa, Ogun State, Nigeria Correspondence: Adewole J. Adeola, Department of Geology and Mineral Sciences, Crawford University, Igbesa, Ogun State, Nigeria. Tel: 2348-03812-0171. E-mail: johnadeola@crawforduniversity.edu.ng Received: July 21, 2017 Accepted: July 25, 2017 Online Published: August 22, 2017 doi:10.5539/esr.v7n1p1 URL: https://doi.org/10.5539/esr.v7n1p1 Abstract Three residual clay occurrences in Papalanto, Ifo, and Imoto areas which belong to the sedimentary basin of southwestern Nigeria were investigated to determine their industrial applications. The samples were pulverized, sieved, digested with mineral acids and characterized. Clay mineralogy was determined using X-ray Diffraction (XRD). Elemental compositions of the clay samples were determined using Inductively Coupled Plasma-Mass Spectrometer (ICP-MS). Grain size distribution data were obtained by conducting grain size analysis in two parts; sieve analysis and sedimentation. Thermal properties, plasticity tests, density measurement, linear shrinkage and water absorption capacity were determined to evaluate their industrial potentials. Chemical Index of Alteration (CIA) was calculated to determine the degree of weathering in the area. The X-ray diffraction results showed that kaolinite is the dominant mineral, while quartz, anatase and hematite are the major non clay minerals. Chemical data showed that the average values of SiO 2 , Al 2 O 3 , and Fe 2 O 3 were 59.46%, 22.16%, and 3.06% respectively constituting 98.3% of the bulk compositions. Papalanto possessed high plasticity and mouldability. Evaluation of the clay thermal characteristics, firing colour, water absorption capacities and shrinkage values showed that the whitish Ifo clay and Papalanto kaolinitic clays could serve as raw materials for ceramics, building bricks, and other structural wares. Kaolin which is the dominant mineral in all the clays can be used for cosmetics, tooth paste, pharmaceutical purposes Keywords: clay, structural wares, ceramics, anatase, building bricks 1. Introduction Clay minerals typically form over long periods of time from the gradual chemical weathering of rocks, usually silicate-bearing, by low concentrations of carbonic acid and other diluted solvents. These solvents, usually acidic, migrate through the weathering rock after leaching through upper weathered layers. In addition to the weathering process, some clay minerals are formed through hydrothermal activity. There are two types of clay deposits: primary and secondary. Primary clays form as residual deposits in soil and remain at the site of formation and secondary clays are clays that have been transported from their original location by water erosion and deposited in a new sedimentary deposit. Clay deposits are typically associated with very low energy depositional environments such as large lakes and marine basins. From prehistoric times, clay has been indispensable in architecture, in industry, and in agriculture. As a building material, it is used in the form of brick, either sun-dried or fired. Clays are also of great industrial importance, e.g., in the manufacture of tile for wall and floor coverings, porcelain, china, and earthenware, pipe for drainage and sewage. Highly absorbent bentonite is much used in foundry work for facing the moulds and preparing the moulding sands for casting metals. The less absorbent bentonite is used chiefly in the oil industry as filtering and deodorizing agents in the refining of petroleum. Clay is a good raw material for paper, ceramics, plastics, and rubber industries. Clays mixed with other materials serve as drilling muds to protect the cutting bit while drilling. Other uses are in the making of fillers, sizings, in purifying sewage. Clays are very useful raw materials from which many domestic and commercial wares can be manufactured (Adeola 2014, Oyinloye 1991, Bolarinwa and Adeola 2017). In Nigeria, clay deposits have not been utilized adequately considering the qualities of this type of industrial mineral that occurs in the country. This may be due to lack of geological information on the