Physical and Mechanical Characteristics of the Conglomeratic Layer in Akure, Southwestern Nigeria.

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O.A. ADEMESO
B.I. ADEYEMO

Abstract

The highly indurated sedimentary layer in Akure, southwestern Nigeria was investigated for the physical and mechanical properties for the purposes of defining the spread, identify and classify it as well as determine the engineering value. The samples were physically and texturally examined on the field and described accordingly. The Uniaxial Compressive Strength (UCS) was determined with the indirect and direct methods using the Schmidt rebound hammer and the MTS Servo Compressive Tester respectively. ISRM procedures for determining the bulk density, dry density and water absorption were adopted. The immersion method was employed to determining the porosity and moisture content. The physico-mechanical tests results were then used to develop mathematical models. The layer was found to contain clasts embedded in reddish brown matrix. The clasts which are angular to sub-angular are mainly quartzites. Subordinate dark brown ferruginous clasts were found in parts of the study area. The results from the natural moisture content range from 1.32% to 3.88%, the dry density varies from 20.5 to 29.0KN/m3, bulk density ranges from 25.38KN/m3 to 30.38KN/m3, water absorption from 4.36% to 6.58%, porosity values from 11.08% to 18.80%. The Uniaxial Compressive Strength (UCS) value ranges from 32MPa to 69MPa. Correlation between UCS and rebound values gave a coefficient of 0.92. Comparing the UCS with those obtained for associated soils by previous researchers showed the layer having higher values. The layer is therefore classified as clast supported conglomerate and is believed to serve as semi-impervious layer protecting the lower layers of soil and aquifer from erosion and pollution respectively. The preservation of the layer should therefore be of paramount importance to the managers of land and underground resources.


 

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References

References
Journal
ADEMESO, O.A., (2010): Field and Petrographic Relationship Between the Charnockitic and Associated Granitic Rock, Southwestern Nigeria. World Academy of Science, Engineering and Technology, 71 pp 626-630.
OLUWAPELUMI O. OJURI, (2013): Predictive Shear Strength Models for Tropical Lateritic Soils. Journal of Engineering Volume 2013. 8pp. http://dx.doi.org/10.1155/2013/595626
Edited publication
ADEKOYA, J.A., KEHINDE-PHILLIPS, O.O. and ODUKOYA, A.M., (2003): Geological distribution of mineral resources in southwest Nigeria. In: Prospects for investment in mineral resources of Southwestern Nigeria. A. A. Elueze (Ed.) pp 1-13.
Walker R.G. (1978): Facies Models. Reprinted with Revisions from a series of papers in Geoscience Canada, 211pp.
Book
BOGGS, S. (2006): Principles of sedimentology and stratigraphy, 2nd ed. Printice Hall, New York, 662 pp. ISBN 0-13-154728-3
DUZE, M. and OJO, A. (1977): Macmillian Senior Atlas; Macmillian Publishers, London, UK. 135 pp ISBN 534-1-4020-0872-6.
FRIEDMAN G.M. (2003): Classification of Sediments and Sedimentary Rocks. In Gerard V. Middleton, ed., Encyclopedia of Sediments & Sedimentary Rocks, Encyclopedia of Earth Sciences Series. Kluwer Academic Publishers, Boston, Massachussetts 81pp ISBN 978-1-4020-0872-6.
ISRM (1989): Suggested Methods for Rock Characterization Testing and Monitoring ISRM Commission on Testing methods, E. T. Brown Edition. Pergamon Press Oxford 211p
NICHOLAS, G. (2009): Sedimentology and Stratigraphy, 2nd ed. John Wiley & Sons Ltd, Chichester, West Sussex, United Kingdom. 419 pp. ISBN 978-1-4051-9379-5.
OWOYEMI, F.B. (1996): A Geologic/Geophysical Investigation of Rain-Induced Erosional Features in Akure Metropolis. Unpublished M.Sc. Thesis, Federal University of Technology, Akure. pp 11-18.
SEIBOLD, E. & BERGER, W.H. (1996): The Sea Floor: An Introdution to Marine Geology, Springer, 356 pp.


References
Journal
ADEMESO, O.A., (2010): Field and Petrographic Relationship Between the Charnockitic and Associated Granitic Rock, Southwestern Nigeria. World Academy of Science, Engineering and Technology, 71 pp 626-630.
OLUWAPELUMI O. OJURI, (2013): Predictive Shear Strength Models for Tropical Lateritic Soils. Journal of Engineering Volume 2013. 8pp. http://dx.doi.org/10.1155/2013/595626
Edited publication
ADEKOYA, J.A., KEHINDE-PHILLIPS, O.O. and ODUKOYA, A.M., (2003): Geological distribution of mineral resources in southwest Nigeria. In: Prospects for investment in mineral resources of Southwestern Nigeria. A. A. Elueze (Ed.) pp 1-13.
Walker R.G. (1978): Facies Models. Reprinted with Revisions from a series of papers in Geoscience Canada, 211pp.
Book
BOGGS, S. (2006): Principles of sedimentology and stratigraphy, 2nd ed. Printice Hall, New York, 662 pp. ISBN 0-13-154728-3
DUZE, M. and OJO, A. (1977): Macmillian Senior Atlas; Macmillian Publishers, London, UK. 135 pp ISBN 534-1-4020-0872-6.
FRIEDMAN G.M. (2003): Classification of Sediments and Sedimentary Rocks. In Gerard V. Middleton, ed., Encyclopedia of Sediments & Sedimentary Rocks, Encyclopedia of Earth Sciences Series. Kluwer Academic Publishers, Boston, Massachussetts 81pp ISBN 978-1-4020-0872-6.
ISRM (1989): Suggested Methods for Rock Characterization Testing and Monitoring ISRM Commission on Testing methods, E. T. Brown Edition. Pergamon Press Oxford 211p
NICHOLAS, G. (2009): Sedimentology and Stratigraphy, 2nd ed. John Wiley & Sons Ltd, Chichester, West Sussex, United Kingdom. 419 pp. ISBN 978-1-4051-9379-5.
OWOYEMI, F.B. (1996): A Geologic/Geophysical Investigation of Rain-Induced Erosional Features in Akure Metropolis. Unpublished M.Sc. Thesis, Federal University of Technology, Akure. pp 11-18.
SEIBOLD, E. & BERGER, W.H. (1996): The Sea Floor: An Introdution to Marine Geology, Springer, 356 pp.