Sedimentology and heavy mineral studies of Ologe Lagoon, South Western Nigeria
Journal of Geology & Geophysics

Journal of Geology & Geophysics
Open Access

ISSN: 2381-8719

+44 20 3868 9735

Sedimentology and heavy mineral studies of Ologe Lagoon, South Western Nigeria

International Conference on Geology

June 22-23, 2015 Florida, USA

Ibitola M P1 and Dublin Green C O2

Posters-Accepted Abstracts: J Geol Geosci

Abstract :

Eighteen bottom sediment samples were analysed for textural characteristics, heavy minerals analysis and provenance study of the Ologe lagoon. The megascopic studies showed the dominant sediments as sand and sandy mud. Pattern of sediment distribution consists of mud in the swallow marginal areas of the river channel while the channel centers are predominantly fine grained sand. The granulometric analysis reveals a fine grained sand of an average graphic mean of 2.22 ?. Sediments were moderately well sorted with an average Inclusive standard deviation of 0.65 ?. Skewness varied from fine skewed to coarse skewed with majority of the sediment samples are near symmetrical. The kurtosis average value is 1.19 ? (leptokurtic). The heavy mineral assemblages within the lagoon show the presence of opaque and non opaque minerals such as Zircon, Tourmaline, Rutile Staurolite and Garnet. The percentage proportion of individual heavy minerals analysed are opaque mineral 45.61%, Rutile 19.78%, Zircon 18.29%, Garnet 8.53% and Staurolite 2.57% respectively. The calculated zircon tourmaline, rutile (ZTR) index in percentage varied between 76-92%, average garnet-zircon index (GZI), rutile-zircon index (RuZI) values in all the stations are 16%, 54%, 25%. The bathymetry reveals an average depth of 3.3 m. The marginal areas and channel centres has a depth of 2.8 m and 8.5 m respectively with high concentration and deposition of heavy minerals at the deep channels. The ZTR index average value of 85% was obtained indicating that the sediments within the lagoon are mineralogically matured. The low value of SZI indicates sediments with a long transportation history. The presence of zircon, rutile and tourmaline indicates an acid igneous rock source of the sediments. However, the presence of staurolite, rutile and garnet occurrence indicates reworked sediments of pre existing rocks (sedimentary and metamorphic rock source).