CHAPTER ONE

   INTRODUCTION GEOLOGICAL MAPPING

This geological fieldwork was carried out in the area of Ugwalawo and its environs in Ofu local government area of Kogi state. At the project area, the outcrops seen are that of sandstone, siltstone, ironstone, clay and shale. The outcrops were logged with the appropriate geologic equipments and the textural description taken. Samples were collected from different outcrops for analysis (sieve analysis, pebble analysis, paleocurrent analysis and palynological, and kerogen typing/analysis).

The study area, Ugwalawo, stratigraphically belongs to the Campano-Maasrichtian aged sediment of Mamu and Ajali Formation (See fig.1.1). The study area lies within Anambra Basin which is one of the inland basins in Nigeria. This inland basin is being studied to check out the hydrocarbon potentials of the area. This work was carried out following the methods below; field study, reconnaissance survey, detailed survey and laboratory analysis. The different data collected in the study area were subjected to laboratory analysis (sieve, pebble, paleocurrent, palynology and kerogen) in order to determine the depositional environment of the area and their results are detailed down in their appropriate chapters.

• Location and Accessibility

The study area is located in Ofu local government area of Kogi State (See fig.1.2). It is headquarter of the local government covering an area of approximately 50sq km and lies between latitude of 7 10’N and 7 20’N and longitudes 6 50’E and 6 55’E.

The towns in the area includes: Ugwolawo, Ugbogbo, Ogboga, Ojete, Atukbu, Allome, Ukpotume, Ofolijinwa, Odah, Oji-ofa, Ogaji, Obagwu, Ugbobala, Ikagbo, Ojuwa omachi. These communities belong to Ofu and Odolu/Igalamella local government area in Kogi state. The area is accessible through major road passing through Idah to Ajaokuta. Other minor roads and footpaths are also used for accessibility (fig.1.3).

• Climate, Weather and Vegetation

The prevailing climate in the study area is known as monsoon climate as well explained in the (fig.1.3) below. The climate is classified as (Am) by the Koppen-Geiger system. The area enjoys both wet and dry seasons. The wet season lasts from April to October with a short break in the middle of August tagged (August break). The dry season lasts from November to March. The total annual rainfall ranges from 1000mm to 1500mm. The average temperature is 26.8C and relative humidity of 30% in dry season and 70% in the wet season. Average daily wind speed is 89.9km/hr and usually at its peak in March and April. Average daily vapor pressure is 26Hpa.  About 747mm of precipitation fall annually. The study area lies within the Guinea savana forest belt of Nigeria (fig.1.4).

1.3 Topography and Drainage

The geomorphologic evolution of the area is influenced predominantly by sedimentary terrain. The prominent topographic features in the area consist of an undulating topography occupied by sandstone and lowlands by shale. The highest part of the study area lies in the Northwest with height of 271m above sea level. Other parts of the study area consist of lowlands lying beneath 100m above sea level. The relief and topography as well as rock types (fig.1.5) control the drainage system of the study area. The Aji River and Ola Ofu River constitutes the main drainage system in the area forming dendritic drainage pattern (fig.1.6). The Ofu River sources its water from somewhere north-west of the study area and flows southeast.

1.4 Aims and Objective of Study

The aim of the study is to carry out a detailed geological mapping of the study area and an integrated study of the lithofacies, sedimentary structures, with an attempt in reconstructing the geologic history and paleodepositional environments and to produce a new and updated geological map of the study area.

• People of the Study Area.

Ugwolawo is a town located in the present day Kogi State of Nigeria. The tribe whose basic occupations are subsistence farming primarily populates it. It is regarded as the traditional capital (headquarter) of the Ofu local government area of Kogi State. The predominant language in the area is Igala. The area has a landmass of approximately 50sqkm.

The area has churches such as the CEFN (Christian Evangelical Fellowship of Nigeria), schools (secondary and primary) with Federal Polytechnic Idah (FPI), as the major tertiary institution closest to the study area. They are very hardworking especially their woman who involve themselves in quarrying of rock and farming.