ABSTRACT
The properties of rocks varies from one geological location to another or even disappears laterally and this properties are important factors in the determination of groundwater quantity. This make this research work focused on the Correlative analysis of lithologies and borehole logs in the Basement terrain of Ibadan ,Southwestern Nigeria which falls between Longitude 3° 45̍ 00̎ – 4° 3̍ 00̎ to Latitude 7° 18̍ 36̎ – 7° 34̍ 12̎ using the Borehole logging and Geophysical Electrical Method.
A total of Twenty-two (22) Vertical Electrical Sounding Station and Borehole Log were acquired within the Study area with maximum schlumberger electrode separation of 100m. The data were presented as VES curves interpreted quantitatively by computer iteration using the WinResist Software to obtain the first order geoelectric model parameters. The results of the geoelectric investigation revealed some lithological Layer such as Clay, Laterite, topsoil, Weathered Basement, Fresh Basement.
The interpretation of the result shows that Water is struck between depth of 10m to 65m except at a Location where no water was encountered, the depth from the surface to basement within the study area ranges from 3m to 35m,the calculated Longitudinal Conductance (CL) ranges from 0.02 to 0.60, the Porosity Value is between 4.4% to 52.79%, Permeability Value ranges from 1.78 x 10-10 m/s to 2.6 x 10-3m/s and the Value of Formation Factor (F) ranges from 15.45 to 2786.89.
It can be concluded from the analyzed result that the Correlation between the Electrical Resistivity and Borehole Log shows a fair Correlation Strength and hence further logging techniques such as gamma ray, spontaneous potential should be employ to complement the work.
TABLE OF CONTENTS
CHAPTER ONE
1.0 Introduction
1.1 General statement
1.2 Aim and Objectives
1.5 Review of previous work
CHAPTER TWO
2.0 Geologic setting
2.1 Regional geology
2.1.1 The basement complex
2.1.1.1 Migmatite-gneiss-quartz complex
2.1.1.2 Schist Belt
2.1.1.3 Charnokitic, Gabbroic and Dioritic rocks
2.1.1.4 Older granites
2.2 Evolution and geochronology
2.3 Geology of south western Nigeria
2.3 Geology of the study area
CHAPTER THREE
3.0 Methodology
3.1 Field procedures
3.2 Collection of data
3.3 Methodology for schlumberger
3.3.1 Electrode Separation and Instrumentation
3.3.2 Treatment of Data
3.3.3 Summary of field precautions
3.3.4 Theoretical Background
3.3.5 Interpretation of Resistivity Soundings
3.3.5.1 One-dimensional interpretation
3.3.5.2 Auxiliary point Method
3.3.5.3 Inversion method
3.3.6 Instrumentation
CHAPTER FOUR Result and discussion
4.1 Resistivity and layers 4.2 Correlation of Borehole Log with Resistivity Data
4.3 Correlation of resistivity geoelectric setion
4.3.1 Interpretation of transverse one (1)
4.3.2 Interpretation of transverse two (2)
4.3.3 Interpretation of transverse three (3)
4.3.3 Interpretation of transverse four (4)
4.3.4 Interpretation of transverse five (5)
4.3.5 Interpretation of transverse six (6)
4.3.6 Interpretation of transverse seven (7)
4.4 Correlation of borehole log
4.4.1 Transverse 1
4.4.2 Trasverse 2
4.4.3 Trasverse 3
4.4.4 Transverse 4
4.4.5 Transverse 5
4.4.6 Transverse 6
4.4.7 Transverse 7
4.5 Electrical borehole logging
4.5.1 About true resistivity of formation Rt and formation resistivityy factor F
4.5.2 Relation between CL and F
4.6 Depth to basement
4.7 Depth to water strick
4.8 Porosity
4.9 Permeability
CHAPTER FIVE
5.0 Summary
5.1 Conclusion
5.2 Recommendation
REFRENCES
