Review Of Geological Exploration Of Limestone

ABSTRACT

Limestone, which is known as sedimentary rock composed mainly of calcium carbonate (CaCO₃), usually in the form of calcite or aragonite. It may contain considerable amounts of magnesium carbonate (dolomite) as well; minor constituents also commonly present include clay, iron carbonate, feldspar, pyrite, and quartz. Limestone occurs only in the sedimentary basins in Nigeria. It occurs mainly in the Benue Trough (Lower, Middle and Upper), Sokoto, Dahomey and Borno (Chad) Basins. Limestone-forming environments (shallow coastal marine conditions), appear to have occurred several times in the geological history of the basins. However, the limestone deposits of the Benue Trough (Lower, Middle and Upper), appear to contain the largest and most economically viable limestone resources in the country. Nearly all the limestone deposits in the country are used for the manufacture of cement. Marble, a metamorphosed limestone occurs within the migmatite- gneiss-schist-quartzite complex as relicts of sedimentary carbonate rocks. These are Upper Proterozoic schist belt metasediments which are normally marked by a general absence of carbonates. Such marble deposits appear to be limited to the western portions of the south and central parts of the country. Several of these marble deposits are currently being exploited for cement (Ukpilla and Obajana) and decorative stone (Jakura, Kwakuti and Igbetti) with some production of ground rock for industrial use. Limestone and marble are among the few industrial minerals and rocks that have been utilized to any great extent in the country. This article summarizes the information available on the country’s limestone and marble deposits (the geology, occurrences, characteristics, reserves, production and quality). Recommendations are proposed for developing the limestone and marble industry to make a positive contribution to the national economy.

TABLE OF CONTENTS

COVER PAGE

TITLE PAGE

APPROVAL PAGE

DEDICATION

ACKNOWELDGEMENT

ABSTRACT

CHAPTER ONE

INTRODUCTION

1.1 BACKGROUND OF THE STUDY

• AIM/OBJECTIVE OF THE STUDY
• STUDY AREA

CHAPTER TWO

LITERATURE REVIEW

• REVIEW OF THE STUDY
• CLASSES OF LIMESTONE
• USES OF LIMESTONE
• FORMATION OF LIMESTONE
• LANDSCAPE OF LIMESTONE

CHAPTER THREE

METHODOLOGY

• GEOLOGICAL SETTING
• LIMESTONE FORMATION
• PHYSICAL AND CHEMICAL PROPERTIES

CHAPTER FOUR

RESULT ANALYSIS

4.1   LIMESTONE OCCURRENCES IN NIGERIA

4.2   CEMENT FACTORIES IN NIGERIA

4.3   INDUSTRIAL APPLICATIONS

CHAPTER FIVE

• CONCLUSION
• REFERENCES

CHAPTER ONE

1.0                                                                                INTRODUCTION

1.1                                                                  BACKGROUND OF THE STUDY

According to Serra (2006), limestone is a sedimentary rock composed largely of mineral calcite (CaCO₃), formed by either organic or inorganic processes. Marble is a metamorphic rock composed essentially of calcite (CaCO₃), dolomite [CaMg(CO₃)₂], or a combination of the two, with a fine- to coarse-grained crystalline texture (Serra, 2006). Limestone and marble are carbonate rocks, dominated by the mineral calcite (CaCO₃).

Nigeria is endowed with large deposits of limestone and marble located in all parts of the country. The limestone at Mfamosing, near Calabar, is the largest and the purest deposit in Nigeria. It is about 50 metres thick at the quarry site. West of Calabar, another carbonate body occurs in the subsurface that is 450 metres thick. The Calabar Flank is the main carbonate province in Nigeria with well-developed tropical karsts and caves (Reiljer and Nwajide, 1998). Limestone, the principal raw materials for cement manufacture, are very essential for a rapidly growing nation like Nigeria. These industrial rocks can be said to be already in extensive use in Nigeria. They are used mostly for one purpose – the production of building and constructional materials. Several cement factories have been built by government and even individuals to utilize the limestone and marble deposits in their respective areas. The output of cement from these companies is quite high, though grossly insufficient to cope with the high demand caused by the appreciable rise in domestic construction. The effect of this insufficiency has been cushioned by the establishment of two cement factories by Dangote Cement Company Plc., one is located at Obajana in Kogi State which is the largest cement company in Africa and the third largest in the world with production of 10.25 million tonnes at the rate of about 1000 trucks per day and the other factory at Ibeshe in Ogun State with 6 million tonnes per annum capacity.

Limestone is extremely valuable industrial rock raw materials. Construction and cement manufacturing industries are principal consumers. They are also used in the production of chemicals, fertilizer, abrasives, industrial fillers, ceramics, etc.

Considerable information on the limestone occurrences and resources in Nigeria has accumulated over the years. This study review all available information on the limestone deposits in Nigeria.

1.2                                         OBJECTIVES OF THE STUDY

The main objective of the project was to carry out a review on all available information on the limestone deposits in Nigeria.

1.3                                                         STUDY AREA

The study area extending between latitudes Latitude 6° 29′ 24.00″N, 4° 57′ 0.00″N, 7° 17′ 46.23″N, 5° 52′ 60.00″N , 6° 44′ 17.02″N, 13° 13′ 20.00″N , 9° 53′ 20.81″N, 10° 18′ 35.35″N, 6° 20′ 20.69″N, 5° 43′ 12.00″N, 5° 7′ 0.00″N, 8° 24′ 0.00″N and longitudes 4° 24′ 0.00″E, 8° 19′ 30.00″E, 8° 28′ 53.41″E, 7° 55′ 60.00″E , 7° 0′ 39.57″E, 4° 54′ 42.22″E, 11° 13′ 16.36″E, 9° 50′ 42.62″E, 5° 37′ 35.34″E, 7° 33′ 36.00″E, 7° 22′ 0.00″E, 8° 33′ 0.00″E  falls in Ogun, Cross River, Benue, Ebonyi, Enugu, Sokoto, Gombe, Bauchi, Edo, Imo,  Abia, Nasarawa which are twelve state in Nigeria.