GEOLOGY AND GEOCHEMISTRY OF IGBEAGU, IZZI AREA SOUTH EASTERN NIGERIA

CHAPTER ONE

INTRODUCTION

1 GENERAL INTRODUCTION

This project work is based on Igbeagu and its environs,Izzi area in the southern eastern trough of Nigeria. It is part of the Southeastern trough of Nigeria under Asu-Rivers group, Abakaliki formation. The outcrops are mainly Asu-River shales and leadzinc mineralization deposit. It covers some parts of Igbeagu villages such as Ndiachi, Nchoko and Ndiokpoto and boundary villages in Amachi community, such as Ndiudara, Uburu-amachi, Uwarem and Okpitumo. The studied areas are in the North of Abakaliki province mainly Izzi and Abakaliki Local Government Area of Ebonyi State, Nigeria.

The study was carried out to know the geology and geochemistry of some detrimental elements of the mineral resources and to determine the tectonic structures of the area and attempt their analysis and interpretation and obtain detailed structural information on the area of study.

1.1 LOCATION AND ACCESSIBILITY

The area,Igbeagu and it environs is geographically located in Izzi Local Government Area of Ebonyi State in Southeastern part of Nigeria.The co-ordinate of the study area fall within Latitude 6⁰15 AND 6⁰20 and Longitude 8⁰10 and 8⁰15 respectively.

The area can be acess through a major tarred roads,Abakaliki-Ogoja road which runs through Igbeagu to Cross River State,Obuche/Okputumo road and Uburu-Amachi /Uwarem roads in Abakaliki Local Government area.The outcrops are been found along several footpaths leading to the locations.

1.2 AIMS AND OBJECTIVES

This work aimed at knowing the detailed geologic studies and the chemical elements that constitute the geochemistry of the area.

The objectives of the project works are the following:To

(a) The study the geology of the area .(b) know the descriptions of the different rock types seen at the area (c) know the geologic structural evolution of the southeastern trough with respect to rock deformation (d) know the detrimental chemical elements that constitute the geochemistry of the area.(e) Know the azimuths of the tectonic structures such as joints and faults.

1.4 PHYSIOGRAPHY AND GEOMORPHOLOGY

1.4.1 CLIMATE

The climate of the study area is a dynamic climate.It changes with seasons; rainy and dry seasons are the two main seasons conspicuous in the area of study.It has mean monthly temperature in the hottest period of February to April of about 33⁰c and annual rainfall of 152cm³ to303cm³.Rainfall is not all year round.The rainy season is between May and October annually.Dry seasons commence from November with dusty and warm harmattan which last to February the following year.

1.4.2 VEGETATION

The study area is part of the rainforest Savannah belts of Southeastern Nigeria.The forest is dense or thick and characterised with creepers and climbers.The forests are ever green in the area at any time of the year mostly with green leaves.The forests are characterised by stunted trees and pockets of derelicts woodland and secondary forest consisting of few shrubs with dispersed large trees.The tropical rainforest vegetation,there are competition for sunlight which accounts for the tallness of the three and the profusion of climbers and other parasitic and epiphytic plants.

1.4.3 DRAINAGE

Drainage is the natural or artificial removal of surface and sub-surface water from an area. The drainage patterns are dependent on vegetation,relief,soil type,topography and some other physiography and geomorphology of the study area.The drainage of Ebonyi State is controlled by Cross River which form the tributary of Cross River.The flow pattern recorded there are that of irregular dendritic partern consisting of a number of small emphemeral streams and the tidal pattern found at the Ebonyi River and some trellised pattern at most of the stream.

1.4.4 RELIEF

The research area and Ebonyi State in general lies area of moderate relief ranging between 125 and 250m above sea level.The highest part of the state is around Afikpo with elevation of 170m above sea level.The topography of the area is characterised with undulating plains with irregular ridges,gentle sloping hills and valley.The topography of the area is controlled by the bedrock geology defined by by the area of high erosion,capped by the lowlands.

1.4.5

SOIL AND EROSION

There are mainly two types of soil found in Ebonyi State and the studied area.These soil types are the silt clayey soil and clayey lateritic soil.Silty clayey hydromorphic soil has a brown loamy top horizon overlain by reddish brown silty clayey subsoil.The clayey lateritic soil act as an overburden mainly laterite for refilling. There are moderately to imperfectly drained,with moderately low natural fertility.The clayey lateritic soil occurs mainly in low lying areas of land.The poor fertility of the soil are as a result of strong acidity and lack of nutrient and they suffer from poor drainage.The soil are most suitable for Cassava planting,yam cultivation and loamy clayey for rice cultivation.The erosion are mainly sheet and gully erosion.The soil is drained with the help of eroded parts leading to theb different streams in the study area.

1.4.6 LITERATURE REVIEW OF THE LOWER BENUE TROUGH

The mapped area has no locally documented work done on the aspect of geological investigations and geochemical sampling.Moreover,on a regional scale,a lot of work have been done and documented.Notably among them are:Obaje(1979),Farington(1952),Reyment(1965),Murat(1979),Simpson(1954),Grant(1971), Kogbe(1979),Olade(1979),Ojob(1992),and Petter(1982).

According to Grant(1971),the Abakaliki and Benue trough contain folded and unfolded cretaceous sediment deposited during two Mesozoic,Failed Arms or Rift Tripple Junction.The benue Arm also formed the third arm of Chum Trilete Junction(rrr) consisting 0f the Benue,Yola,and Gongola arm.

The santonia tectonic phase resulted to fracturing and folding in the area,giving rise to series of anticlines known as ‘Abakaliki Anticlinorium’Reyment(1965).Sedimentation in the lower benue trough commenced with Marine Albian Asu-River Group with some eruptions of pyroclastic of Aptian-Early Albian ages(Ojob,1992).The sediment Asu-River Group have been estimated to be between 1900m and 300m thick and the Cenomanian formation resting directly on Pre-cambrain basement rocks about 1000m thickness of its deposits(Reyment,1965,and Dessauvagie,1970).There were deposited under shallow water conditions.The Asu-River Group sediments are associated also saline seepages,lead zinc mineralization basic intrusions and Pyroclasti (Agumanu,1989).Onthe region,the Asu-River Group in the lower Benue trough comprises of the shales,limestones and sandstone lenses of the Abakaliki formation in the Abakaliki area and theMfamosing limestone in the Clabar Flank(Petters,1982).The Abakaliki shales of the Asu-River Group hosts shales(Reyment,1965).(Reyment,1965)also described the lithostratigraphy and biostratigraphy of the Asu-River.During the Cenomanian,mostly continental conditions existed and was terminated by a marine transgression at the beginning of the Turonian.The sea penetrated the interior of the country from the Gulf Guinea as far as the Benue valley(Reyment,1965).The marine Cenomanian to Turonian formation comprises mainly shales ,limestone and siltstone(Obaje,2009).

During the Coniaacian,beds of rapidly changing lithofacies including shales,limestones and increasing amount of shales were deposited in southeastern Nigeria,the Nkporo and its lateral equivalent to the Enugu shale Owelli sandstone constitute the basal beds of the Campanian which began with short marine transgression followed by regression(Reyment,1965).The regional study pre-santonian sediments about more than1500ft were drposited in various parts of the Benue troughs.Parts of these sediments are lead-zinc mineralization and metamorphosed shales in the Abakaliki fold belts.The study Schannel due to its lateritic overburdens.There are no much petrologically works but mainly conglomerate and ironstone.

According to Farrington (1952),explain the trends directions of the the major joint directions are in the NW/NNW,SE/SSE but mainly NE-SW in the lower Benue trough.

CHAPTER TWO

REGIONAL GEOLOGY OF LOWER BENUE TROUGH

2.1 REGIONAL TECTONIC SETTING OF THE LOWER BENUE TROUGH

The rift origin (Benue trough),Kogbe(1976),supported by many other authors(Kenneddy,1965;Stonely,1966,Wright 1968,McConnell1969,Hosper 1971,Grant 1971,Murat 1972) was generated in the ‘plate Tectonic’ concept andin the year 1970,several models were proposed to explain the originof Benue Trough.

In the first models proposed(Burke etbal,1970;Burke etnal 1971)the Benue Trough is compared to existing similar structure(Afar).In such RRR triple Junction,it was suggested that a new oceanic crust was generated beneath the Abakaliki trough.Since 1980,the models proposed for the evaluation of the benue Trough are based rather on field geology and structure analysis than on plate tectonic considerations(Benkhelil andRobineau,1983).

The structura framework of the lower Benue troughincludes two main units:The Anambra syncline and the Abakaliki anticlinorum.The Anambra syncline is a vast sedimentary basin trending northeast-southwest for more than 200km,from the NigerDelta hinge to the Gboko area.The core of the anticlinorium is occupied by the oldest sediment known in this part of the Benue Trough,the shales of the Asu-River Group of Albian age.

2.2 REGIONAL STRATIGRAPHIC SETTING OF THE LOWER BENUE TROUGH

The study area are within the southern Benue Trough and its stratigraphic sequence as given by Reyment(1965) is from the Albian to Pliocene.The loewer Benue trough ‘Abakaliki formation’stratigraphic sequence started from Albian to Santonian.

2.2.1 ALBIAN

The oldest sediment in the Southern Nigeria is around Abakaliki in Southeastern Nigeria. These are unnamed and undifferentiated.They constitute the ‘’Asu-River Group’’,the area of the group is along Asu-River (Reyment,1965).The sediment consist of ratherly poorly bedded sandy shales known as the Abakaliki shales with sandstones and and sandy limestone lenses.The limestone beds can attain a thickness of 30m.Paleontologically,the shale is mainly characterised by species of Mortoniceras and Elobiceras.The shales are deeply weathered and contain Radiolaria,Echinoids and some pelecypods and Gastopods.Sediment of Asu-River group are folded particularly in the south of Abakaliki and the folded axes stretch NE-SW (Reyment,1965).These beds have recorded to be associated with lead- zinc mineralization.

2.2.2 CENOMANIAN

The bed of Cenomanian age is restricted to the Odukpani formation of the southeastern corner of the Nigeria Coastal Basin around Calabar,though Cenomanian age has been assigned to Muri sandstone in the middle Benue region(McConnell,1949).The deposits consist of arkosic sandstone,limestone and alternating limestones and shales which become gradually more predorminantly shally in its uppermost parts(Reyment,1965).The sediment are of shallow marine origin.The type locality is at Odukpani village near Calabar(Kogbe,1989).Nwachukwu(1972) suggested a possible slight tectonic movement in the Southern portion of Benue trough during theCenomanian.

2.2.3 TURONIAN

The Turonian deposits mainly belong to the Eze-Aku formation(Eze-Aku shales,Simpson,1955) deposited in thesecond transgressive phase in Nigeria.The type locality is the Eze-Aku river valley in Southerneastern Nigeria.The formation consists of hard grey to black shales and siltstones with frequent facies changes to sandstone or sandyshales.Thickness varies but may attain 100m in places(Reyment,1964).The Eze-Aku sandstone bulk textural character comprises a coarsering upward grain size gradient which ranges from fine to vary coarse sandstone.Locally, at Amasiri,the Eze-Aku formation passes laterally into the ‘’Amasiri sandstone’’ facies.The Eze-Aku formation is structurally deformed by the Santonian tectonic event(Nwachukwu,1972,Amajor,1985).The Eze-Aku formation is of shallow water deposit.The fossil consist mainly of Vascocoratids,Pelecypods,Gastropods,Echinoids,Fish teeth,which indicate a basal Turonian age(Kogbe,1989).

2.2.4 CONIACIAN-SANTONIAN

Sediments of Coniacian-Santonian age are generally less thick than Turonian and they tend to give impression of rather lateral changes in facies(Kogbe.1989).The sediment have been assigned to Awgwu formation(Awgwu shale of Reyment,1965).The formation is about 800m thick and consists of marine fossilferous grey-blue shales associated with sub-ordinate limestone and calcerous sandstone.The Santonian age is a regressive substage in Nigeria and sediments of this age have not been found in Southern Nigeria(Kogbe,1989).A doubtful Santonian locality in the Awgwu shale in Igumale area has yielded Ostracods possibly referable to this substage(Reyment,1960).

2.2.5 CAMPANIAN-MAASTRICTHTIAN

The Nkporo shale and its lateral equivalent,the Enugu shale and Owerri sandstone constitute the basal beds of the Campanian in Southeastern Nigeria.The short marine transgression followed by a regression deposited the Mamu-formation(Kogbe,1976).The Mamu formation(Lower coal measures) consists carbonaceous shales,siltstones,coal and sandstone(Simpson,1955).This formation was overlain by the Ajali formation followed by a return to partially paralic condition with the deposition of Nsukka formation(Kogbe,1976).

Table 1: Regional Stratigraphic sequence of southeastern Nigeria classified by (Reyment, 1965.Murat, 1970 and Hogue, 1977).

Age(Ma)		Abakaliki-Anambra Basin	Afikpo Basin
33.7	Oligocene	Ogwashi-Asaba formation	Ogwashi-Asaba formation
548	Eocene	Ameki-Nnanka formation,Nsugbe sandstone	Ameki formation
65.0	Paieocene	Imo formation Nsukka	Imo formation Nsukka formation
72.0	Maastrichtian	Ajali formation Mamu formation	Ajali formation Mamu formation
83	Campanian Santonian Coniacian	Nkporo,Owelli formation Enugu shale Agani sandstone	Nkporo Afikpo sandstone
94.0 99.0 112.2	Turonian Cenomanian Albian	Eze-Aku Group Asu-River Group	Eze-Aku Group (Amasiri sandstone)
121.0	Aptian
127.o	Barrenmian	Un-named units	Asu-River Group
132.7	Hauterive
Precambrain		Basement	Complex

CHAPTER THREE

GEOLOGY OF THE AREA

3.1 General Geology of the Study Area.

The mapped area is part of the southeastern Benue trough. They belong to Asu-River under Abakaliki formation and are within the oldest sedimentary unit of the south-eastern Nigeria.As a result, the area has to be treated in view of the processes that gave rise to the development of the sediments in this group.The sedimentary basin of southeastern Nigeria originated in early Cretaceous Aptian and Albian period shaped depression oriented NE-SW.This depression formed on the Basement complex was predetermined by the structural conditions established in 600Ma.Pan-African thermo tectonic episode (kennedy 1965).Marine transgression occurred in Albian resulting in depression of sediment within the geosynclinals trough shales were primarily deposited siltstone, sandstone and limestone. Mainly,marine shales were deposited on both shallow and deep water, limestoneand siltstones were deposited at the margin of the marine embayment during the transgressive phase sandstone were derived from the shelf areas and up valleys were laid down during the regressive phase.

Regression and intense folding of sediments followed withdrawing of Albian era.Marine sedimentation continued into Cenonian as a result extensive Turonian transgression.Eze-Aku shales with their lateral equivalent, the Amasiri sandstone were deposited. The erosion bared the of Asu-river group .the coal facies of Enugu area were laid.Anambra Basin and Afikpo syncline became the major depositional centre,Reyment(1955),with the help of the occurrence of different genera of ammonites, tried to correlate the various lithological units of Asu-river group.

In the mapped area,the Asu-river groupsediments were ecountered by shales,mudstone and ironstone.The above mentioned sediments belong to the upper Albian in age.The shales are laminated,presencs of joints with fractures and fault and their various trens are NE-SW direction.

3.2 LITHOLOGIC DESCRIPTIONS

The rock type seen at the studied areas are mainly sedimentary rocks.The rocks are shales that are both consolidated and unconsolidated in nature, mudstone and ironstone. The analysis of the trends ‘azimuths of the bedding planes show that the directions is mainly Northwest while the analysis of joints and veins contain quartz and dominantly in NE-SW directions.

3.2.1 Shales

The Asu-River Group underlying the researched area is dark grey, black and reddish brown shales along the river channels though the vertical extension cannot be estimated due to the thickness of overburden the covered the outcrop and also as a result of no available literature review. The lithologys are characterised by extensive weathering on the surface. The weathered surface made them to be poorly laminated, change its colour to be reddish brown and lack prominent fissility.The units have some joints while some are unjointed.The thick of the outcrop is about 5meter ifmeasured.The dark grey shales are seen at Ndiechi Onuebonyi,ndi-ogbu,Amuzu at Igbeagu and Egwuagu at Okputumo.There are presence of fissility shales at the top base but in between them is very consolidated dark shales which continuously laterally within the bed.Th shales are well laminated,fissile,and jointed but not in all locations.The ironstone seen is siltstone at Okputumo(Egwuagu),its occurrence is laterally shown at the surface but along sides are shales.The shales are highly consolidated and unconsolidated in some layers with fragile once at the weathered parts. They are the major rocks found at mapped areas. Mudstone overlies some shales’unitsand lithofication and compaction take place. The general trends of the beds are in the NE-SW direction corresponding to that of Asu-River.

3.2.2 Unit A (dark-Grey shale)

The shales are dark to grey colour fine-grained with some darker patches and more consolidated the unit B shales.They are jointed with its trends of NE-SW direction.The are laminated,bedded with presence of faults, all in the same direction while the directions are NW OF THE Benue trough. The thickness of the consolidated dark to grey shales are 30m in first layer ,30m in the third layer,15m in the fouth layer,150m in the sixth layer. Thereare presences of metamorphosed shales known as baked shales at Okputumo.

3.2.3 Unit B (Olive Brown shales)

The shales are Brown in colour, it is highly fissile and friable.Tere are a lots of Laminations but mainly weathered. The colour come as a result of its contact with water and other organic matters .The beds attitude are in NE-SW direction. The shales are found at Ebonyi river,Ndiogbu,Nchoko,Amuzu,Uburu-Amachi and Okputumo.

3.2.4 Mudstone

The unit occur at the topmost sediment in the study area. They are overlain by the Lateritic overburden.There is no lamination bedding planes. The mapped area found at Erigba dam Ndiechi Onuebonyi.The dam here has an internal drainage and it’s a seasonal dam which are being sustain by the mud cracks.

3.2.5 Ironstone

These units are interbedded with shales and occur as vein fillings and ironstone shale interbeds.The units are known to have been as a result of the transformation of shales along the path of hydrothermal fluids in the study areas. Thetextures are fine to medium grained ,with a characteristic reddish brown colouration which is yellowish brown colour along weathered surfaces and reddish brown ironstone are sideritic are Sideritic.They are limited in extent and massive in some areas like Amuzu,Nchoko and Egwuagu-Okputumo.The are majorly used in construction.

3.3 SEDIMENTARY STRUCTURES

Sedimentary structures are physical features on sedimentary rock that could give information on the geological processes that have taken place on the rocks. The term sedimentary structure can be described as any physical, chemical or biogenic features formed in sediment either contemporaneous with or subsequent to deposition. The sedimentary structures are important attribute to sedimentary rocks. The sedimentary structures are divided into syn-genetic and post-genetic structures depending on when the structures were formed with respect to their host rock while post-genetic structures formed after the rock had formed.

3.3.1 SYN-GENETIC SEDIMENTARY STRUCTURES

These comprise physical stratification structures which include lamination and bedding planes as Potter et al (1980) divided it. Physical sedimentary structures are often employed as a guide for identifying agents and environment of deposition. Cross bed data provide valuable information in mapping palaeocurrents (Pettijohn, 1975).

3.3.1.1LAMINATION AND FISSILITY

The light-dark grey shales show parallel laminations. Parallel laminations may be as a result of the alteration of silt-rich and clay rich laminea and variation in the rate of supply of materials and also deposition of materials of contrasting characters. Laminations are usually less than one centimetre (1 cm). There are two type of lamination in the map area, namely even lamination and lamination consist of alternating light and dark layers. Even laminations describe shales that exhibit fissility. This type of lamination was seen at Ebonyi River and Uburu-Amachi Bridge. Even laminations result in sedimentation from suspension in a low energy environment.

The shales show prominent fissility which occurs when the shales split along a horizontal surface parallel to the bedding plane as a result of parallel arrangement of clay minerals, mica and other minerals. Fissility was observed on the dark-grey shales seen in some part of the study area like Ebonyi River and under Uburu-amachi Bridge.

3.3.1.2 BEDDING PLANES

Bedding planes are geological term which refers to the existence of sediments in beds or layers ranging in variable thickness.There are also known as stratification. Continuous distinct prominent parallel beds suggest deposition under minimum energy and tectonically dormant environment. Incline bedding of varied angle anddirections of dips are indicative of great tectonic in the past geologic history. The readings of bedding planes measured in the study area are shown in the table below

Table 2: Measurements of the bedding planes

Locations	Bedding trends	Dip Amount	Dip directions
Ebonyi river,Ndiechi	N60- N240	15	N105- N285
Ogbuenyanwu(Ebonyi river)	N70-N250	11	N95-N275
Between Ndi-ogbu and Ndi-igwe river	N60-N240	38	N54-N235
Kperekpere,Amuzu	N50-N230	24	N45-N225
Between Ndi-ogbu and Ndidoko river channel	N60-N240	30	N135-N315
Beside Assembly Of God, Amuzu	N60-N240	12	N 30-N120
Uburu-Amachi bridge	N80-N260	23	N98-N278
Egwuagu stream,Okputumo	N85-N265	18	N155-N335
Ndiudara,Amachi	N65-N245	20	N100-N280

Table 3: Frequency table of bedding planes measured in the study area

Class interval(⁰)	Correspondence interval(⁰)	Frequency	Percentage (%)
0-30	181-210	0	0
31-60	211-240	4	40
61-90	241-270	6	60
91-120	271-300	0	0
121-150	301-330	0	0
151-180	331-360	0	0
Total		10	100

3.4 POST-GENIC SEDIMENTARY STRUCTURES

Post genic sedimentary structures are those structures that are formed after sedimentation of sedimentary rocks. There are mainly biogenic structures or chemical structures. The structures came as a result of activities living organisms (biological activities) on the sediments. The post- genetic structures are potholes,bioturbations,burrows,toolmarks,concretions,and mud cracks. These sedimentary structures depend on the type of sedimentary rocks found. There are mostly found in areas of shales, sandstone and limestone depositions. On the mapped area are found the burrows,potholes,concretion and mud cracks.

3.4.1 BIOGENIC SEDIMENTAREY STRUCTURES

These are features associated with activities of living organisms in the sediments.There are evidence of organic of life in response to ecologic factors such as water depth,salinity,waves and current level,substrate characters,sedimentation and oxygen levels.The onlybiogenic structure present in the study area is burrow and are restricted to the siltstone-shale facies.

3.4.1.1 BURROW

This is one of the biogenic structure found mainly in siltstone,shale,sandstone and limestone depositions. Burrows are developed after deposition as a result of records of living organisms present in the past. The once seen in the study areas and show that living organisms inhabit there in the past. Burrows are seen at kperekpere-Amuzu and Egwuagu,Okputumo areas. There are here in shales and siltstones.

3.4.2 CHEMICAL STRUCTURES

Chemical structures are those structures that exist as a result of chemical weathering in the sedimentary rocks. The chemical structure may be as a result of the contact of water with the existingrocks. The chemical structures found in the study areas are potholes and concretions.

3.4.2.1 POTHOLES

Potholes are seen in consolidated shale lithofacies.The potholes are as a result of differential chemical weathering.

3.4.2.2 CONCRETIONS

These are discrete segregation or nodules of common sedimentary material found in shales, sandstone and as well as limestone. Concretions can form at the same time with sediment, enclosing sediments irregular vary in size from few(mm) to few (m) in diameter. Concretions are noticed in Ebonyi River,Kperekpere-Amuzu,Uburu-Amachi and Egwuagu- Okputumo areas.

3.4.5 MUD CRACKS

Mud cracks are those sedimentary found on areas of sedimentary rocks and also one of the secondary or post-genic sedimentary structures. Thecracks develop on mud surfaces due to effect of intermediate exposure and covering by water such as flood plain. There are common to shallow environments and the coverings are generated due t0 shrinkage of sediments. Mud cracks are seen at Erigba- Ndiechi, Onuebonyi and they are very fine-grained silt.

3.5 TECTONIC STRUCTURES

Tectonic structures are those structure produced as a result oftectonic forces acting on the earth crust. The tectonic structures are found in the shale units of the area. Tectonic structures are observed there are joints, faults and fractures.

3.5.1 JOINTS

These are tectonic structures are referred as fractures or cracks in the bed rock essentially with no significant displacement. Joints were observed at Ebonyi River,Ogbuenyanwu(Ebonyi River),Uburu-Amachi bridge.Here,nearly every rock is cut by a variety of fractures, along which there has been particularly no movement, other than that needed to open up the fracture which are known as joints. Joint s is horizontal or vertical joints depending on the directions of the compressive stress during their formations. The joints are numerous and they forms depending on when the structures were formed with respect to their host rock while post-genic structures formed after the rock had formed.

Table 4: Trends of joints measured in the study area

Joint Locations	Trends of Joints
Ebonyi river,Ndiechi	N650-N340⁰,N68⁰-N240⁰,N60⁰-N240⁰,N65⁰-N245⁰,N46⁰-N226⁰,N50⁰-N230⁰,N48⁰-N228⁰,N57⁰-N237⁰,N75⁰-N255⁰,N40⁰-N220⁰,N45⁰-N225⁰, and N50⁰-N230⁰
Ogbuenyanwu(Ebonyi river)	N40⁰-N220⁰,N140⁰-N320⁰,N145⁰-N325⁰,N70⁰-250⁰,N135⁰-N315⁰,N120⁰-N300⁰,N138⁰-N318⁰,N145⁰-N325⁰,N125⁰-N305⁰,N115⁰-N295⁰,N160⁰-N340⁰,N124⁰-304⁰,N110⁰-290⁰,N45⁰-N225⁰,N50⁰-N225⁰ and N33⁰-N213⁰
Between Ndi-ogbu and Ndi-igwe stream channel,Igbeagu	N60⁰-N240⁰,N70⁰-N250⁰,N75⁰-N255⁰,N85⁰-N265⁰,N120⁰-N300⁰,N80⁰-N260⁰,N130⁰-N310⁰,N89⁰-N269⁰,N135⁰-N315⁰,N145⁰-N325⁰,N50⁰-N230⁰,N74⁰-N254⁰,N81⁰-N261⁰,N72⁰-N252⁰ and N73⁰-N253⁰
Kperekpere,Amuzu	N56⁰-N236⁰,N60⁰-N240⁰,N30⁰-N210⁰,N33⁰-N213⁰,N55⁰-N235⁰,N54⁰-N234⁰,N28⁰-N208⁰,N76⁰-256⁰,N65⁰-N245⁰,N40⁰-N220⁰,N120⁰-N300⁰,N90⁰-N270⁰,N50⁰-N230⁰,N85⁰-N265⁰,N72⁰-N252⁰,N95⁰-N275⁰,N53⁰-N233⁰,N88⁰-N268⁰,N92⁰-N272⁰,N115⁰-N295⁰,15⁰-N195⁰,N31⁰-N211⁰ and N65⁰-N245⁰
Between Ndi-ogbu and Ndidoko river channel	N35⁰-N215⁰,N70⁰-N250⁰,N75⁰-N255⁰,N65⁰-N245⁰,N80⁰-N260⁰,N55⁰-N235⁰,N75⁰-N255⁰,N77⁰-N257⁰,N45⁰-N225⁰,N35⁰-N215⁰,N80⁰-N260⁰, and N45⁰-N225⁰
Beside Assembly Of God, Amuzu	N40⁰-N220⁰,N55⁰-N235⁰,N75⁰-N255⁰,N80⁰-N260⁰,N40⁰-N220⁰,N70⁰-N250⁰,N30⁰-N210⁰,N48⁰-N228⁰,N120⁰-N300⁰,N135⁰-N315⁰,andN20⁰-N200⁰
Uburu-Amachi bridge	N45⁰-N225⁰,N50⁰-N230⁰,N48⁰-N228⁰,N60⁰-N240⁰,N65⁰-N245⁰,N68⁰-N268⁰,N70⁰-N250⁰,N78⁰-N258⁰,N80⁰-N260⁰,and N85⁰-N265⁰
Egwuagu stream,Okputumo	N40⁰- N220⁰, N58⁰- N238⁰, N50⁰- N230⁰, N48⁰- N228⁰, N60⁰- N240⁰, N64⁰- N244⁰, N80⁰- N260⁰, N70⁰- N250⁰, N30⁰- N210⁰, N38⁰- N218⁰, N30⁰- N210⁰, N65⁰- N245⁰, N20⁰- N200⁰,and N75⁰- N255⁰
Ndiudara,Amachi	N65⁰- N245⁰, N62⁰- N242⁰, N92⁰- N272⁰, N55⁰- N235⁰, N70⁰- N250⁰, N20⁰- N200⁰, N93⁰- N273⁰, N55⁰- N235⁰, N70⁰- N250⁰, N62⁰- N242⁰, N45⁰- N225⁰, N25⁰-205⁰, N18⁰- N198⁰, N55⁰- N235⁰, N85⁰- N265⁰, N45⁰- N225⁰, N86⁰- N266⁰, N75⁰- N255⁰, N35⁰- N215⁰ and N65⁰- N245⁰

Table 5: Frequency table for joints observed at Ebonyi river, Ndiechi-Onuebonyi,Izzi

Class interval(⁰)	Correspondence interval(⁰)	Frequency	Percentage (%)
0-30	181-210	2	9.1
31-60	211-240	10	45.5
61-90	241-270	7	31.8
91-120	271-300	3	13.6
121-150	301-330	0	0
151-180	331-360	0	0
Total		21

Table 6: Frequency table for joints observed at Egwuagu stream, Okputumo

Class interval(⁰)	Correspondence interval(⁰)	Frequency	Percentage (%)
0-30	181-210	3	21.4
31-60	211-240	6	42.9
61-90	241-270	5	35.7
91-120	271-300	0	0
121-150	301-330	0	0
151-180	331-360	0	0
Total		14

Table 7: Frequency table for joints observed at Ndiudara stream, Amachi

Class interval(⁰)	Correspondence interval(⁰)	Frequency	Percentage (%)
0-30	181-210	3	15
31-60	211-240	6	30
61-90	241-270	9	45
91-120	271-300	2	10
121-150	301-330	0	0
151-180	331-360	0	0
Total		20

Table 8: Frequency table for joints observed at Ndi-ogbu stream,Igbeagu

Class interval(⁰)	Correspondence interval(⁰)	Frequency	Percentage (%)
0-30	181-210	0	0
31-60	211-240	2	13.3
61-90	241-270	9	60
91-120	271-300	1	6.7
121-150	301-330	3	20
151-180	331-360	0	0
Total		15

3.5.2: FAULTS

Faults in the mapped area were observed at Ebonyi River and Ogbuenyanwu (Ebonyi River).The horizontal displacement between the shales-silt contacts on opposite walls show evidence of fault movement. There are presences of the hanging walls and foot walls and between them is the foot plane. The fault zone generally trend NE-SW directions. The fault zone is characterised by wedge shaped slabs of crushed and brecciated country rocks and in the fault planes are fractures filled with quartz minerals.

McConnell (1949) stated that during the folding, thrust faults and shear faults were developed and are often near the of the Abakaliki anticlines. This type of faulting would normally be expected in an intensely disturbed belt and this was observed at Ebonyi River.

Foot Wall Fault Plane

Normal Fault Hanging Wall

Figure2: Fault seen at Ebonyi River, Ndiechi-Onuebonyi

3.5.3: FRACTURES:

Series of fractures exist with approximately one-directional trend running across the mapped area. The fractures of the mapped area are located at the weathered zone of the host rocks. The fractured joints are filled with quartz minerals. The fractures are located at EbonyiRiver and the trends are running NE-SW directions.

CHAPTER FOUR

GEOCHEMISTRY

4.1 MATERIALS

In the course of this reseach work,many materials were used to ensure the success of the work.The materials are divided based on the places they are used.The materials are divided into field and laboratory materials.

4.1.1 FIELD MATERIALS

These are the materials used in thecourse of this reseach work in the field.The field materials are enumerated and discussed below:

· Based Map:This is the geologic map used for the location 0f the contour where the outcrops are found,accessibility and recording features taken from the field.

· Brunton Compass: This is used to know the direction and measurement of the altitudeof the bedding planes,and the strike directions of tectonic structures like joints,faults and veins of the beds.

· Geologic Hammer:This is used for the loggingof the sedimentary rocks,collection of fresh samples for analysis and scaling whentaking pictures.

· Field Notebook:This is used for keeping the accurate records of observation and measurement made in the field.

· Pen and Pencil:this is used for writing and drawing respectively.

· Measuring Tape and Rulers:This is used for measuring the thickness of the beds.

· Sample bag:This is used for the carriage of fresh samples taken from the field and collection of soil sample for analysis.

· Water Cans: These are used for collecting water samples for analysis.

· Masking Tape:for labelling of samples.

· Camera:Used for btaking pictures of structures of interest in the field.

· Global Positioning System (GPS): Used for noting position the position of interest in the field.

4.1.2 LABORATARY EQUIPMENTS

These are the materials used in the L aboratory for analysis.The equipments are divided into materials and the chemicals used in the laboratory to carryout geochemical analysis.

(1) Material: The materials used for the geochemical analysis are enumerated below;

· Sample bottles of water:It contain water for geochemical analysis.

· Masking Tape:for labelling of the water samples another equipment used for analysis.

· Paper:It is used for recording the results of the analysis done.

· Pen:It is used for writing done the results determined.

· Pipette:It is used for collection samples for titration.

· Conical flask:To pour the water samples collected with pipette.

· Atomic Absorption Spectrophotometry (AAS): Used in the analytic determination of the chemical elements.

· PH Meter:Determining the PH of the water samples.

· Conductivity meter:determination of conductivity of water.

(2) Chemicals

· Concentrated Nitric acid(HNO₃)

· Distilled deionized water

4.2 PARAMETERS ANALYSED

The parameters to be analysed in the course of this study are divided into levels.Level one are the physical parameters of the water samples which are made up of colour,hardness,PH,Total solid and dissolved solid while the second level are made up of the anions and cations of elements found in the water samples analysed.The anions are chloride(Cl^-),sulphate(SO₄^2-),and Nitrate(NO₃^-) while the cations are Magnese (Mn),Lead(Pb),Nickel(Ni),Zinc(Zn),Sodium(Na) and potassium(K).These parameters were all determined in the laboratory to find their avalaibility in all the water samples.

4.2.1 Colour:Water colour comes as a result of mixture of organic matters andsuspended particles.Noticeable water problems tend to involve unusual colours, smells and tastes.It is one of the physical parameter of water that determine the taste and odour of water and also the type of treatment to be given to it.

4.2.2 PH of WATER ANALYSED

This is defined as the negative Logarithm of hydrogen ion concentration. The concentration range suitable for the existence of most biological life is quite narrow and critical.

PH=-Log₁₀(H⁺)=Log₁₀(1/_aH⁺)

Its definition was adopted because ion selective electrodes, which are used to measure PH respond to activity.PH value is used to determine the alkalinity and the basic of a solution. A solution with a PH less than seven (7) are said to be acidic while any one greater than seven (7) are basic. Pure water has a PH value of seven (7).

4.2.3 TOTAL HARDNESS OF WATER

Hardness is defined as a characteristic of water which represents the total concentration of calcium carbonate (CaCO₃) equivalent.Hardness of water was originally defined in terms of its ability to precipitate soap.Calcium and Magnesium ions are the principle causes although iron,aluminium,manganese,Strontum,Zinc and Hydrogen ions are capable of producing the same effect.High concentrations of the later ions are not commonly found in natural waters.Large amount of hardness are undesirable for aesthetic and economic reasons in many industries and must be removed before the water is suitable for use.Taking the beverage food,laundary,metal finishing,dyeing and textiles,pulp and paper industries.Level above 500mg/l hardness are undesirable for domestic uses and most drinking water supplies average of 250mg/l.

4.2.4 TOTAL SUSPENDED SOLID

This is due to the presence of insoluble particles. The suspended solids mean particles over 1 x 10^-4nm in size which are retained on a filter paper. These may be particles of day, sand, various silicate and so on large amount of suspended solids get into water withy thawing snow and rainfalls. It can be measure by filtering the sample through a filter paperidry in an oven weigh.

4.2.5 TOTAL DISSOLVED SOLIDS

This is due to soluble substance in the water. The total dissolved solids is the weight of the dry residue remaining after a sample of water has evaporated. The level of total dissolved solids increases the hardness of water.

4.2.6 CHLORIDE

Its ion occurs naturally in water and it increases as the mineral content increases: sources of chloride in natural waters include chloride dissolved from top soil, oceans and sea water enchroachment. Human urine is highly saline and its percolation increase the salt content. Chloride in low or normal concentration that is, chloride amount acceptable by the World Health Organisation Standard is 250mg/L butaboree this limit is harmful. It gives the water taste. High chloride concentration in water should be avoided.

4.2.7 SULPHATE

The sulphate ion (SO₄^2-) occurs in natural water along with the chloride ion it enters the water through the dissolution of sedimentary (stratified) rock containing gypsim. The sulphate (SO₄^2-) ion is formed by the oxidation of hydrogen sulphide or native sulphur. Important source of sulphate in water is industrial sewage. The sulphate ion content of water in rivers and fresh water lakes does not exeed 100mg/L. the presence of large amoun of sulphates in water is undesirable since Na₂SO₄ interfers with the normal function of the body. Water containing large quantity of sulphate is corrosive.

4.2.8 MANGANESE

It is a chemical element with symbol Mn and atomic number 25. It is not found as a free element in nature. Manganese is often found in combination with iron and minerals. The occurrence of manganese and iron in public water supply present more of economic problem to health hazards. The presence of excessive iron and manganese in water creates serious problems. Iron and manganese affect laundary operations, causes dark stains on plumbing fixtures and porecelain. Support bacterial growth in distribution system and impact objectionable taste to water and beverages such as coffee and tea.

4.2.9 LEAD

Lead is a toxic substance with no know physiological function. There are various industrial activities which increases lead to the environment. Most of them are

a. TEL (Tetraethyl Lead (PbC₂H₅)₄ used as antiknock in engine.

b. Home made gin and whisky distilled using autoradiation and condensers. Consumption of fishes from river is also one of the sources where lead contaminated or agricultural product grown, and the contaminated water were used for irrigation (Lead Contaminated Soil). It is an accutrulative poison whose effects are documented. The World Health Organization (WHO) recommended maximum in take as 3.Mg/Wk in 1992, 0.1mg/L in drinking water in 1971 lead has no beneficial effects, therefore should be avoided.

4.2.10 NICKEL

Nickel, seldom found in natural water, is often present in industrial waste waters as acorrosion production of stainless steel and nickel allow and from metal nplating baths.

4.2.11 ZINC

Zinc ion is one of the most abundant of the trace elements of the human body and also an essential co-factor for manyimportance enzymes systems. Moderately increased concentration of zinc in the drinking water supply, derieved from zinc piping in domestic and other buildings are drequently found. Zinc ion is toxic to plant at higher concentration. Its permissible limit for drinking water by W.H.O is 0.1mg/L.

4.2.12 SODIUM

Sodium ion (Na⁺) is one of the cation found in water u in oceans, rivers and streams. Drinking water usually contains about 50mg/L sodium. This value is clearly higher for mineral water. In soluble form sodium always occurs as Na⁺ ions. Sodium compounds may occur as sodium chloride and sodium carbonate in water (Na₂ CO₃). Sodium compounmnds are used for industrial purposes such as its application in metallurgy, colling agent in nuclear reactors and as synthetic fertilizer. It can also be userd as chloride gas, preservative or a flavouring agent.

4.2.13 POTASSIUM (K)

Potassium ion (K⁺) are contained in sea water, rivers, lakes and streams. They are also seen calcium rich granite which contains up to 2.5% potassium. It react with water to form a coloutless basic potassium hydroxide solution and hydrogen gas. Potassium are moved into water through fertilizer and clay soil during weathering processes where it settles in sediments.

4.2.14 NITRATE

Methods of analysis

There are different methods that were employed in the fulfilment of the aims and objectives of this research work. The methods of analysis were carried out in two stages, the field stages and laboratory stages. The field stages involves the field work stage and sample collections stages while the laboratory stages involves the sample preparation, laboratory work and sample analysis.

4.3.1 FIELD WORK/SAMPLE COLLECTION STAGES

He field work stages where outlined below:

v Desk studies: This stages involves all the preliminary work done before the main field work. Desk studies involves the consultations of different literatures and consultation of different books based on the study area.

v Reconnaissance Survey: This stage involves the preliminary survey to get acquitted with the study area. It also includes all the accessibility of the different location where the outcrops are seen.

v Detailed Mapping: In this stage, all the outcrops were taken considerations. The places where they are seen such as the road cuts, erosional surfaces and stream channels were studied. The structural features such as joints, faults, veins, and the bedding planes were observed. Altitude of and joints were measured along with other parameters found in a particular location. Important geological features were snapped with the aid of a camera. Fresh samples were collected from the insilu of the outcrops visited.

v Water Sampling: A total of sixteen water samples were collected, seven (7) from boreholes, four (4) from well, one (1) river, one (1) pond and three (3) streams. Global position system (Gps) was used to located the co-ordinates of the sampling points. The sample were designated (GuC 01-GuC 16 for Gloria Ukwa Chiom a sample one to sample sixteen (16) respectively.

4.3.2 LABORATORY METHODS OF ANALYSIS

(1) Determination of pH

Apparatus/Reagent: PH meter (Electrometric) and its model is medular tolledo pH/ion 230, beaker, glass electrodes, buffer solution with pH value of 4.0

Procedure:The pH 4.0 buffer was prepared by dissolving pH buffer powder in 100ml of distilled water. The pH meter was pligged to a 2200 main supply and switch on to warm up. The pH buffer was used to standarlize the pH meter. This was done by connecting glass electrode to the pH meter and inserling electrodes into the buffer solution. This was allowed to stabilize and pH meter reading indicates 4.0 as this is the known pH value. The beaker containing the buffer solution was replaced with the one that is containing the samples. Each samples was tested and their different respective readings were taken record off.

(2) Determination of electrical conductivity

Apparatus: Conductivity meter (medular tolledo conductivity S220), electrode and beakers.

Procedures:The electrodes were wetted with distilled water and were plugged into the conductivity meter, then, the electrode was inserted into a 250ml beaker containing distilled water. The distilled water was replaced with the raw water samples electrodes were inserted in each cases, and the meter was allowed to stabilize and the reading was taken from the digital read out system. The instrument measures conductivity in microsiemen percetimeter and is written as µs/cm.

(3) determination of total solid (Ts)

Apparatus: Measuring cylinder, evaporating dishisilica crucible desicator, weighing balance.

Procedure: A silica crucible was heated, coolod in a desicator and then weighed. This process of heating, cooling and weighing was repeated until a constant weight was obtained. The 200ml of the raw water sample was taken on a water bath. The solid residue was heated and cooled 10(g) = W₂-w₁

W(g) = Weight of solid in gram

V = volume of water samples used

W₁ = Weight of crucible only

W₂ = Weight of crucible and solid residue

(4) DETERMINATION OF TOTAL DISSOLVED SOLID

Apparatus: Weighing balance, desicator, measuring cylinder, silica crucible, evaporating dish, water bath, muffle furnance.

Procedure: The evaporating dish was weighed in a weighing balance and the weight noted as Wi 100ml of the water sample was then put in the dish and dried in a water bath. The evaporating dish and its content was transferred to a muffle furnance operated at 103⁰C for proper drying for one hour. The dish was finally weighed with its content and the weight is known as W₂. The difference in weight gives the weight of the total dissolved solids of water sample.

TDS

W₁ = Weight of evaporating dish

W₂ = Weight of evaporating dish + solid residue

W₂ – W₁ = Weight of solid residue

Ml = 100ml of water used.

(5) DETERMINATION OF TOTAL HARDNESS

Apparatus/Reagent:Conical flask, measuring cylinder pipette, burette, report stand, stirrer, indicator, EDTA.

Procedure: 100ml of water samples was measured with a measuring cylinder into a conical flask, and 1ml of ammonia buffer solution was addedand stirred properly. Three drops of Erichrome black T indicator was added and the solution was titrated with 0.02m EDTA solution until the colour changes from wine red to pure blue without any reddish remaining.

Calculation

Total hardness (Mg/l CaCO₃)

Where T = millilitre of titration for sample (EDTA standard solution).

B = millilitre of CaCO₃ equivalent to 1.00ml of EDTA titrant.

(6) DETERMINATION OF CHLORIDE

Apparatus/Reagent: Potassium chromate indicator (K₂CrO₇) solution 0.01m silver nitrate.

Procedure: 10ml of the raw water sample was added into conical flask fewdrops (3 drops/2drops) of indicator was added into the water sample. Titrate with 0.01m silver nitrate (AgNO₃). Observations of colour which changes from yellow colour to light orange. The reddish-brown/light orange showed the end point. The volume of silver Nitrate used was recorded.

Calculation

Mg/lC^-1

T = Titre value

N = Normality of AgNO₃

(7) NITRATE DETERMINATION

Apparatus/instrument-Nill

Procedure: 50ml of water samples was measured and pour into a conical flask or test tube. Add 1ml of sodium accenite and shake thoroughly remove from the mixture above 5ml of solution into a separate test tube. Add one millilitre (1ml) of brucine sulphate (0.1m), add also 10ml of concentrated sulphuric acid (H₂SO₄). Mix the remaining 45ml solution with the above mentioned reagents. Allow the solution of develop for about 30 minutes to 1 hour for them to absorb. Then, read the absorbance with the acid of a spectronic 20 machine.

Calculation

To calculate for Nitrate

(8) sulphate Determination

Instrument – Nill

A water sample of 10ml was pipetteinto a conical flask. Then, 5ml of 2m hydrochloric acid (HCl) was added, also 5ml of 0.05m Bacl₂was added into the solution. It was boiled for 5 minutes and allow to cool. Added to the solution are 2ml of ammonia (NH₃), 0.01m of EDTA and boil for 5 minutes.. the sample was added also 5ml of buffer one or three (1 or 3) drops of Eviot (solochromo black) indicator and the solution was titrated with 0.01m of magnesium chloride (MgCl₂). The solution was observed to have some colour changes from blue to light purple which marked the end point.

Calculation

Sulphate

Where

TV = Titrete value of the sample

96.01464 = molecular weight of sulphate

Ml = 10ml of water used.

(9) Determinationof concentration oflevel of metals (Pb, Zn, Mn, Ni, Na, K, Cu, Cd and Cr)

Instrument: Atomic Absorption spectrometry (A.A.S), Model Bulk Scientific V.G.P 210

Uses of atomic absorption spectrometry (A.A.S)

Mg/l: Atomic Absorption spectrometry (A.A.S) is an instrument used in analytical determination of elements and their concentration in water samples, food and beverages. AAS can also be used in the analysis of clinical and biological samples, effluents, soil, plants, fertilizer, mineral, cosmetics, petroleum products and pharmaceuticals.