The study area is Abakaliki and its Environs which include villages in Ebonyi and Abakaliki Local Government Area of Ebonyi State. (Fig 1). Villages within the study area include Ugboloke, Agbaja, Ogbuchi Amechi, Ndiechi Igbaegu Onuebonyi, Ekaeru-Inyimagu and Abakaliki urban. However, only sedimentary rocks of lower cretaceous age (Albian) are exposed in the area mapped. The sedimentary rocks are predominantly black carbonaceous shale with intercalation of thin calcareous matter.
The base line data for the occurrence of assessment of heavy elements were needed as one of the criteria for its distribution and level of concentration in stream sediment around Abakaliki and its environs. The composition and concentration in streams sediments vary from one place to another depending on its origin,
In the study area, twenty samples from stream sediments were collected and analysed for copper (Cu), lead (Pb), zinc (Zn), cadmium (Cd), arsenic (As) and nickel (Ni). The result proves the existence of these elements or its absence and also the level of their concentration and distribution in the stream sediments.
Fig 1: Map of Nigeria and Ebonyi State with the Study Area
LOCATION, EXTENT AND ACCESSIBILITY
LOCATION, EXTENT AND ACCESSIBILITY
The study area falls within Ebonyi State (Fig1) particularly Abakaliki and its environs which includes villages like Ekaenu Inyimagu, Onuebonyi, Ogbuchii Amaechi, Agbaja, Ugboloke, Ndiedi Igbeagu (see fig 2) The area is geographical located between latitude 6015'N and 6020'N and longitude 8005'E and 8010'E covering a total area of about 81km2.
The areas were accessed through Enugu, Ogoja, and Afikpo through a network of tarred roads which include the Abakaliki Enugu Express road, Abakaliki Ogoja Express road and Abakaliki-Afikpo Express road. During the fieldwork, vehicles, motorcycles and footpaths were employed to aid accessibility and movement through the outcrop locations and sample collections.
AIMS AND OBJECTIVES OF STUDY
This work is primarily aimed at presenting geologic studies and geochemical analysis of heavy elements in stream sediments within Abakaliki and its environs particularly on Iyiokwu river. This is to study the geology of the area and also understand the dispersion mobility and total concentrations of the heavy elements in the area. The aims and objectives of this research work can be outlined as follows:
• To delineate the areas of excessive or deficient levels of these trace elements (Pb, Zn, Cu, As, Ni) in the study area.
• To determine the pattern of heavy elements concentration and distribution in the sediment.
• To determine the various geological factors that affect or control the distribution of these heavy elements
• To determine the mineralogical and human factors that controls or affects the distribution pattern of these elements.
• To access the pollution status of the area by comparing their metal concentration with established standards.
SCOPE OF STUDY
The study area, Abakaliki and its environs are limited in scope because not all the analyzable trace and heavy elements and other parameter in the sediment were determined. The elements determined include heavy elements such as lead, copper, zinc, cadmium, arsenic and manganese. And these elements are the most important because of its occurrence in the study area.
The determination of the total concentration of heavy elements in the stream sediments of the study area was done by the use of Buck scientific atomic absorptions spectrophotometer. The samples were collected from the stream sediments along the river channel.
The areas were accessed through Enugu, Ogoja, and Afikpo through a network of tarred roads which include the Abakaliki Enugu Express road, Abakaliki Ogoja Express road and Abakaliki-Afikpo Express road. During the fieldwork, vehicles, motorcycles and footpaths were employed to aid accessibility and movement through the outcrop locations and sample collections.
AIMS AND OBJECTIVES OF STUDY
This work is primarily aimed at presenting geologic studies and geochemical analysis of heavy elements in stream sediments within Abakaliki and its environs particularly on Iyiokwu river. This is to study the geology of the area and also understand the dispersion mobility and total concentrations of the heavy elements in the area. The aims and objectives of this research work can be outlined as follows:
• To delineate the areas of excessive or deficient levels of these trace elements (Pb, Zn, Cu, As, Ni) in the study area.
• To determine the pattern of heavy elements concentration and distribution in the sediment.
• To determine the various geological factors that affect or control the distribution of these heavy elements
• To determine the mineralogical and human factors that controls or affects the distribution pattern of these elements.
• To access the pollution status of the area by comparing their metal concentration with established standards.
SCOPE OF STUDY
The study area, Abakaliki and its environs are limited in scope because not all the analyzable trace and heavy elements and other parameter in the sediment were determined. The elements determined include heavy elements such as lead, copper, zinc, cadmium, arsenic and manganese. And these elements are the most important because of its occurrence in the study area.
The determination of the total concentration of heavy elements in the stream sediments of the study area was done by the use of Buck scientific atomic absorptions spectrophotometer. The samples were collected from the stream sediments along the river channel.
SETTLEMENT PATTERN AND CULTURE There are two types of settlements observed in the study area. They are dispersed and nucleated settlement. The dispersed settlement is found in Ekaenu Inyimagu, Obugha Amachi, Ndiedi Igbeagu. In these areas, dwelling places are scattered and isolated from each other while the nucleated settlements are observed in Abakaliki urban, Agbaja, and Azuiyiokwu.
The people of Abakaliki and its environs are of Igbo speaking Ethnic group, with different dialects. There major occupation is farming and mining activities. They practice both African traditional religion and Christianity.
The people of Abakaliki and its environs are of Igbo speaking Ethnic group, with different dialects. There major occupation is farming and mining activities. They practice both African traditional religion and Christianity.
GEOMORPHOLOGY Geomorphology has to do with the overall nature of the landform of an area.
Vegetation And Climatic Condition The vegetation of Abakaliki and its environs is Luxuriant vegetation of tropical rainforest. Its vegetation is densely populated with grasses and trees of different sizes in the area. The area is marked by undulated range of shale outcrops and the shales are either greyish or reddish brown in colour depending on its content and degree of weathering. The area had 400ft as its highest contour and 100ft as its lowest contour above sea level.
The climate of the study area is of Humid tropical climatic region. It experiences one rainy season and one dry season (eight months of rainfall and four months of dryness). Harmattan is felt between December & January. The mean annual temperature stands at 280C. Humility in this area is about 50-60% P.a. The mapped area has a mean annual rainfall of 2500mm. Rainfall is highest in September and lowest in January.
Drainage The drainage system of the study area is dendritic in pattern, as a function of lithologic control. The study area is mainly drained by Iyiokwu River, Iyiudene River and Ebonyi River with few minor drainage flows. All these, both the major and minor drainage system flow eastward to join the Cross River Somewhere outside the study area (see fig 3).
Fig 3: Map showing the drainage pattern of the study area
Soil Type The soil of Abakaliki and its environs is basically clayey, loamy clay and clayey loam soil. The clayey swampy soil is suitable for rice farming while the other types of soil can be used for yam and cassava cultivation.
Methodology Simple compass and traverse was employed in mapping the study area. The Brunton compass, Geologic hammer, sample bag, tapes, field note book, camera, pen, pencil, ruler, masking tape were used in data collection. A desk study and a review of past work on the study area and a reconnaissance study of the area were carried out before the actual mapping. The mapping involved the identification of description of the rock types and delineation and demarcation of their lithostratigraphic contacts using features like topography, vegetation and soil type.
Vegetation And Climatic Condition The vegetation of Abakaliki and its environs is Luxuriant vegetation of tropical rainforest. Its vegetation is densely populated with grasses and trees of different sizes in the area. The area is marked by undulated range of shale outcrops and the shales are either greyish or reddish brown in colour depending on its content and degree of weathering. The area had 400ft as its highest contour and 100ft as its lowest contour above sea level.
The climate of the study area is of Humid tropical climatic region. It experiences one rainy season and one dry season (eight months of rainfall and four months of dryness). Harmattan is felt between December & January. The mean annual temperature stands at 280C. Humility in this area is about 50-60% P.a. The mapped area has a mean annual rainfall of 2500mm. Rainfall is highest in September and lowest in January.
Drainage The drainage system of the study area is dendritic in pattern, as a function of lithologic control. The study area is mainly drained by Iyiokwu River, Iyiudene River and Ebonyi River with few minor drainage flows. All these, both the major and minor drainage system flow eastward to join the Cross River Somewhere outside the study area (see fig 3).
Fig 3: Map showing the drainage pattern of the study area
Soil Type The soil of Abakaliki and its environs is basically clayey, loamy clay and clayey loam soil. The clayey swampy soil is suitable for rice farming while the other types of soil can be used for yam and cassava cultivation.
Methodology Simple compass and traverse was employed in mapping the study area. The Brunton compass, Geologic hammer, sample bag, tapes, field note book, camera, pen, pencil, ruler, masking tape were used in data collection. A desk study and a review of past work on the study area and a reconnaissance study of the area were carried out before the actual mapping. The mapping involved the identification of description of the rock types and delineation and demarcation of their lithostratigraphic contacts using features like topography, vegetation and soil type.
Also lithofacies contact, dip and strike data and lithologic symbols were plotted on the map. Sampling was done on a grid of approx. 500m. They were picked from the bottom of river channels about 15cm deep made by use of picks and shovels. About 100g of fine fractions was put in a polyethylene bags and labeled. Gain eTrex GPs was used to locate each sample point by recording the Eastings and Northings of that point.
A total of 20 samples were collected, they were dried, homogenized and passed through 100mesh nylon screen. The samples were digested by use of aqua regia. The aliquot was analysed by use of Buck Scientific Atomic Absorption Spectrophotometer. (AAS)