1 Institute of Earth Sciences, Faculty of Sciences and Techniques, Cheikh Anta Diop University of Dakar, Dakar, Senegal. 2 Department of Geology, Faculty of Sciences and Techniques, Cheikh Anta Diop University of Dakar, Dakar, Senegal.
The analytical results of water samples collected from the Dindefello
Plain area revealed the dominant major ions of bicarbonate, silica, calcium,
magnesium and sodium, in
order of decreasing relative abundance. Spring water
exhibited a very low, i.e. similar to
rainwater, mineralization status, unlike groundwater. To better understand the
origin of mineralization, the data were further analyzed for interrelationships
between parameters and for mineral-water relationships using speciation calculations. This provided various tenuous
lines of evidence for speculating various modes of groundwater mineralization.
Hydrochemical evaluation of major ions suggested an early stage of
mineralization which could be attributed to mineral breakdown driven by pH in
the vadose zone under the leaching action of H+. Conceivably the
soil in recharge areas supplies CO2 to infiltrating rainwater, thus
adding to the amount of aqueous CO2 (H2CO3) already
entrapped from the atmosphere. Then, H+ ions, produced from the
dissociation of aqueous CO2 (
), reacts along
groundwater flow paths with the carbonaceous-sulfated and silicated
minerals, resulting
in the observed major ion chemistry. The spatial variations in the groundwater
chemistry indicated that the type of bedrock aquifer has an effect on the water
chemistry.
Senegal, Dindefello, Groundwater Mineralization, Springwater, Hydrogeochemical Evolution, Chemical Weathering
Diop, S. , Diome, F. , Samb, M. and Sarr, R. (2014) Hydrogeochemical Relationships between Spring and Subsurface Waters in the Dindefello Area of South Eastern Senegal. Journal of Water Resource and Protection, 6, 1743-1754. doi: 10.4236/jwarp.2014.619156.
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