ABSTRACT Stable isotopes of oxygen-18 and deuterium content in groundwater, surface water and rainfall in the northern part of the Densu river basin were studied with the main aim of identifying the origin and sources of ions in the groundwater in the area. The conversion of stable isotopes to d-excess was also exploited as a complementary tool to understand the processes of recharge. A comparison of the isotopic data with the rainfall, Local Meteoric Water Line (LMWL) and Global Meteoric Water Line (GMWL) indicates that the groundwater in the study area is mainly meteoric with few groundwater and all the surface water showing an evidence of evaporation. The study has also shown that, mineral dissolution from the geology is the main factor controlling the chemistry of the groundwater with evaporation having a minimal effect. The d-excess values show that the groundwater has undergone dilution with the rainfall and this is observed from the decrease of the d-excess of the groundwater with increase in Oxygen-18. This observation also suggests a modern day recharge to the groundwater.
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nullA. Gibrilla, S. Osae, T. Akiti, D. Adomako, S. Ganyaglo, E. Bam and A. Hadisu, "Origin of Dissolve Ions in Groundwaters in the Northern Densu River Basin of Ghana Using Stable Isotopes of 18O and 2H," Journal of Water Resource and Protection, Vol. 2 No. 12, 2010, pp. 1010-1019. doi: 10.4236/jwarp.2010.212121.
 T. T. Akiti, “Environmental Isotope Study of Groundwater in Crystalline Rocks of the Accra Plains,” 4th Working Meeting Isotopes in Nature, Proceedings of an advisory group meeting, IAEA, Vienna, 1986.
 B. K. Das, Y. P. Kakar, H. Moser and W. Stichler, “Deuterium and Oxygen-18 Studies in Groundwater of the Delhi Area, India,” Journal of Hydrology, 1998, pp 133- 146.
 G. Faure, “Principles of Isotope Ge-ology,” John Wiley & Sons, New York, 1986.
 H. Craig, “Isotopic Variation in Meteoric Water,” Science, Vol. 133, No. 3465, 1961, pp. 1702-1703.
 W. Dansgaard, “Stable Isotopes in Precipitation,” Tellus, Vol. 16, No. 4, 1964, pp. 436-468.
 J. Jouzel and L. Merlivat, “Deuterium and Oxygen-18 in Precipitation: Modeling of the Isotope Effects during Snow Formation,” Journal of Geophysics Research, Vol. 89, No. D7, 1984, pp. 11749-11757.
 J. R. Gat, C. Bowser and Kendall, “The Contribution of Evaporation from the Great Lakes to the Continental Atmosphere: Estimate Based on Stable Isotope Data,” Geophysics Research and Letters, Vol. 21, No. 7, 1994, pp. 557-560.
 A. Kondo and J. Shimata, “The Origin of Precipitation in Eastern Asia by Deuterium Excess,” Journal of Society of Hydrology and Water Resources, Vol. 10, No. 6, 1997, pp. 627-629.
 J. C. Fontes, “Environmental Isotopes in Groundwater Hydrology in Handbook of Environmental Iso-topes Geochemistry,” Fritz and Fontes, Vol. 1. Elsevier, 1980, pp. 75-140.
 IAEA, “Guidebook on Nuclear Techniques in Hydrology,” Edition Technical Report Series No. 91, Vienna, 1983.
 K. B. Peligba-Ba, “Analysis of Stable Isotope Con-tent of Surace and Underground Water in Two Main Geological Formation in the Northern Region of Ghana,” West Journal of Applied Ecology, Vol. 15, No. 1, 2009.
 B. K. Kortatsi and N. K. Sekpey, “Chemical and Isotopic Techniques for the Origin of Groundwater in the Crystalline Basement Complex of the Upper Region of Ghana,” Regional Trend in Geology in African Geology, Proceedings of the 9th international Geological Conference, Accra, November 1992.
 K. B. Ba-noeng-Yakubu, “Application of Remote Sensing and Geo-graphical Information System to Hydrological Studies in the Upper West Region of Ghana,” 2000.
 S. Y. Acheampong and J. W. Hess, “Origin of the Shallow Groundwater System in the Southern Voltaian Sedimentary Basin, Ghana,” Hydroge-ology Journal, Vol. 6, 2000, pp. 527-537.
 J. R. Fianko, O. Osae, D. Adomako and D. G. Achel, “Relationship between Land Use and Groundwater Quality in Six Districts in the Eastern Region of Ghana,” 2008.
 K. B. Banoeng-Yakubu, “Occurrence of Groundwater in Basement Complex Rocks of the Upper Region of Ghana,” M.Sc. Thesis, Obefemi-Awolowol University, 1989.
 S. Y. Ganyaglo, “Hydrochemical and Isotopic Characterization of Groundwater in Some Rock Types in the Eastern Region of Ghana,” Unpublish Mphil Thesis, 2009.
 S. N. Davis and L. J. Turk, “Optimum Depth of Wells in Crystalline Rocks,” Groundwater, Vol. 2, No. 2, 1964, pp. 6-11.
 D. K. Buckley, “Report on Advisory to Wateraid Projects in Ghana,” Unpublished Report, British Geological Survey, Hydrogeology Research Group, Willingford, 1986.
 P. Seismos, “The 30 Well Project,” Internal Report, Cath- olic Diocese of Accra, 1984.
 Water Research Institute (WRI), “Borehole Yield Map of Ghana,” Unpublished Technical Report, Accra, 1994.
 Goucey, et al., “Application of Isotope Techniques for the Assessment of Groundwater Resources: Densu River Basin Report,” 2008.
 P. S. Datta, D. L. Deb and S. K. Tyagi, “Assess-ment of Groundwater Contamination from Fertilizers in the Delhi Area Based on δ18O, NO3- and KC Composition,” Jour-nal of Contaminant Hydrology, Vol. 27, No. 3-4, 1997, pp. 249-262.
 K. P. Bam, “Major and Trace Elements in Soil Profile of the Unsaturated Zone of the Densu River Basin, Ghana,” Unpublish Mphil Thesis, 2009.
 P. S. Datta, D. L. Deb and S. K. Tyagi, “Stable Isotope (δ18O) Investigations on the Processes Controlling Fluoride Contamination of Ground-water,” Journal of Contaminant Hydrology, Vol. 24, No. 1, 1996. pp. 85-96.
 F. Yuan and S. Miyamoto, “Characteris-tics of Oxygen-18 and Deuterium Composition in Waters from Pecos River in American Southwest,” Chemical Geology, Vol. 255, No. 3-4, 2008, pp. 220-230.