Date of Award


Degree Type


Degree Name

Master of Science in Chemistry



First Advisor

Paul Abell


A stable oxygen isotopic study of modern African freshwater gastropod shells was carried out to ascertain the feasibility of the use of the stable oxygen isotope ratios of freshwater gastropods as paleoclimatic indicators.

In this study, the oxygen isotope ratios of the freshwater gastropod shell samples taken from the apertures of the individual shells collected at monthly intervals from one site were examined to ascertain their correlatability with weather, temperature, rainfall, water isotope ratios and other ambient conditions. The gastropod shell analysis was by the procedure of Abell (1985) and the water sample analysis by the method of Epstein and Mayeda (1953).

The monthly analyses of both water and gastropod shells from the tributary of the River Pra at Krobo, in the Western region of Ghana, approximately 700km from the Sahel, have shown amount effect, temperature effect temperature plots and evaporative effect·. Good parallelism between ' 18 and the S o plots of the shells and the water was observed. The s18o value~ were also in agreement with vegetative cover map of Ghana and Africa in addition to their correspondence with seasonality information.

Application of these results to fossil gastropod shells, however, requires additional geological and geographical data.