First results of the isotopic study (18O, 2H, 3H) of the Douala Quaternary aquifer (Cameroon)

The quaternary sandy aquifer of the Douala sedimentary basin generally indicates homogeneity in isotopic abundance (18O, 2H, 3H) of water sampled at different depths. The large majority of these samples indicated a direct and fast infiltration of the precipitations, without significant evaporation. This homogeneity can moreover be accentuated under the pumping effects, putting in communication various levels of the multilayer aquifer. These results show that pollution from the surface can quickly reach the deeper layers, and seems to corroborate those obtained on the basis of field measurements and chemical analyses. (author)