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Paleoclimatic implications derived from recent Quaternary diatoms of Diana Malari (Casamance, Senegal) Volume 16, issue 2, Juin 2005

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Département de géologie, Faculté des sciences et techniques, Université Cheikh Anta Diop (Ucad), Dakar, Sénégal

A core sample from Diana Malari on the Casamance estuary 228 km away from the sea provided 82 diatom species belonging to 27 genera. Thirty-five of these taxa are quoted for the first time in Casamance and 8 of them for the first time in Sene-Gambia. The following conclusions can be drawn from the qualitative and quantitative analysis of this microflora: during the whole of the deposit period, the estuary was very shallow, with probable emerging periods; the aridity of the environment, increasing from base to top along the sounding core, is interrupted by short rainy periods, two of which are prominent and have already been identified on Sedhiou’s core and dated back to 2500 and 140-120 BP; the climate was becoming warmer and warmer with maxima occurring during the rainy periods and the alkalinity of the environment was increasing.