干旱区生态环境知识资源中心

A critical study of the literature on the Quaternary of Mauritania confirms the field evidence of a succession of arid and humid climatic phases, and emphasizes the lack of sufficient precise dating. Marine deposits show that transgressions begin during the end of dry phases and reach a maximum during and after the succeeding wet episodes.

Taking into account high sea level deposits that are correlated with the Shackleton-Emiliani curve (stages with odd numbers), it is possible to suggest different possibilities for the chronology of the local lithostratigraphic formations of Pleistocene age. (Figs 1 and 2). For the last 15 ka, the Servant curve (Fig. 3) gives the most accurate amplitude of possible environmental and rainfall changes, while its (uncalibrated) chronology can be improved by using statistical frequency of all lacustrine dates.

Because of lack of paleogeographical maps for the last arid maximum (or for the LGM.) and for the humid Holocene, it is difficult to quantify the effect of these changes on the total biomass and on the carbon cycle. For this reason the effect on the future Mauritanian environment of the increasing greenhouse gases in the atmosphere needs further investigations.