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Geological investigations in the Oujda region (eastern Morocco) of the period corresponding to the last hundred thousand years have made it possible to discover several geological and archaeological sites which are rich in charcoal. By including information from Prehistory, absolute chronology and palaeoenvironmental studies, the data from charcoals analyses can be placed in their context. This allows us to outline the bioclimatic evolution of a poorly known region.

From north to south there is a decrease in climatic fluctuations. As the Beni-Snassen Mountains evolved from an humid to semi-arid climate (supraoromediterranean to thermomediterranean), the Angads Plain and the Oujda Mountains remained under thermomediterranean conditions with slight fluctuations between sub-humid and semi-arid. Southwards, the Alfa and Artemisia steppe dominated the northern part of the Hauts-Plateaux, with some variations from an arid climate.

In the Oujda Mountains the data are abundant, and the climatic fluctuations which are indicated by the flora, sediments from rock shelter sites and fluvial terraces, indicate that the Soltanian (last glacial) is principally a dry period, within a semi-arid climate. This climate is temperate to cool and interrupted by three periods of warmer and more humid conditions. The Rharbian (= Holocene) begins ca 12,000 B.P., with a slightly more humid phase, which is followed first by a short arid period and later by the climatic optimum which is warm and humid (6000-4500 B.P.). The return of the arid climatic conditions occurs at ca 4000 B.P. but they are interrupted by a short more humid phase (3000 to 2000 B.P.).