ABSTRACT
One of the major perils of archeology, of paleoclimatology, and of Saharan Pleistocene geology, has been the imprudent use of generalizations and the failure to recognize the necessity of detailed studies on a modest and efficiently regional scale. The Nile Valley, although crossing a considerable stretch of the Sahara, belongs partially to it, and represents a foreign element. This chapter is devoted to the examination of known facts, or of proposed hypotheses, for certain distinct geographical regions. It should not be forgotten that the outlined program implies the consideration, in space, of the border regions of the southern Sahara, and, in time, of the recent Tertiary. There are few things to be said about the late Tertiary: "no fossils, neither microfauna or macrofauna, have been found in the Terminal Continental." The chapter draws attention to three subjects: two sites, Tihodaine and Tejerhi, which have been the object of serious study, and the progress of the paleo-palynology of the central Sahara.
