CONTENTS

Evidence for major vegetation and climatic changes during the Tertiary in the south-west-ern Cape has been obtained from a number of sites. The palynomorph assemblages indicate in general an alternation of relatively cool temperate forests with two periods of subtropical-tropical palm-dominated vegetation from the Late Oligocene / Early Miocene to the Pliocene when many of the taxa became extinct. Subsequently, strong development of macchia vegeta-tion took place. These changes can be correlated with some palaeogeographic data and the major temperature changes of the Southern Ocean indicated in the palaeotemperature curve of Shackleton and Kennett ( 197 5) which reflects the longterm progressive cooling of the earth since the Eocene/Oligocene boundary. The two subtropical- tropical periods can probably be related to the respective Early and Middle Miocene pan-African faunas of Arrisdrift and Liideritz and could coincide with the two warmest periods of the Miocene at 19 My and 14 My ago. The end of the Miocene witnessed the maximum build-up of the Antarctic ice-sheet and the substantial increase of the upwelling in the Benguela Current. This resulted in the initiation of the aridification of the present Namib desert, the extermination of the pal