ABSTRACT
Pollen/spore analysis and quantitative evaluation of clay mineral assemblages is used to interpret palaeoclimatic development in Oligo-Miocene to Quaternary in the Gezira area in central Sudan. The combined study shows a progressive development of climate from humid during Oligo-Miocene to dry conditions towards the Quaternary. The palynological assemblage is dominated by fern spores. The ferns include Cyatheaceae, Polypodiaceae, Adiantaceae, Lindsayaceae and Parkeriaceae. These fern families are associated with angiosperm families represented by Meliaceae, Bombacaceae and Guttiferae. These are chiefly tropical to subtropical families belonging to lowland rainforest communities. The dominant clay mineral in all studied sections is smectite. This mainly suggests volcanic character of the source rocks rather than reflecting climatic influence. However, the increasing quantity of smectite and kankar nodules in the post Miocene sediment suggests the development of arid conditions towards the Quaternary.
