Fig. 5

Palaeogeographic map of middle and late Eocene showing the distribution of glauconite–phosphorite, glauconite–lignite and glauconite–oolitic ironstone associations (adapted from Boucot et al. 2013). Note that phosphorite–glauconite association is restricted to the eastern part of African continental shelf instead of the northern part. Scattered deposits with lignite–glauconite association occur within the tropical–boreotropical climatic belts (numbers correspond to those provided in Table 1)