Fig. 4

Palaeogeographic map of early Eocene showing distribution of glauconite–phosphorite, glauconite–lignite and glauconite–oolitic ironstone associations (adapted from Boucot et al. 2013). Note that extensive lignite–glauconite association occurs at the eastern part of Tethys along the Indian subcontinent (numbers correspond to those provided in Table 1)