Diversity, evolution and palaeoecology of the Tertiary bryozoan assemblages of western Kachchh, Gujarat, India

The Kachchh Basin, a pericratonic rift basin in the western margin of India, represents one of the classical areas of Indian geology, which has preserved a condensed section (about 900 metres thick) of the Tertiary rock sequences (Figure 1) ranging from Paleocene to Pliocene. These sequences (Table 1) have been classified on chrono-, litho-and biostratigraphic basis, the boundaries of which are somewhat parallel and seldom mutually transgressive (Biswas & Raju 1973, Biswas 1992, Raju 1993, 1997).