The tectono-stratigraphic evolution of the Arakan Yoma Orogen wi th the Naga and th e Chin Hill s, positi oned between th e Sunda arc and th e Himalayas, is vital in th e framework of convergence of the Indi an plate with Asia. The Orogen is flanked to th e west by the Assam-Burma Cretaceous-Tertiary turbidite-molas e basin and furth er west by the Meghalaya (S hillong) Plateau; to th e east by the Mesozoic-Cenozo ic Cenu·at Burman molasse basin and th e Shan-Tenasserim block east of th e Shan Boundary Fault. From the above tectono-stratigraphic sett in g it is surmised that the present ire of aga Hills - Ar­ akan Yoma- Chin Hills has been marked by a meridjonally trending spit of l