Cenozoic Marine Sediments of Long Island, Andaman Sea

The paper briefly describes the sequence of Cenozoic marine sediments that occur on Long Island, Middle Andaman, northeastern Indian Ocean. The stratigraphic sequence recognized is based mainly on the study of smaller foraminifera from measured sections in the western, and eastern parts of the island. The occurrence of Neogene strata on Long Island has been known for some time but until now Paleogene rocks have not been reported from Long Island or any of the other islands east of the main Andaman ridge. The Paleogene strata represented by the Conglomerate and Grit Formation (Port Blair Series) occur only in the northern part of the island, forming the basement upon which the Neogene sediments were deposited. The Neogene strata of Long Island are represented by Inglis Formation (Early Miocene), Long Formation (Late Miocene) and Guitar Formation (Pliocene). The Long Formation yielded rich foraminiferal assemblages, while the recovery from the other two formations was poor.