Neogene planktic foraminiferal biochronology of the central Indian ocean DSDP Sites 237 and 238

Abstract

Qualitative and quantitative planktic foraminiferal analyses of the Central Indian Ocean DSDP Sites 237 and 238 provided 34 important events during the Neogene. A comparison of the chronological succession of ihese planktic foraminiferal (.'vents.wiih the othertropical Indian Ocean and Southwest Pacific DSDP Sites reveals remarkable similarity. Therefore, these Neogene foraminiferal events [First Appearance (FA) and List Appearance (LA)} are considered as synchronous within the tropical Indo-Pacific except Gq. dehiscmiAd. Gr. mrganmt FAD. range of Gr. tUmidaflextiutQ, Gr. crassaformis FAD. Gr. truncatulimdes FAD. and Gs. tMtftm LAO. which arc diachrcnous reflecting their paleobicgeognphtc control, S[ratigraphic ranges of planktic forarmnifcra enabled recognition of 20 zones from the late Early Miocene to Pleistocene.