(Table 1) Diatom species composition and distribution at ODP Site 116-717C

Allochthonous diatoms were transported to the equatorial Indian Ocean from inland locations and coastal waters, respectively. The pelagic diatom assemblage consists mainly of warm and/or tropical diatoms known from the Neogene to Holocene.

A stratigraphic marker, Rhizosolenia praebergonii var. robusta, which indicates Pliocene-Pleistocene (2.4-1.55 Ma) age of the sediments, was present in the samples from Core 116-717C-27X. Species composition of the whole assemblage is most similar to the tropical Indian Ocean Diatom Zone 6 of Schrader and supports an estimated age of 1.8-2.1 Ma for the sediments.