First detailed stable carbon and oxygen isotopic of Miocene sediments in the Northeast Indian Ocean. Important successions of global and regional paleoceanographic and paleoclimatic changes were observed. A strong westerly Indian Ocean current linked South Pacific, Indo Pacific and Northeast Indian Oceans between 14 and 9 Ma. Initiation of Indian Summer Monsoon (ISM) at 12 Ma probably caused high productivity event in the Northeast Indian Ocean. Evidence of increased input from the North Atlantic Deep water (NADW) at ~ 10 Ma.