HE-3 IN INDONESIAN SEAS - INFERENCES ON DEEP PATHWAYS

Helium isotope measurements from the Indonesian Seas, and from the Jav a-Australia Dynamic Experiment cruises define mantle He-3 sources and deep water spreading patterns. He-3 sources in the Sulawesi Sea and in the Makassar Strait are found, but these are prevented from spreading into the Banda Sea and the Indian Ocean by blocking sills. A major ma ntle source is identified below 2000m in the Flores Sea. The He-3 dist ribution suggests that the Banda Sea water migrates westward along the floor of the Flores Sea, upwells and then advects the high He-3 Flore s signal. A tongue of higher-than-ambient He-3 on the Indian Ocean sid e of the Flores chain indicates a deep outflow of the Flores and the B anda Sea water into the Indian Ocean near 1300m.