The indian ocean-type isotopic signature in western pacific marginal basins: Origin and significance

Abstract

Basalts forming the floor of the western Pacific marginal basins sampled by DSDP and ODP legs and dredging cruises over the past 20 years have isotopic characteristics like those of basalts erupted at Indian Ocean spreading ridges, distinct from those of basalts from Pacific Ocean ridges. The basins, which include the Yamato and Japan Basins of the Sea of Japan, the West Philippine, Shikoku and Parece Vela Basins and Mariana Trough of the Philippine Sea Plate, the South China Basin, the Celebes Sea, the Sulu Sea and the Lau Basin, range in age from >60 to 0 Ma and have differing tectonic histories. The origin of the Indian Ocean-type isotopic signature in basalts from these basins has been i..