SEDIMENTS AND MARINE MINERAL-RESOURCES IN THE EASTERN INDIAN-OCEAN

Sedimentation regimes are an important control on the distribution of marine mineral resources worldwide. In the eastern Indian Ocean, phosphorites are associated with organic-rich sediments including coral reefs on continental margin areas, principally off western India, and possibly occur on seamounts throughout the equatorial and subequatorial parts of the region. Metalliferous sediments and polymetallic sulfides can be expected to be located in areas of volcaniclastic and hydrothermal sedimentation in and near the Indonesian Island arcs and on the mid-ocean ridge system, the Southeast Indian Ridge. Manganese nodules are both abundant and high grade in the central Indian Basin in association with slowly accumulating manganese-rich pelagic clays, and sediment data suggest that a similar situation may prevail in the Wharton Basin.