Deployment of Long-Term Seafloor Mineral Exposure Experiments to Measure Changes of Mineralogy and Composition of Manganese Nodules

Long-term mineral exposure experiments near the seafloors at two stations in the north equatorial Pacific have been designed around long-life transponders left behind after the completion of Deep Tow surveys during the October 1977 INDOMED expedition of R/V Melville for the NSFIDOE Manganese Nodule Project Attached to each transponder remaining at Site M (metalliferous rise-crest sediments; \´ N, \´ W; 3040m.) and at Site H (hemipelagic sediments; \´, \´W; 3470m.) are a dozen flow-through plastic capsules containing a variety of natural and synthetic hydrated oxides of manganese and iron, including minerals found in deep-sea manganese nodules. When the two stations are re-occupied in 1980-81, the transponders will be recalled and measurements made on materials in the capsules to determine phase changes, metal-uptake capacity, and oxidation products of the various Mn and Fe oxides.