(Table 1, page 196) Distribution of manganese nodules by size and weight in RPC-OC-76 Leg 9 Box Cores

The environmental conditions and processes that result in the origin and growth of marine manganese nodules have been of interest to both science and industry for more than 100 years, yet they are still poorly understood. The best way to investigate the significant internal features of whole nodules is to study their polished cross sections by the methods of ore microscopy. In this report, basic principles of ore microscopy are reviewed and methods of making good sections from difficult materials are described. The use of "map" photographs and mineral identification by X-ray analysis of microsamples are recommended.