(Table XIV-1, Page 137-139) Physical characteristics of manganese nodules collected in the Pacific Ocean during cruise GH76-1 of R/V Hakurei Maru

Nodule samples obtained were described and studied on board for 1) observation of occurrence and morphology in and outside samplers, size classification, measurement of weight and calculation of population density (kg/m2); 2) photographing whole nodules on the plate marked with the frames of unit areas of both 0cean-70 (0.50 m2) and freefall grab (0.13 m2), and that of typical samples on the plate with a 5 cm grid scale: 3) observation of internal structures of the nodules on cut section; and 4) determination of mineral composition by X-ray diffractometer. The relation between nodule types and geological environment or chemical composition was examined by referring to other data of related studies, such as sedimentology. acoustic survey, and chemical analysis.