Analysis of ferromanganese nodules, DOMES Site A, Equatorial North Pacific

This report presents the results of chemical analyses of pelagic sediment samples and associated ferromanganese nodules collected at DOMES Site A, located in the equatorial North Pacific. The samples examined in this study were taken from 7.5 cm diameter sub-cores of 66 box cores. The box cores were collected on two cruises of the R/V Oceanographer, cruises RP-23-OC77 and RP-1-OC78. Cores containing two types of sediment lithology were recovered cores containing only Quaternary sediment and those containing early Tertiary sediment overlain by 0.5 to 20 cm of Quaternary sediment. The two sediments of different age can be distinguished by their radiolarian assemblage, color, and mineralogy. The sea floor coverage of nodules tended to be lower in cores which contained Tertiary sediment than in those containing only Quaternary sediment.