Chemical composition of manganese nodules and crusts from the Central Pacific

Of the 26 samples collected during VA-05/1 cruise of R V Valdivia during 1972, 19 were nodules of different forms, 4 ferromanganese crusts and 3 cylindral nodules. Nodules and crusts were air dried and pulverised. In case of cylindrical-types and crust material, the clayey-calcareous filling and core materials were removed. The powder was dried at 110°C for 24 hr. Samples were digested in an autoclave 'BOMB' with a mixture of HF-HCl-HNO3. Determinations were carried out on a PE atomic absorption spectrophotometer.