(Table 1, page 215) Chemical composition Mn deposits from the Southern Oceans around Antarctica

An extensive deposit of ferromanganese concretions has been investigated in the Southern Ocean around Antarctica, a region of particular interest in that it contains most of the parameters thought to be of importance in concretion formation. The physical and chemical properties of 93 concretions from 62 stations have been analyzed for possible interpretations as to the elemental source and the distributional characteristics as possible responses to respective parameters. It was found that four classes of concretionary types best represent the physical characteristics of concretions recovered within this area and that their morphology may be representative of the rate of formation and the proximity to the source of elemental constituents. It is suggested that the major source of concentrated elements in Southern Ocean ferromanganese concretions is submarine volcanism, with the dominant volcanism occurring along the Pacific-Antarctic Ridge. There is some evidence that connects periodic concretion growth and distribution characteristics to possible glacial and inter-glacial periods.