Trace element investigations of manganese nodules, sediments and pore waters using neutron activation analysis - a contribution to the study of manganese nodules genesis

Manganese nodules, the underlying sediments and its pore waters were collected in the Pacific south east of Hawaii during the voyage VA 13/1 of the German research vessel VALDIVIA in January 1976. The concentrations of the metals iron, cobalt, nickel, manganese, copper and other trace elements are determined. Applying the method of neutron activation analyis (NAA) up to 50 elements can be analysed. The activation is done in the research reactor at Geesthacht. The investigations give a constribution to the research work done for clearing up the correlations between the chemical composition of the nodules, the sediments, the pore waters and the waters near the sea bottom. For a better understanding of the nodule growth detailed determinations of the contents of major and minor elements in the nodules depending on the position of the nodules on or in the sediment must be conducted. The upper side of the nodule turned to the sea water and the lower side lying on the sediment are analysed separately. The results are compared to the elemental composition of the sea water and the pore water. The trace element pattern in the different layers of the nodule can serve to answer the question whether the pore water or the sea water offers the better conditions for the nodule growth. A comparison of the results to those of the element determinations in waters of the sea bottom and of pore waters from the VALDIVIA journeys VA 04 and VA 05 in 1972 and 1973 is given. (orig.)