Chemical composition of three manganese nodules from the Pacific Ocean

Three manganese nodules from the Pacific Ocean have been analysed for 35 elements by using ma.inly spectrophotometric a.nd spectrogra.phic methods. Cu, Co, Ni, Zn, a.nd Pb were found in a.mounts approaching 1 °lo, which fa.r exceeds their average concentrations in igneous rocks. On the other hand, elements having readily hydrolyse.hie ions, such a.a Ga, Sc, Zr, Y, La and Ti, are present only in a.mounts compe.ra.ble with their concentrations in igneous rocks. Sb, Bi, Be, a.nd Cr were not detected. The hydrochloric acid-insoluble fraction of nodules is practically free of the heavy metals that are characteristic of the acid-soluble fraction; it consists principally of clay minerals, together with lesser a.mounts of quartz, apatite, biotite a.nd sodium a.nd potassium felspars.