Authigenic todorokite and phillipsite inside deep-sea manganese nodules

Phillipsite and todorokite assemblages are observed by scanning electron microscopy to line cavities and voids adjacent to areas where extensive leaching of biogenic siliceous debris has occurred inside deep-sea manganese nodules. Clusters of todorokite crystallites containing Ni and Cu also fill fissures, coat biogenic debris, and infill voids where biogenic debris once occurred in interiors of the nodules. We suggest that the post-depositional growth of phillip-site and conversion of δ-MnO₂ to todorokite inside manganese nodules is promoted by the dissolution of biogenic siliceous debris.