The origin of manganese nodules on the ocean floor

Abstract

Manganese oxide minerals occur on the ocean floor as concretions, crusts, and as fine disseminations in sediments. Nodules studied have palagonitic cores, which, themselves, contain segregations of ferro-manganese oxides. Association of nodules with phillipsite and montmorillonitic clay, regarded as alteration products of palagonite, suggests a genetic relation of nodules to basic submarine volcanism. Acid solutions produced by mingling of sea water and basic magma may leach out and concentrate manganese. Sea water, continually entering the system, may cause neutralization and oxidation resulting in precipitation of manganese oxides. Minor elements concentrated with manganese may also be of volcanic origin.