Composition and genesis of zeolitic claystones from the central Indian Ocean Basin

Abstract

More than fifty indurated sediments recovered from the Central Indian Ocean Basin (CIoB) are examined during the course of collection for manganese nodules and crusts. The samples occur as slabs either over which ferromanganese oxides are present or over a substrate of altered oceanic basalt in conjunction with Palagonite or within the nucleus of manganese nodules. Mineralogically and compositionally, the samples show a mixture of phillipsite, palagonite and montmorillonite. It is suggested that the volcanogenic precursors occurring in the CIOB were subjected to varying degrees of alteration under the influence of low temperature conditions, resulting in the formation of zeolitic claystones. The CIoB samples have similarities to those reported from various sites in the world oceans