Processes of formation and compsitional variability of hydrogenetic ferromanganese crusts, NW Pacific seamounts

Abstract

The first attempt of systematic mapping and in-situ observations and measurements of hydrogenetic ferromanganese crusts using ROV (Hyper Dolphin, JAMSTEC) , indicated ubiquitous occurrence of thick layers of crusts over the outcrops on the slope of a seamount in the waterdepth range between 1000 and 3000 meters. The radiochemical dating by Be-isotopes and geochemical and mineralogical characteriztiton suggests a waterdepth dependent pattern in chemistry that may lead possible ocean-scale correlations.