During RV SONNE cruise SO239 in March/April 2015 five sites in the area of the Clarion-Clipperton Fracture Zone (CCZ) in the eastern equatorial Pacific were visited as part of the JPI Oceans pilot action Ecological Aspects of Deep-Sea Mining“. Here, we present a comparable study on (1) the redox zonation in the sediments induced by the input flux of organic matter, (2) biogeochemical reactions including the driver of organic matter degradation and (3) diagenetic manganese redistribution and implications for manganese nodule formation