We thank the scientific and technical crew of Leg 207 for support during onboard sampling and R. Kort ( Oldenburg) for technical support during SEM measurements. This research used samples and data provided by the Ocean Drilling Program (ODP). ODP is sponsored by the U.S. National Science Foundation (NSF) and participating countries under management of Joint Oceanographic Institutions (JOI), Inc. Research was funded by Deutsche Forschungsgemeinschaft (grants BO 1584/2-1,2 and BR 775/16-1,2 and 17-1,2) and Max Planck Society, Germany. Work on sediments from the Black Sea was funded by Deutsche Forschungsgemeinschaft to MEB and BBJ during DFG-SPP (RV Meteor cruise M51-4; grant JO 307/6-1). M.E. Böttcher wishes to thank E. Clapton, R. Gilbert, G. Harrison, and J. Lennon for their influence on the atmosphere during manuscript preparation. The manuscript is dedicated to E.O. Böttcher on the occasion of his 80th birthday. Constructive comments by editor M. Malone, reviewer T.J. Algeo, and an anonymous reviewer helped to improve the manuscript.