The authors are thankful to Jutta Heinze and Barbara Valbonesi for their support with sample preparation and XRD analyses. Petra Gloer assisted with electron microprobe measurements at GEOMAR. Isotope analyses were handled very capably by Michael Joachimski at the Geological Institute Erlangen (C and O) and Paul Fullagar at UNC (Sr). We would also like to thank William Showers at North Carolina State University for use of his stable isotope laboratory for sample preparation and analysis. We are grateful for the comments provided by Ryo Matsumoto and Yutaka Yanagimoto, which improved the manuscript. Financial support for this work was provided by the Deutsche Forschungsgemeinschaft (DFG grant Bo 1049/4), and a JOI/USSAC Ocean Drilling Fellowship for NMR.