1. Department of Subsurface Geobiological Analysis and ResearchJapan Agency for Marine‐Earth Science and Technology (JAMSTEC), 2‐15 Natsushim Yokosuka Kanagawa 237‐0061 Japan
2. Department of Earth Science and AstronomyThe University of Tokyo, 3‐8‐1 Komaba, Meguro‐ku Tokyo 153‐8902 Japan
3. Department of Earth ScienceUniversity of California Santa Barbara California 93106 USA
4. Spectroscopy and Imaging Division, Japan Synchrotron Radiation Research Institute, 1‐1‐1 Kouto Sayo Hyogo 679‐5198 Japan