Department of Earth Sciences Okayama University Okayama 700-8530 Japan;
Key-Lab for Evolution of Past Life andEnvironment MEC Jilin University Changchun 130026 China;
Paleontological Institute of Shenyang Normal University Shenyang 110034 China;
Department of Geosciences National Taiwan University Taipei 106 China;
Clay and Interface Mineralogy RWTH Aachen University Germany;
Kyoto Fission-Track Co. Ltd. 44-4 Minamitajiri-cho Omiya Kita-ku Kyoto 603-8832 Japan;