[1
]Department of Geology and Paleontology; National Museum of Nature and Science; 3-23-1
Hyakunin-cho, Shinjyuku-ku,; Tokyo; 169-0073; Japan
[2
]Institute for Research on Earth Evolution; Japan Agency of Marine-Earth Science and
Technology; 2-15 Natsushima-Cho, Yokosuka,; Kanagawa; 237-0061; Japan
[3
]Lamont-Doherty Earth Observatory; Columbia University; 61 Route 9W,; Palisades; New
York; 10964; USA
[4
]Institute of Geology and Geoinformation; Geological Survey of Japan, AIST; Tsukuba
Central 7, 1-1-1 Higashi,; Tsukuba; 305-8567; Japan