1. Institute of Geology and Geoinformation; Geological Survey of Japan; National Institute of Advanced Industrial Science and Technology; Central 7; 1-1-1 Higashi; Tsukuba; Ibaraki; 305-8567; Japan
2. Graduate School of Engineering and Resource Science; Akita University; 1-1 Tegata-gakuen-machi; Akita city; Akita; 010-8502; Japan
3. National Institute of Polar Research; 10-3 Midoricho; Tachikawa; Tokyo; 190-8518; Japan
4. Geological Museum; Geological Survey of Japan; National Institute of Advanced Industrial Science and Technology; Central 7; 1-1-1 Higashi; Tsukuba; Ibaraki; 305-8567; Japan
5. Department of Earth and Planetary Sciences; Kyusyu University; 6-10-1 Hokazaki; 10 Higashi-ku; Fukuoka; 812-8581; Japan
6. Institute of Earth and Environmental Science; University of Potsdam; Karl-Liebknecht Str.; Potsdam; Golm; 14476; Germany