TY - JOUR
T1 - Widespread tephras in sediments from lake Ichi-no-Megata in northern Japan
T2 - Their description, correlation and significance
AU - Okuno, Mitsuru
AU - Torii, Masayuki
AU - Yamada, Kazuyoshi
AU - Shinozuka, Yoshitsugu
AU - Danhara, Tohru
AU - Gotanda, Katsuya
AU - Yonenobu, Hitoshi
AU - Yasuda, Yoshinori
N1 - Funding Information:
The authors thank Isamu Ono, Masahiro Masuya and Kazuya Suganuma (Akita prefectural government), Matsuo Amemiya and Yasuyuki Aoyama (Mogami Kosho Ltd.) and Okuyama Boring Co. Ltd. for their help in coring Lake Ichi-no-Megata. We also thank Associate Prof. Kazuhiro Toyoda and Akane Umezu (Hokkaido University), Taisuke Nishikawa (Osaka City University), Masaki Kamite (Tokyo Metropolitan University), Dr. Hiroo Nasu (The Graduate University for Advanced Studies), Dr. Toshiyuki Fujiki (International Research Center for Japanese Studies) and Takeshi Takeda (free cameraman) for their help in coring and sampling. We thank to Prof. Tadao Nishiyama and Associate Prof. Hiroshi Isobe (Kumamoto University) for supporting the EDS analysis. This study was partly supported by the Ministry of Environments (2006) , Akita Prefecture (2006-2007) and grant-aid for Scientific Research (Nos. 18100007 and 21101002 ) from Ministry of Education, Culture, Sports, Science and Technology , Japan, and the Tokyo Foundation (the project of Civilization and Environment) . We are grateful to Dr. Ma Hannah T Mirabueno (the Philippine Institute of Volcanology and Seismology) and Dr. Hanako Domitsu (the University of Shiga Prefecture) for their useful comments for early version of the manuscript. We are very grateful to Dr. Stephen C. Kuehn, an anonymous reviewer and Dr. Nicholas J.G. Pearce for their valuable comments on the manuscript. We would like to dedicate this paper to the late Professor Shinji Nagaoka of Nagasaki University for his encouragement.
PY - 2011/12/20
Y1 - 2011/12/20
N2 - Lake Ichi-no-Megata is a maar in the Oga Peninsula, which is connected with the western side of Honshu Island, NE Japan. A 37-m long sediment core (IMG06) obtained from the center of the lake contains five fine ash layers. Stratigraphic positions in the core provide ages of five ashes to be 30, 21, 17, 7.3, and 1.0 cal ka BP, respectively. These layers are correlated with Aira-Tn (AT), Daisen-Kusatanihara (D-KsP), Asama-Kusatsu (As-K), Kikai-Akahoya (K-Ah) and Baitoushan-Tomakomai (B-Tm) tephras in ascending order, based on stratigraphy and petrographic characteristics such as grain assemblages, refractive indices, and major element compositions of glass shards. Although the AT, K-Ah and B-Tm tephras have been well known as widespread tephras, this study finds that the D-KsP, As-K and K-Ah tephras have more extensive distributions than the previous studies estimated. The D-KsP and As-K tephras have the potential to become useful time-markers in and around the Sea of Japan between the AT and K-Ah tephras.
AB - Lake Ichi-no-Megata is a maar in the Oga Peninsula, which is connected with the western side of Honshu Island, NE Japan. A 37-m long sediment core (IMG06) obtained from the center of the lake contains five fine ash layers. Stratigraphic positions in the core provide ages of five ashes to be 30, 21, 17, 7.3, and 1.0 cal ka BP, respectively. These layers are correlated with Aira-Tn (AT), Daisen-Kusatanihara (D-KsP), Asama-Kusatsu (As-K), Kikai-Akahoya (K-Ah) and Baitoushan-Tomakomai (B-Tm) tephras in ascending order, based on stratigraphy and petrographic characteristics such as grain assemblages, refractive indices, and major element compositions of glass shards. Although the AT, K-Ah and B-Tm tephras have been well known as widespread tephras, this study finds that the D-KsP, As-K and K-Ah tephras have more extensive distributions than the previous studies estimated. The D-KsP and As-K tephras have the potential to become useful time-markers in and around the Sea of Japan between the AT and K-Ah tephras.
UR - http://www.scopus.com/inward/record.url?scp=81255188785&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=81255188785&partnerID=8YFLogxK
U2 - 10.1016/j.quaint.2011.08.015
DO - 10.1016/j.quaint.2011.08.015
M3 - Article
AN - SCOPUS:81255188785
VL - 246
SP - 270
EP - 277
JO - Quaternary International
JF - Quaternary International
SN - 1040-6182
IS - 1-2
ER -