Catalog for late quaternary marker-tephras in japan ii : tephras occurring in northeast honshu and hokkaido
スポンサーリンク
概要
- 論文の詳細を見る
A catalog for late Quaternary marker-tephras occurring in northern Japan is presented. Characterization of tephras for identification is based on a combination of their features. Stratigraphic and petrographic descriptions are indispensable in correlation of distal tephras with proximal ones. As a result of characterization of tephras in northern Japan, a number of tephra layers spread over extensive areas were disclosed. Of the eight widespread tephras, one was supplied from Korean Peninsula, two from Kyushu and others from northern Japan. Most of such tephras were produced by gigantic plinian, phreatoplinian and/or coignimbrite ash-forming eruptions, and are favorable for establishing a Quaternary chronology around northern Japan. These discoveries further encouraged identification and correlation of the following four plinian and phreatoplinian widespread tephras in Hokkaido. (1) Kutcharo-Shoro ash: ejected from phreatoplinian eruptions of the Kutcharo caldera ca. 30-32 ka; associated with pyroclastic flow deposits assigned to the Kutcharo pumice flow deposit-I previously defined around the caldera. (2) Zenikame-Menagawa pumice: produced from the submerged crater 2 km off the east coast of Hakodate ca. 35 ka; correlated with the previously defined tephras, Hidaka pumice and Rakko pumice-1 in the Hidaka and Tokachi districts. (3) Kuttara-Mukawa pumice: produced from the Kuttara caldera ca. 60 ka; associated with pyroclastic flow deposits; correlated with such tephras as Mukawa pumice-3, Rakko pumice-IV and Orange pumice-3 in the southern Ishikari and Tokachi districts. (4) N, Us-c pumice: possibly ejected from the Kuttara caldera ca. 60-70 ka; covering E-W elongated areas from the Usu-Kuromatsunai to Ishikari-Tokachi-Kushiro districts.
- 首都大学東京の論文
首都大学東京 | 論文
- シンガポールの中国政策
- フランスにおける社会保障給付と内外人平等原則(二・完) : 無拠出給付に焦点をあてて
- フランスにおける社会保障給付と内外人平等原則(一) : 無拠出給付に焦点をあてて(渕倫彦教授退職記念論文集)
- 1999年度社会福祉基礎ゼミ(後期)の評価
- 生活時間と介護の社会化