ボーリング調査で明らかになった丹那盆地の変形構造
スポンサーリンク
概要
- 論文の詳細を見る
Tanna basin is one of tectonic depressions caused by the downwarping of the western slopes of Taga and Yugawara volcanoes in the northern part of Izu peninsula. Owing to this movement, the thick accumulation of sediment has filled up this basin during the late Quaternary. The Tanna fault that caused the 1930 Kita-Izu Earthquake (M 7.3) traverses this basin in N-S direction and has displaced the sediment with left lateral slip. The subsurface information of this basin gives us data on the geological history of the basin and the tectonic features of the fault since the late Pleistocene.<BR>In December 1980, Geological Survey of Japan carried out the drilling investigation in the northern part of Tanna basin to get the stratigraphical and tectonic information of the basin fill sediment. Four borings of 20 m depth were made at intervals of 20m along the nearly E-W direction so as to cross the fault trace. Obtained core samples were investigated thoroughly from the stratigraphical, chronological and paleoecological view point.<BR>As a result, it is revealed that the sediment to the depth of 20 m below the basin surface accumulated during the last 20, 000 years. And it is also found that the sediment has suffered from the small scale deformation of pressure ridge shape, as shown in Fig. 6, by the movement of the Tanna fault. However, such deformation was not observed from the geological section along the railway tunnel which penetrates into the volcanic rocks just below Tanna basin. It is thought that the small scale deformation is only a local disturbance limited to the upper horizon of the basin fill sediment and has no relation to the structure of the basin.<BR>Throughout these studies, it is revealed that the deformation in Tanna basin is composed of two different scale deformations associated with the fault movement during late Quaternary period. The larger one is the downwarping of a few kilometers in extent and the smaller one is the pressure ridge of a few tens meters in width in the upper part of the basin fill sediment.
- 社団法人 東京地学協会の論文
著者
関連論文
- 新富士火山初期の大きなソレアイトマグマだまりにおける結晶分化(火山のモデル(II))
- 愛媛県西条市における中央構造線岡村断層のトレンチ発掘調査
- 糸魚川 - 静岡構造線活断層系の最近の断層活動 - 牛伏寺断層・松本市並柳地区トレンチ発掘調査 -
- 64. 大分層群中の火砕流堆積物について(日本火山学会1986年度秋季大会)
- 64 大分層群中の火砕流堆積物について
- 南関東の地震テクトニクスと国府津・松田断層の活動
- 25年後, 地質学は未来を予測する科学になる
- 1896年陸羽地震の地震断層
- 活断層のトレンチ発掘調査
- 活断層からみた南部フォッサマグナ地域のネオテクトニクス (南部フォッサマグナ・フィリピン海プレ-ト北縁のネオテクトニクス)
- 立川断層とその第四紀後期の運動
- 106. 福井県三方五湖の表層堆積物の層相と地殻変動との関係
- ボ-リング調査で明らかになった丹那盆地の変形構造
- 62A. 古富士および新富士火山噴出物の微量元素(日本火山学会1989年春季大会)
- 235 富山トラフの第四紀地殻変動 : 「しんかい2000」による潜航調査の成果
- 62A 古富士および新富士火山の噴出物の微量元素
- ボーリング調査で明らかになった丹那盆地の変形構造
- 活断層からみた南部フォッサマグナ地域のネオテクトニクス (南部フォッサマグナ・フィリピン海プレ-ト北縁のネオテクトニクス)
- 立川断層とその第四紀後期の運動
- 鎌倉市長谷小路周辺遺跡の液状化跡
- Trenching Study of Okamura Fault of the Median Tectonic Line Active Fault System at Saijo in August, 1988
- 1990 Trenching Study of the Gofukuji Fault of the Itoigawa-Shizuoka Tectonic Line Active Fault System at Namiyanagi, Matsumoto, Central Japan