The Stratigraphy and Paleoenvironmental Reconstruction of the Late Pleistocene Deposits in Kashiwazaki Plain, Niigata Prefecture.

スポンサーリンク

概要

• 論文の詳細を見る

• The middle-late Pleistocene deposits composed of the Yasuda Formation, the Ominato sand bed, and the Banjin sand bed were formed at Kashiwazaki Plain in Niigata prefecture. Clarifying their stratigraphy and sedimentary environment is very important for revealing the paleoenvironment during the late Pleistocene in the Kashiwazaki Plain.The Yasuda Formation is divided into an upper and a lower part. Both parts were formed with the character of valley fills because of a marin transgression under fresh or brackish water conditions in a bay which was separated from the open sea. The terrace surface of the upper part of the Yasuda Formation is correlative with the Shimosueyoshi surface in the south Kanto region.The Ominato sand bed, newly named in this paper, comprises littoral or neritic sands, which cover the lower part of the Yasuda Formation conformably. The Nakago pumice layer (ca. 150-130ka) is intercalated near the boundary between the uppermost part of the Ominato sand bed and the Banjin sand bed, composed of eolian sands which cover the Ominato sand bed comformably. From to this it is inferred that the surface of the Ominato sand bed below emerged with the Yasuda terrace at the Shimosueyoshi stage; in addinon, the Ominato sand bed and upper part of the Yasuda Formation are heterotopic facies. Under the influence of the paleoenvironment, the bar which consisted the Ominato sand bed was formed in front of Kashiwazaki Plain and the upper part of the Yasuda Formation was deposited in the lagoon behind the bar at the Shimosueyoshi transgression stage. This suggests that a barrier system was present at that stage.There existed a bar at the beginning of the regression. Because of the regression, the lagoon dried up and formed the Yasuda surface. After the Yasuda Formation and the Ominato sand bed emerged, the Banjin sand bed which was composed of eolian sands was deposited at the Shimosueyoshi stage; the Obaradai stage and the other regression stages emerged later. The Old Dune sand has remained for almost fifty thousand years.

• 日本第四紀学会の論文

著者

• 岸 清

  東京電力(株)

• 宮脇 明子

  (株)アイ・エヌ・エー

• 宮脇 理一郎

  (株)アイ・エヌ・エー

関連論文

• 2000年鳥取県西部地震震源域の活断層調査
• 古くからサイトごとに地震動評価を行ってきた原子力発電所の耐震設計法 高精度で実施される活断層評価
• 新潟県柏崎平野における上部更新統の層序と古環境の復元
• 断層ガウジ及び火山灰を用いたESR年代測定と石英粒子表面構造観察
• 第90代土木学会会長 岸さんに聞く、土木学会、土木技術者への期待
• 土木界をより知ってもらうために : 土木学会の情報発信改革
• 新年を迎えて
• 第80代土木学会会長故名誉会員藤井敏夫氏のご逝去を悼む
• 我が国のエネルギー問題と土木工学(第33回地盤工学研究発表会)
• 人工軟岩材料の開発
• The Stratigraphy and Paleoenvironmental Reconstruction of the Late Pleistocene Deposits in Kashiwazaki Plain, Niigata Prefecture.
• 1209 人口軟岩材料の開発(新素材)

もっと見る 閉じる

スポンサーリンク