日本地球惑星科学連合2018年大会

講演情報

[JJ] Eveningポスター発表

セッション記号 S (固体地球科学) » S-CG 固体地球科学複合領域・一般

[S-CG63] 地球惑星科学におけるレオロジーと破壊・摩擦の物理

2018年5月20日(日) 17:15 〜 18:30 ポスター会場 (幕張メッセ国際展示場 7ホール)

コンビーナ:桑野 修(国立研究開発法人 海洋研究開発機構)、清水 以知子(東京大学大学院理学系研究科地球惑星科学専攻)、石橋 秀巳(静岡大学理学部地球科学専攻、共同)、田阪 美樹(島根大学)

[SCG63-P05] Mechanism of high porosity anomaly development at Kazusa fore-arc basin Formation, Japan: implication for pore pressure evolution model in fore-arc basin

*上原 真一1丸茂 春菜1金子 幸代1 (1.東邦大学理学部)

キーワード:間隙圧異常、前弧海盆、上総層群、圧密

To investigate mechanisms of over-pressurization in sedimentary basins is important for understanding properties of fluid circulations, and/or developments of resources at sedimentary basins. It has been reported that there are high porosity anomaly has been reported at the Kazusa fore-basin Formation, Boso peninsula, NE Japan, which is possibly because of over-pressurization. Marumo (2015, Master thesis) examined how pore pressure develops in silt/mudstone layer which has hydraulic properties similar to those in the Kazusa Formation simply by sedimentation and consolidation of the layer, and indicated that this simple pore pressure development model can be one of the candidates for mechanisms of the high porosity anomaly development at the Kazusa Formation. We develop the model of Marumo (2015) by including more realistic conditions such as sedimentation, subsiding and uplifting history for the Kazusa Formation, and examine the mechanism of the high porosity anomaly development and the pore pressure development evolutions.