| Project/Area Number |
18H01311
|
|---|
| Research Category |
Grant-in-Aid for Scientific Research (B)
|
| Allocation Type | Single-year Grants |
|---|
| Section | 一般 |
|---|
| Review Section |
Basic Section 17040:Solid earth sciences-related
|
|---|
| Research Institution | Kyoto University |
|---|
Principal Investigator |
|
|---|
| Co-Investigator(Kenkyū-buntansha) |
堤 昭人 京都大学, 理学研究科, 准教授 (90324607)
|
|---|
| Project Period (FY) |
2018-04-01 – 2021-03-31
|
| Project Status |
Completed (Fiscal Year 2021)
|
| Budget Amount *help |
¥17,420,000 (Direct Cost: ¥13,400,000、Indirect Cost: ¥4,020,000)
Fiscal Year 2020: ¥4,160,000 (Direct Cost: ¥3,200,000、Indirect Cost: ¥960,000)
Fiscal Year 2019: ¥5,590,000 (Direct Cost: ¥4,300,000、Indirect Cost: ¥1,290,000)
Fiscal Year 2018: ¥7,670,000 (Direct Cost: ¥5,900,000、Indirect Cost: ¥1,770,000)
|
|---|
| Keywords | 熱年代学 / 東北日本弧 / 隆起-削剥 / フィッショントラック / (U-Th)/He / 隆起-侵食 |
|---|
| Outline of Final Research Achievements |
Recent progress of low-temperature thermochronology, e.g., developments of (U-Th-Sm)/He method and fission-track inversion modeling, enables to analyze uplift-denudation-cooling histories of the island-arc mountains with good confidence. This is particularly fruitful for studying the topographic evolution of the Japan Arc, because many of the Japanese mountains are started to uplift in recent time (e.g., late Pliocene to Quaternary) and hence the resultant smaller amount of total denudation is only resolvable by low-temperature thermochronology. We conducted (U-Th-Sm)/He and fission-track analyses of the NE Japan Arc, and found following cooling episodes: (1) >40Ma in the forearc, (2) ~10- 5Ma in the backarc, and (3) ~1-2Ma in the central Ou backbone range, with younging towards the central axis. These results suggest contrasting uplift-denudation-cooling histories among the regions, and implies the doming uplift of the Ou backbone range.
|
| Academic Significance and Societal Importance of the Research Achievements |
現在の固体地球テクトニクス研究の最前線は、プレート縁辺部の変形における地震サイクルより長い時間スケールにおける非弾性成分の推定にある。そのためには、時間スケールの異なる様々な手法を用いて地殻変動の時空間分布を確立することが強く求められる。そこで鍵の一つとなるのが陸域の隆起－削剥速度の時空間変動であり、我々のグループは日本列島をはじめとする島弧において熱年代学を用いた組織的な研究に着手した。まず、代表的な島弧である東北日本孤について、隆起－削剥－冷却史の全体像を初めて明らかにした。特に、北上山地と奥羽脊梁山脈について稠密な熱年代データが得られ、ドーム状隆起などのモデル検証を進めることができた
|
