| Project/Area Number |
05041054
|
|---|
| Research Category |
Grant-in-Aid for international Scientific Research
|
| Allocation Type | Single-year Grants |
|---|
| Section | Field Research |
|---|
| Research Institution | University of Tokyo |
|---|
Principal Investigator |
YONEKURA Nobuyuki Professor, Graduate School of Science University of Tokyo, 大学院・理学系研究科, 教授 (30011563)
|
|---|
| Co-Investigator(Kenkyū-buntansha) |
王 存玉 中国科学院, 地質研究所, 助教授
汪 一鵬 中国科学院, 地質研究所, 教授
どん 起東 中国科学院, 地質研究所, 教授
SUZUKI Yasuhiro Lecturer, Faculty of Letters Aichi Prefectural University, 文学部, 講師 (70222065)
TAKEUCHI Akira Associate Professor, Faculty of Science Toyama University, 理学部, 助教授 (20126494)
DENG Qidong Professor, Institute of Geology Academia Sinica
WANG Yipeng Professor, Institute of Geology Academia Sinica
WANG Cunyu Associate Professor, Institute of Geology Academia Sinica
蘇 宗正 中国科学院, 地質研究所, 教授
〓 起東 中国科学院, 地質研究所, 教授
|
|---|
| Project Period (FY) |
1993 – 1994
|
| Project Status |
Completed (Fiscal Year 1994)
|
| Budget Amount *help |
¥9,000,000 (Direct Cost: ¥9,000,000)
Fiscal Year 1994: ¥4,500,000 (Direct Cost: ¥4,500,000)
Fiscal Year 1993: ¥4,500,000 (Direct Cost: ¥4,500,000)
|
|---|
| Keywords | active faults / seismotectonics / Shanxi graben system / China / Quaternary / basalt volcanism / Datong Basin / 東アジア / 地震断層 / 大地震 / 火山活動 / 山西地溝帯 |
|---|
| Research Abstract |
We investigated active tectonic features of the Datong and Yanyuan Basins in the northernmost part of the Shanxi graben system of North China to clarify the seismotectonics of the region. The Shanxi graben system is one of the most outstanding Pliocene-Quaternary graben systems and of large earthquake belts in China. The Shanxi graben system extends as a series of en echelon left-stepping asymmetrical half-graben basins on the Shanxi Highlands over a distance of more than 1200 km. It extends as a sinuous S-shaped curve with a NNE-trending transtensional segment in the middle, and NE to ENE-trending extensional domains on both terminal segments. The extensional domains on both terminal segments are characterized by the ENE-trending normal faulting and basin-and-range structures. The Quaternary basalt erupted in the northern extensional domain during the Pleistocene and their volcanic cones are distributed in the Datong Basin.
The northern piedmont fault of the Liuleng Mountains which del
… More
ineates the southern margin of the Datong and Yanyuan Basins extends about 150 km. The fault is dip-slip normal and has been active in the Quaternary. Although nor historical earthquakes were recorded before 1989, earthquake swarms occurred in October 1989 (Ms=6.1in maximum) and March 1991 (Ms=5.8 in maximum) in the Datong Basin.
The northern piedmont fault of the Liuleng Mountains is dip-slip normal and divided into 4 or 6 segments of 10-15 km long for each. The easternmost segment consists of two fault lines which run parallel to the mountain front. The fault located along the mountain front is inactive in the latest Quaternary, instead the fault newly formed in the basin floor is active. The average vertical slip rate is calculated as 0.4-0.7 m/ka during the latest Quaternary on the basis of the amount of the deformation on the dissected alluvial fans and their formative ages of TL dates. The latest event of faulting (that is the occurrence of large earthquake with surface rupture) is estimated between 1,500 yBP and 7,600 yBP and no event is estimated between 13,000 yBP and 19,000 yBP.This suggests that the recurrence interval of the faulting (=large earthquake) is likely no less than 6,000 yrs.
Volcanic vents associated with fissure eruptions of younger basalt (estimated as late Quaternary) extend about 1 km in 70 degree ENE.This alignment is harmonious with the trend of normal faulting and is perpendicular to the regional principal extensional axis from NNW to SSE. Less
|
