2013 Fiscal Year Final Research Report
Assessment of fault activity by direct dating of fault gouge
| Project/Area Number |
23710204
|
|---|
| Research Category |
Grant-in-Aid for Young Scientists (B)
|
| Allocation Type | Multi-year Fund |
|---|
| Research Field |
Natural disaster science
|
|---|
| Research Institution | National Institute of Advanced Industrial Science and Technology (2012-2013)
Japan Atomic Energy Agency (2011) |
|---|
Principal Investigator |
YAMASAKI Seiko 独立行政法人産業技術総合研究所, 地質情報研究部門, 研究員 (90555236)
|
|---|
| Project Period (FY) |
2011 – 2013
|
| Keywords | 活断層 / 粘土鉱物 / 年代測定 |
|---|
| Research Abstract |
Recent studies highlighted the potential to determine the age of faulting by using K-Ar dating of clay minerals in fault zone. However, the challenge remains difficult due to the possibility of contamination by old K-bearing minerals of the host rock.
In order to establish a direct dating method for clay minerals in fault zone, precise clay separation combined with mineral characterization of fault gouge samples, and dating by unspiked K-Ar method was conducted. The finer fractions yield younger K-Ar ages, and contain larger amount of low-temperature type clay, suggesting enrichment in more recently grown clay minerals. Because K-Ar dating cannot detect no-potassium clay which formed <100 degree C, the ages mean the latest timing of faulting under >100 degree C temperature environment. Further fundamental studies about fault clay and requirements in dating are needed.
|
