2013 Fiscal Year Final Research Report
Volcanic activity on subducting Pacific plate with change of the stress field after an earthquake on plate boudary
| Project/Area Number |
24654180
|
|---|
| Research Category |
Grant-in-Aid for Challenging Exploratory Research
|
| Allocation Type | Single-year Grants |
|---|
| Research Field |
Geochemistry/Astrochemistry
|
|---|
| Research Institution | Tohoku University |
|---|
Principal Investigator |
HIRANO Naoto 東北大学, 東北アジア研究センター, 准教授 (00451831)
|
|---|
| Project Period (FY) |
2012-04-01 – 2014-03-31
|
| Keywords | プチスポット / 太平洋プレート / 年代測定 / 玄武岩 / 日本海溝 |
|---|
| Research Abstract |
The new kind submarine volcanoes, petit-spot, were erupted on the subducting plate, which occur in a region of the plate-flexure prior to subduction into the trench off NE Japan. Monogenetic petit-spot volcanoes located on the NW Pacific Plate are too tiny, less than 2 km in diameter, and yield eruption ages of various times during 0 to 9 Ma with three new data of Ar-Ar datings of 3.8, 6.2, and 9.2 Ma each (papers in preparation). The erupting time would be over the 0 to 10 Ma along the present plate motion, suggesting the episodic eruption of magma over a large eruption area but with low volumes of magma production. As some samples, however, are generally not used to be analyzed by sample-irradiated ArAr dating, this study adopted the U-Pb dating with the separation of zircons and apatites, awaiting for future dating results.
This study is reported by the oral presentation in JpGU 2014 Meeting, and the paper in Geochemical Journal (Hirano et al., 2013).
|
