Title of article :
Water-weakened lower crust and its role in the concentrated deformation in the Japanese Islands
Author/Authors :
Iio، نويسنده , , Yoshihisa and Sagiya، نويسنده , , Takeshi and Kobayashi، نويسنده , , Yoji and Shiozaki، نويسنده , , Ichiro، نويسنده ,
Issue Information :
روزنامه با شماره پیاپی سال 2002
Pages :
9
From page :
245
To page :
253
Abstract :
The nature and origin of the concentrated deformation zone along the Japan Sea coast (NKTZ: Niigata–Kobe tectonic zone) was investigated by carefully analyzing the GPS data and qualitatively modeling the lower crust in NKTZ. It was concluded that this deformation zone is not a plate boundary between the Amurian plate (AMU) and the North America plate but is rather an internal deformation zone near the eastern margin of AMU. The data previously obtained on the conductivity anomalies in the lower crust and the 3He/4He ratios suggest that the concentrated deformation in NKTZ results from the lower crust in NKTZ being weakened by a high water content. The high water content is thought to result from the dehydration of subducting slabs. NKTZ has a higher water content in the lower crust than other regions do because there is no Philippine Sea plate (PHS) seismic slab beneath NKTZ. In other regions, it is estimated that the mantle wedge above the seismic Philippine Sea slab prevents the water dehydrated from the slab from rising to the lower crust, and that the lithosphere within PHS itself prevents the water dehydrated from the Pacific plate from rising up through it.
Keywords :
Lower crust , earthquakes , intraplate processes , faults , dehydration , Ductile Deformation
Journal title :
Earth and Planetary Science Letters
Serial Year :
2002
Journal title :
Earth and Planetary Science Letters
Record number :
2322529
Link To Document :
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