Back to Search Start Over

Structural evolution of the Nojima fault (Awaji Island, Japan) revisited from the GSJ drill hole at Hirabayashi

Authors :
Boullier, Anne-Marie
Fujimoto, Koichiro
Ito, Hisao
Ohtani, Tomoyuki
Keulen, Nynke
Fabbri, Olivier
Amitrano, David
Dubois, Michel
Pezard, Philippe
Source :
Earth, Planets and Space; December 2004, Vol. 56 Issue: 12 p1233-1240, 8p
Publication Year :
2004

Abstract

Following the Hyogoken Nanbu earthquake (January 17, 1995, Mw=7.2), three drillholes were sunk through the Nojima Fault (Awaji Island, Japan). Textural and petrographic studies of the Geological Survey of Japan (GSJ) drill cores allow recognition of two deformation episodes. The first one is older than the deposition of the Middle to Late Eocene Kobe Group, corresponds to a left-lateral movement on the Nojima fault and is expressed by pseudotachylytes, kinking of biotite crystals in the low-strain rocks and an intense laumontite hydrothermal alteration. The second one displaces the basal unconformity of the Kobe group, corresponds to a right-lateral reverse displacement and is expressed at least by carbonate-filled hydraulic fractures and thin gouge zones. Different important deformation mechanisms are recorded by the fault rocks, but questions relating to the attribution of deformation and alteration features to one or other deformation episodes remain unresolved.

Details

Language :
English
ISSN :
13438832 and 18805981
Volume :
56
Issue :
12
Database :
Supplemental Index
Journal :
Earth, Planets and Space
Publication Type :
Periodical
Accession number :
ejs33278243
Full Text :
https://doi.org/10.1186/BF03353345