TY - JOUR
T1 - Faults and their Stress Fields at the Otake-Hatchobaru Geothermal Area
AU - Hayashi, Masao
AU - Watanabe, Koichiro
AU - Furutani, Naoyuki
PY - 1985/1/1
Y1 - 1985/1/1
N2 - The strike and dip of fractures such as slickensides, hydrothermal veins and joints, found in drillcores from the Otake-Hatchobaru geothermal area have been estimated after measuring the thermoremant magnetism of the cores with an astatic magnetmeter. The results show that most of the slickensides and veins dip southward, though their strikes vary considerably from NW-SE to NE-SW. In addition, the analysis of slickensides has revealed that the NW-SE trending faults basically are of left-handed strike slip type, while the NE-SW ones are of light-handed one. It is inferred that both kinds of faults were originally formed by the ENE-WSW compressional stress fields whose minimum stress axis dip NNW with moderate angles. Recently, the normal stress fields, whose intermediate stress axis tends NW-SE, have probably made the NW-SE trending fault planes open and permeable so that they have become the present breeding faults.
AB - The strike and dip of fractures such as slickensides, hydrothermal veins and joints, found in drillcores from the Otake-Hatchobaru geothermal area have been estimated after measuring the thermoremant magnetism of the cores with an astatic magnetmeter. The results show that most of the slickensides and veins dip southward, though their strikes vary considerably from NW-SE to NE-SW. In addition, the analysis of slickensides has revealed that the NW-SE trending faults basically are of left-handed strike slip type, while the NE-SW ones are of light-handed one. It is inferred that both kinds of faults were originally formed by the ENE-WSW compressional stress fields whose minimum stress axis dip NNW with moderate angles. Recently, the normal stress fields, whose intermediate stress axis tends NW-SE, have probably made the NW-SE trending fault planes open and permeable so that they have become the present breeding faults.
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U2 - 10.11367/grsj1979.7.383
DO - 10.11367/grsj1979.7.383
M3 - Article
AN - SCOPUS:85008561987
VL - 7
SP - 383
EP - 399
JO - Journal of the Geothermal Research Society of Japan
JF - Journal of the Geothermal Research Society of Japan
SN - 0388-6735
IS - 4
ER -