TY - JOUR
T1 - K-Ar ages determined for post-caldera volcanic products from Aso volcano, central Kyushu, Japan
AU - Miyoshi, Masaya
AU - Sumino, Hirochika
AU - Miyabuchi, Yasuo
AU - Shinmura, Taro
AU - Mori, Yasushi
AU - Hasenaka, Toshiaki
AU - Furukawa, Kuniyuki
AU - Uno, Koji
AU - Nagao, Keisuke
N1 - Funding Information:
We express our gratitude to Prof. K. Takemura for his support throughout this study. We are grateful to Prof. Shan de Silva for his helpful comments and critical suggestions on this manuscript. We are also grateful to Prof. Joan Marti for the efficient editorial handling. This work has been supported in part by a grant from the Ministry of Economy, Trade and Industry (METI) to M. Miyoshi in 2010.
PY - 2012/6/1
Y1 - 2012/6/1
N2 - We determined the K-Ar ages for post-caldera lavas from Aso volcano in central Kyushu, Japan using the unspiked sensitivity method. The following three peaks of highly-frequent volcanism are recognized in the post-caldera stage: 70-50. ka, 40-20. ka and later than 10. ka. The two peaks of 70-50. ka and 40-20. ka are characterized by activities of compositionally diverse magmas from basalt to rhyolite. The volumes of silicic magmas are significantly larger than those of basalt magmas in these peaks. On the other hand, the peak later than 10. ka is characterized by predominantly basaltic eruptions without silicic magma activities. The active center of the silicic magma production (=. crustal assimilation of injected basalt) had presumably migrated northeastward from the southwestern part of the caldera between the peaks of 70-50. ka and 40-20. ka. The predominant basaltic activity in the peak later than 10. ka represents that the production rate of silicic magma decreased, and does not indicate the accumulation of voluminous silicic magma beneath the recent Aso caldera.
AB - We determined the K-Ar ages for post-caldera lavas from Aso volcano in central Kyushu, Japan using the unspiked sensitivity method. The following three peaks of highly-frequent volcanism are recognized in the post-caldera stage: 70-50. ka, 40-20. ka and later than 10. ka. The two peaks of 70-50. ka and 40-20. ka are characterized by activities of compositionally diverse magmas from basalt to rhyolite. The volumes of silicic magmas are significantly larger than those of basalt magmas in these peaks. On the other hand, the peak later than 10. ka is characterized by predominantly basaltic eruptions without silicic magma activities. The active center of the silicic magma production (=. crustal assimilation of injected basalt) had presumably migrated northeastward from the southwestern part of the caldera between the peaks of 70-50. ka and 40-20. ka. The predominant basaltic activity in the peak later than 10. ka represents that the production rate of silicic magma decreased, and does not indicate the accumulation of voluminous silicic magma beneath the recent Aso caldera.
KW - Aso volcano
KW - K-Ar dating
KW - Post-caldera volcanism
KW - Sensitivity method
UR - http://www.scopus.com/inward/record.url?scp=84860292567&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84860292567&partnerID=8YFLogxK
U2 - 10.1016/j.jvolgeores.2012.04.003
DO - 10.1016/j.jvolgeores.2012.04.003
M3 - Article
AN - SCOPUS:84860292567
VL - 229-230
SP - 64
EP - 73
JO - Journal of Volcanology and Geothermal Research
JF - Journal of Volcanology and Geothermal Research
SN - 0377-0273
ER -