TY - JOUR
T1 - Deformation path of amygdules in basic schists in Itoshima area, northern Kyushu, Japan
AU - Yamasaki, Yukiko
AU - Ikeda, Takeshi
N1 - Funding Information:
information Japan Society for the Promotion of Science, Grant/Award number: JP C25400518; Kyushu University, Grant/Award number: TK09007We would like to thank A. Yamaji and I. Shimizu for constructive reviews and Y. Tamura for editorial works. We acknowledge valued comments of F. W. Vollmer, K. Ishii, and T. Takeshita to the previous version of the manuscript. We are grateful to T. Nishiyama and T. Eguchi for their support in the preliminary field work. This study was financially supported by Takachiho scholarship of Kyushu University Grant Number TK09007 to Y. Yamasaki and the Japan Society for the Promotion of Science KAKENHI Grant Number JP C25400518 to T. Ikeda.
Funding Information:
We would like to thank A. Yamaji and I. Shimizu for constructive reviews and Y. Tamura for editorial works. We acknowledge valued comments of F. W. Vollmer, K. Ishii, and T. Takeshita to the previous version of the manuscript. We are grateful to T. Nishiyama and T. Eguchi for their support in the preliminary field work. This study was financially supported by Takachiho scholarship of Kyushu University Grant Number TK09007 to Y. Yamasaki and the Japan Society for the Promotion of Science KAKENHI Grant Number JP C25400518 to T. Ikeda.
Publisher Copyright:
© 2018 John Wiley & Sons Australia, Ltd
PY - 2018/7
Y1 - 2018/7
N2 - A deformation path of amygdules in basic schists that underwent contact metamorphism in Itoshima area, northern Kyushu, Japan, has been revealed using shape and internal microstructure of the amygdules. The amygdules are filled mainly with plagioclase that was recrystallized during the contact metamorphism. Crystal size of the plagioclase decreases with increasing aspect ratio of the amygdules. Some amygdules with low-aspect ratio contain plagioclase showing flat twin boundaries. This suggests that such amygdules were undeformed after peak of the contact metamorphism and preserved the strain accumulated until then, which probably includes prograde stage of the contact metamorphism and former regional Renge metamorphism. In contrast, the amygdules with high-aspect ratio underwent superimposition of deformation taking place after peak of the contact metamorphism. The strain analysis shows the constriction types for the former amygdules while the plane-strain types for the latter. This reveals a deformation path of the amygdules such that the constrictional strain before the peak of contact metamorphism was partially overprinted by later flattening strain, showing the apparent plane-strain types.
AB - A deformation path of amygdules in basic schists that underwent contact metamorphism in Itoshima area, northern Kyushu, Japan, has been revealed using shape and internal microstructure of the amygdules. The amygdules are filled mainly with plagioclase that was recrystallized during the contact metamorphism. Crystal size of the plagioclase decreases with increasing aspect ratio of the amygdules. Some amygdules with low-aspect ratio contain plagioclase showing flat twin boundaries. This suggests that such amygdules were undeformed after peak of the contact metamorphism and preserved the strain accumulated until then, which probably includes prograde stage of the contact metamorphism and former regional Renge metamorphism. In contrast, the amygdules with high-aspect ratio underwent superimposition of deformation taking place after peak of the contact metamorphism. The strain analysis shows the constriction types for the former amygdules while the plane-strain types for the latter. This reveals a deformation path of the amygdules such that the constrictional strain before the peak of contact metamorphism was partially overprinted by later flattening strain, showing the apparent plane-strain types.
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U2 - 10.1111/iar.12246
DO - 10.1111/iar.12246
M3 - Article
AN - SCOPUS:85044633812
VL - 27
JO - Island Arc
JF - Island Arc
SN - 1038-4871
IS - 4
M1 - e12246
ER -