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| Titel |
The exhumation mechanism of the Yuli belt in Chinshuichi area, eastern
Center Range, Taiwan |
| VerfasserIn |
Ting-Cheng Ma, Yuan-Hsi Lee, Wei Lo, Xi-Bin Tan |
| Konferenz |
EGU General Assembly 2017
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| Medientyp |
Artikel
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| Sprache |
en
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 19 (2017) |
| Datensatznummer |
250142888
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| Publikation (Nr.) |
 EGU/EGU2017-6562.pdf |
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| Zusammenfassung |
| The continental margin of Eurasia plate subducted into Philippine Sea plate that results in
developing the high P low T Yuli belt in eastern Center Range, Taiwan. Previous
petrology studies show the Yuli belt has been subducted to ca. 50-55km in depth. In this
study we combine with structural analysis, potassic mica K-Ar dating and zircon
fission track ages to reveal the exhumation process of the Yuli belt in Chinshuichi
area.
In the Yuli belt it develops E-W trending low angle extensional ductile shear zone and the
F2 recumbent folds. Both ductile shear zone and F2 recumbent fold infer extensional
structures in deeper.
In the eastern side of the Yuli belt the youngest detrital zircon in meta-sandstone is
ca.10Ma that indicates the metamorphism and deformation should be younger than 10Ma.
The potassic mica K-Ar ages show 10-26Ma which is older than strata age indicating partial
reset ages and the oldest reset ages could be 5-8Ma. By contrast the zircon fission track
ages show quite young age 0.4-1Ma in Chinshuichi area. This indicates the cooling
rate is rather low between 8-1Ma and start to rapid cooling (260-650∘C/km) since
the 1Ma. Considering the reset temperature of zircon fission track (ca. 260∘C) is
similar with the deformation temperature of S2 (dominantly in pressure solution
crenulation cleavage) that suggests that the S2 developed since ca. 1Ma. Considering the
extensional structures are associated with rapid cooling we suggest that the E-W trending
extension is the important mechanism for exhumation the high pressure Yuli belt. |
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