Abstract
We examined the zircon U-Pb age of the following samples to constrain (1) the minimum age of sedimentation of the Tetori Group (sensu stricto) and (2) the period of deposition of the Tetori Group (s.s.) in the Jinzu Region: a tuff sample of the Hayashidani Andesite in the Hakusan Region, three samples of felsic dikes cutting the Tetori Group (s.s.) in the Hakusan and Jinzu Regions, and a tuff sample from the Tetori Group (s.s.) in the Jinzu Region. As a result, the ages of the Hayashidani Andesite and felsic dikes fell between 109 Ma and 104 Ma (middle Albian). The tuff from the Tetori Group (s.s.) in the Jinzu Region yielded the concordia age of 120.9±1.1 Ma (2σ; early Aptian), which we interpret as the age of sedimentation. Our geochronologic study, together with previous studies, suggests that the period of sedimentation of the Tetori Group (s.s.) included the early Aptian and terminated by the middle Albian. Moreover, recently reported Albian zircon fission-track ages from the Tetori Group (s.s.) are likely rejuvenation ages caused by the heat from the igneous activity that formed the felsic dikes.
Original language | English |
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Pages (from-to) | 9-26 |
Number of pages | 18 |
Journal | Memoir of the Fukui Prefectural Dinosaur Museum |
Volume | 2018 |
Issue number | 17 |
State | Published - 2018 |
Keywords
- Cretaceous
- Jinzu group
- Tetori group
- U-Pb age
- Zircon
ASJC Scopus subject areas
- Paleontology