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Fission track dating of faulting events accommodating plastic deformation of biotites
Author(s) -
Sueoka S.,
Shimada K.,
Ishimaru T.,
Niwa M.,
Yasue K.,
Umeda K.,
Danhara T.,
Iwano H.
Publication year - 2017
Publication title -
journal of geophysical research: solid earth
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.983
H-Index - 232
eISSN - 2169-9356
pISSN - 2169-9313
DOI - 10.1002/2016jb013522
Subject(s) - geology , biotite , fission track dating , basalt , dike , apatite , intrusion , closure temperature , geochemistry , fault (geology) , seismology , mineralogy , petrology , zircon , paleontology , quartz
We performed fission track (FT) analyses to constrain the timing of fault slip events associated with plastic deformation of biotite grains formed at high temperature, higher than 200–300°C. Apatite FT ages of 49.6–16.7 Ma were obtained from Late Cretaceous granites near the fault, with younger ages near a basaltic dike that intruded at ~19 Ma. By comparing the distribution of apatite FT ages using forward thermal and FT annealing calculations, we interpreted the younger ages as being explained by basaltic intrusion. We concluded that the plastic deformation of the biotite grains could have occurred associated with the following events: (1) primal cooling of the granitic body at 68–50 Ma and/or (2) basaltic intrusion at ~19 Ma. A combination of detailed observation of microscale deformation structures and dense FT measurements successfully constrained timing of fault events distributed in bedrock without covering layers.