[S-GL21] Geochronology and Isotope Geology

[SGL21-02] Multi method dating approach to decipher timing of brittle deformation

*Horst Zwingmann¹, Tonguc Uysal², Andrew Todd³ (1.Kyoto University, KUEPS, Japan, 2.The University of Queensland, Brisbane, QLD, Australia, 3.CSIRO Energy, Kensington, WA, Australia)

Keywords:Brittle faults, authigenic illite, geochronolology, Ar-Ar, K-Ar, Rb-Sr, Sm-Nd

Brittle faults are widespread within the shallow crust and contain authigenic clay minerals such as illite, which can be dated by numerous geochronological methods (K-Ar, Ar-Ar, Rb-Sr, Sm-Nd) to constrain timing of deformation. In addition, constraining timing of faulting has been combined with low temperature thermochronological tools comprising AFTA, ZTFA, U-Th/He dating. Many studies focus on single method dating due numerous constraints including time and funding but, most isotope dating methods have advantages and shortcomings. Multimethod studies have been applied within sedimentary environments to date authigenic illite formation mainly in relation to resource exploration (e.g., Awwiller, 1994; Işik, et al., 2014, Middleton et al., 2014; Uysal et al. 2020, Zwingmann et al., 1999). Applying a multi method dating approach will provide improvement of reliability of age constraints of brittle deformation within the shallow crust. Applications of the multimethod dating approach in the constraint of timing of brittle faults will be highlighted within case-studies from Japan, Australia, and Europe.

References
Awwiller, D.N., 1994. Chem. Geol. 116, 61-84.
Işik, et al., 2014, Tectonics, 33, 1875–1899, doi:10.1002/2014TC003565
Middleton et al., 2014. Geochim. Cosmochim. Acta. 134, 155-174.
Uysal et al., 2020. Solid Earth, 11,1653-1679
Zwingmann et a., 1999. Geochim. Cosmochim. Acta, 63, 18, 2805-2823