The role of thrust faulting in the formation of the eastern Alaska Range: Thermochronological constraints from the Susitna Glacier Thrust Fault region of the intracontinental strike-slip Denali Fault system

A key insight from this study is the identification of middle Miocene initiation of thrust faulting along the Susitna Glacier Thrust Fault (SGTF), which intersects the Denali Fault system. This finding sheds light on the tectonic evolution of the eastern Alaska Range, revealing episodic cooling and exhumation linked to progressive activation of faults due to varying strain partitioning along the Denali Fault. The research employs thermochronological techniques, including U-Pb zircon dating, 40Ar/39Ar mica and K-feldspar analysis, and apatite fission track and (U-Th)/He dating, to constrain the region's tectonic history. These data indicate that both sides of the SGTF acted as a coherent block during the Eocene and early Oligocene, with contrasting ages suggesting fault initiation around 25–15 Ma. The study also supports long-term geologic correlations between the Susitna Glacier region and the Ruby Batholith/Kluane Terrane, providing insights into the complex interaction of plate tectonics at the southern Alaskan margin.

Riccio, S. J., Fitzgerald, P. G., Benowitz, J. A., & Roeske, S. M. (2014). The role of thrust faulting in the formation of the eastern Alaska Range: Thermochronological constraints from the Susitna Glacier Thrust Fault region of the intracontinental strike-slip Denali Fault system. Tectonics, 33(11), 2195–2217. Portico. https://doi.org/10.1002/2014tc003646