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  • Constraining Displacement Magnitude on Crustal‐Scale Extensional Faults Using Thermochronology Combined With Flexural‐Kinematic and Thermal‐Kinematic Modeling: An Example From the Teton Fault, Wyoming, USA
Title: Constraining Displacement Magnitude on Crustal‐Scale Extensional Faults Using Thermochronology Combined With Flexural‐Kinematic and Thermal‐Kinematic Modeling: An Example From the Teton Fault, Wyoming, USA
Abstract Constraining the geometry and displacement of crustal‐scale normal faults has historically been challenging, owing to difficulties with geophysical imaging and inability to identify precise cut‐offs at depth. Using a modified workflow previously applied to contractional systems, flexural‐kinematic (Move) and thermal‐kinematic (Pecube) models are integrated with apatite (U‐Th)/He (AHe) and apatite fission track (AFT) data from Teton footwall transects to constrain total Teton fault displacement (Dmax). Models with slip onset at ∼10 Ma and flexure parameters that best match the observed Teton flexural profile requireDmax > 8 km to produce young (<10 Ma) AHe ages observed at low elevation footwall positions in the Tetons. For the same slip onset, models withDmaxof 11–13 km provide the best match to observed AHe data, but displacements ≥16 km are required to produce observed AFT ages (13.6–12.0 Ma) at low elevations. A more complex model with slow slip onset at ∼25 Ma followed by faster slip at ∼10 Ma yields a good match between modeled and observed AHe ages at aDmaxof 13–15 km. However, this model predicts low elevation AFT ages 6–8 Ma older than observed ages, even atDmaxvalues of 16–17 km. Based on this analysis and integration with previous studies, we propose a unified evolution wherein the Teton fault likely experienced 11–13 km of Miocene‐recent displacement, with AFT data likely indicating a pre‐to early Miocene cooling history. Importantly, this study highlights the utility of using integrated flexural‐ and thermal‐kinematic models to resolve displacement histories in extensional systems.  more » « less
Award ID(s):
1932808
PAR ID:
10522269
Author(s) / Creator(s):
; ; ; ; ;
Publisher / Repository:
AGU
Date Published:
Journal Name:
Tectonics
Volume:
43
Issue:
7
ISSN:
0278-7407
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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