Physically-based Kinematic Model: from sandbox experiment Nina Lin Ge 277, Nov 7 2008 Readings:...
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Physically-based Kinematic Model: from sandbox experiment Nina Lin Ge 277, Nov 7 2008 Readings: Bernard et al. (2007) Kinematics of fault-related fol ding derived from a sandbox experiment, JGR Daëron et al. (2007) Modeling the shortening history of a fault tip fold using structural and geomorphic r ecords of deformation, JGR
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Transcript of Physically-based Kinematic Model: from sandbox experiment Nina Lin Ge 277, Nov 7 2008 Readings:...
Physically-based Kinematic Model:from sandbox experimentNina LinGe 277, Nov 7 2008
Readings:Bernard et al. (2007) Kinematics of fault-related folding derived from a sandbox experiment, JGRDaëron et al. (2007) Modeling the shortening history of a fault tip fold using structural and geomorphic records of deformation, JGR
Q: How is the geologic deformation related to seismic cycles?
PlanarFaultScenario
Q: How is the geologic deformation related to seismic cycles?
ListricFaultScenario
Q: How do we determine the right kinematics of a fold?
Traditional Kinematic Models: FBF
dZ
x
Traditional Kinematic Models: FTF
→ Need understanding of structural type→ Complicated to derive velocity-deformation relationship
Physically-based Kinematic Model:Analogous Experiment
Phase I: Distributed StrainDetachment-tip Folding
Phase II: Strain LocalizationRamp Overthrusting
Insights of experiment:1. Maximum Uplift
Much higher internal deformation during FTF
Phase I Phase II
Insights of experiment:2. Velocity Field of FTF (Phase I)
)Z(W/X1VV SH
Insights of experiment:3. Comparison with Elastic Model
Fault-Tip Fold:
→ Fault depth is too shallow
→ Slip is overestimated
Phase I
Insights of experiment:3. Comparison with Elastic Model
Fault-Bend Fold:
→ Fault depth is too shallow
→ Slip is overestimated
Phase II
Example I:Yakeng Anticline, S Tien Shan
Example I:Yakeng Anticline, S Tien Shan
Example I:Yakeng Anticline, S Tien Shan
dZx
Example I:Yakeng Anticline, S Tien Shan
Excess Area Finite Shortening Shortening Rate:
0.14 mm/yr for 2.1-5.8 Ma
Example I:Yakeng Anticline, S Tien Shan
Example I:Yakeng Anticline, S Tien Shan
No age control
Age determined by constant sedimentation rate
Shortening rate could be 2.1 mm/yr for 150 ka
Much faster than 0.14 mm/yr for 2.1-5.8 Ma
Implications
Physically-based kinematic model offers an approach to model geologic deformation in terms of seismic cycles
Combining with coseismic deformations, one can determine the inelastic deformation in the medium and possibly folding mechanism
Example II:Anjihai Anticline, N Tien Shan
Example II:Anjihai Anticline, N Tien Shan
Example II:Anjihai Anticline, N Tien Shan
Pretectonic
Example II:Anjihai Anticline, N Tien Shan
Example II:Anjihai Anticline, N Tien Shan
Example II:Anjihai Anticline, N Tien Shan
Mismatch of Tn: Change of tectonic pattern Different age of Ts and Tn
