1. Physically-based Kinematic Model: from sandbox experiment Nina Lin Ge 277, Nov 7 2008 Readings: Bernard et al. (2007) Kinematics of fault-related folding derived from a sandbox experiment, JGR Daëron et al. (2007) Modeling the shortening history of a fault tip fold using structural and geomorphic records of deformation, JGR

2. Q: How is the geologic deformation related to seismic cycles? Planar Fault Scenario

3. Q: How is the geologic deformation related to seismic cycles? Listric Fault Scenario

4. Q: How do we determine the right kinematics of a fold?

5. Traditional Kinematic Models: FBF dZ x

6. Traditional Kinematic Models: FTF → Need understanding of structural type → Complicated to derive velocity-deformation relationship

7. Physically-based Kinematic Model: Analogous Experiment

8. Phase I: Distributed Strain Detachment-tip Folding

9. Phase II: Strain Localization Ramp Overthrusting

10. Insights of experiment: 1. Maximum Uplift Much higher internal deformation during FTF Phase IPhase II

11. Insights of experiment: 2. Velocity Field of FTF (Phase I)

12. Insights of experiment: 3. Comparison with Elastic Model Fault-Tip Fold: → Fault depth is too shallow → Slip is overestimated Phase I

13. Insights of experiment: 3. Comparison with Elastic Model Fault-Bend Fold: → Fault depth is too shallow → Slip is overestimated Phase II

14. Example I: Yakeng Anticline, S Tien Shan

17. dZ x Example I: Yakeng Anticline, S Tien Shan Excess Area  Finite Shortening  Shortening Rate: 0.14 mm/yr for 2.1-5.8 Ma

18. Example I: Yakeng Anticline, S Tien Shan

19.  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

20. 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

21. Example II: Anjihai Anticline, N Tien Shan

23. Pretectonic

24. Example II: Anjihai Anticline, N Tien Shan

26. Mismatch of Tn:  Change of tectonic pattern  Different age of Ts and Tn