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Fault in the lower Austin Chalk (Cretaceous) exposed in a wall of the Lehigh Quarry near McGregor, Texas.

Fault in the lower Austin Chalk (Cretaceous) exposed in a wall of the Lehigh Quarry near McGregor, Texas. Photo by Vince Cronin.

Introductory Structural Geology, Faults


This page is under construction!

Refer to Ben van der Pluijm and Steve Marshak, Processes in Structural Geology and Tectonics (psgt.earth.lsa.umich.edu), chapter 5, pages 109-135.

Terms you should work to understand and use properly

allochthon anastomosing array antithetic fault argille scagliose autochthon
basin inversion blind fault cataclasite conjugate fault array contractional fault
Coulomb wedge decollement detatchment dip-slip fault displacement
emergent fault exhumed fault extensional fault fault fault array
fault bend fault block fault gouge fault inversion fault splay
fault system fault termination fault wall fault zone footwall
graben groove lineation half-graben hanging wall horst
imbricate fan listric fault mesoscopic cohesion mylonite net slip
net-slip vector nonsystematic fault array normal fault oblique-slip fault passive margin
pseudotachylyte relay array reverse fault rift shear striae
shear zone slicken fiber slicken line slickenside slip lineation
strike-slip fault subsidiary fault thrust paradox thrust sheet thrust wedge
tip line transform fault transtension

Some submitted questions related to this chapter

  1. Draw a cross section showing a normal fault and a reverse fault. Label the following: hanging wall, foot wall, and slip direction.
  2. Draw a cross section showing a reverse fault. Label the following: hanging wall, foot wall, and slip direction.
  3. Draw a cross section of extensional faulting and contractional faulting. Describe what they are and how they differ.
  4. What features are associated with subsidiary faulting and how do they relate to a larger fault zone?
  5. What are fault rocks and how are they classified?
  6. How do horsts and grabens form?
  7. Describe how a fault changes with depth.
  8. How do geoscientists predict potential seismic regions?
  9. Why do large thrust sheets exist, when the stress exceeds the failure strength of the rock?
  10. How do you describe the attitude or orientation of a fault?
  11. What is the difference between thrust faults and a duplex?
  12. At depths between _ km and _ km, faulting tends to yield a fault zone composed of cataclasite.
  13. How do faults terminate?
  14. What are the two classes of fault rocks, and what are their distinguishing characteristics?
  15. What do we call subsidiary faults whose dip is opposite to that of the major faults?
  16. Do faults extend infinitely in all directions?
  17. How do faults contribute to the development of oil traps?
  18. What is the difference between a graben and a half graben in regards to the dip direction of the faults that bound each?
  19. Along what type of tectonic boundary do you find strike-slip faults?
  20. The boundary between the slipped and unslipped region at the end of a fault is called the ___?
  21. Faults terminate where they are cut by younger or older structures?
  22. At what angle to the wall do stepped veins initiate?
  23. Can faults extend infinitely?
  24. What is a fault that does not intersect the ground surface?

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