13.3. Geological Structures and Mountain Building – Review Questions

• What types of stress are present in the Earth’s crust? What are the sources of these stress? What deformation structures are generated in rocks by these stresses?

• Explain the differences between elastic, ductile, and brittle deformation.

• Where in the Earth’s crust would you expect to find brittle deformation occurring? Why? Where would you expect to find ductile deformation occurring? Why?

• Draw and label simple diagrams to illustrate the three principal stresses that drive deformation.

• Draw and label diagrams to show large scale (e.g., outcrop to regional scale) geologic features that are associate with each type of stress. Think about what small scale (rock sized to microscopic) features would be associated with each type of stress.

• Draw and label structures that result from elastic, ductile, and brittle deformation.

• List the factors that influence deformation in strained rock. Explain how each can vary and what the effect is on rock deformation.

• What are the similarities and differences between the deformation processes that produce faults and folds?

• How do the types of deformation processes that occur change with depth in the lithosphere and rock strength?

• Draw cross-section diagrams of strike-slip, normal, reverse, and thrust faults. Label the strike, dip, and direction of movement for each fault type. In which tectonic environment(s) would you expect to find each type of fault?

• Draw and label cross-sections of folds including symmetrical, asymmetrical and overturned folds. Label the strike, dip, and dip direction for each limb. Label the anticlines, synclines, and other features of the folds. If you want to really challenge yourself: If you cut a cross-section through the folds from a different angles, what would the maps look like (including strike and dip symbols)?

• Describe the three broad types of mountain building processes. How do these processes related to plate tectonic activity? Describe the folding and faulting features associated with each type of process (where applicable).

• Describe the features of fold and thrust belts and give examples of two locations where we see fold and thrust belt mountains on Earth today.

• Google “rock deformation” and look at the image results. Describe a few of the photo results as best you can, using the terms you have learned for describing deformation processes, fold structures, etc.

• Google “fault” and look at the image results. Try to identify the strike, dip, and dip direction for folds and faults in the images (for many of the images you will need to draw or imagine the rocks in 3-D).

Extra review questions that may be covered in lecture (depending on your professor) that are not completely covered in the the textbook readings:

• What are the parts of a geologic map? What kinds of information about rocks do geologists include on a geologic map?