Geology 001B                                                                                                                       West Valley College

Historical Geology                                                                                                 R. Lopez


Study Questions 10: Continental Tectonics, Chapter 9


1)       What does orogeny mean and what is an orogen?

2)       How do three armed rifts form and what are grabens?

3)       How do three armed rifts relate to the break-up of Pangea.  Name one  famous failed rift in North America.  Is there any seismicity related to failed rifts?

4)       Name some geologic evidence for rifting. For example, is rifting accompanied by volcanism, or are there poorly sorted sediments, or are there lake sediments, or evaporates, or all of these?

5)       There is one and only one way to form Trailing Continental Margins (passive). What is it?

6)       For plunging folds, what is the orientation of the hinge lines (p. 207-208)?

7)       What are the three types of mountain building tectonic possibilities (orogeny)?

8)       Know figure 9-14, p. 211 in text. I will have this figure on the exam.

9)       What are Ophiolites (p. 208)?

10)    What do Ophiolites represent?

11)    Sketch the general stratigraphy of an ophiolite.  Label where the Moho occurs, the crust, and mantle.

12)    What is the fold and thrust belt of mountain belts (read p. 209-210, see Fig. 9-13)?

13)    High standing mountains are gravitationally unstable.  How are they eroded down? (two ways discussed in lecture)

14)    Describe the flattening and bobbing model (crustal rebound).

15)    Describe the delamination model.

16)    What is flysch (read p. 210-211)? Know about the foreland basin (also called the back-arc basin).

17)    Is sandstone or shale typical of flysch deposits?

18)    What is molasses (read p. 210-212)? The Catskill Mountains of New York State are a thick sequence of molasses (clastic wedge).

19)    Understand that flysch and molasses represents evolutionary stages of mountain belt development. The flysch is the early stage whereas the molasses marks a more advance mountain building stage.