What sorts of geologic structures would an earth scientist expect ...

[cnetterville]

What sorts of geologic structures would an earth scientist expect to find forming in a convergent plate boundary? Draw a cross section to help explain your answer.
 
  What will be an ideal response?

Question 2

How do terranes relate the growth of continental crust over geologic time? What region of North America illustrates this process well?
 
  What will be an ideal response?

[Pamela.irrgang@yahoo.com]

Answer to Question 1

Answer: You would expect structures that form under compression. Reverse (and thrust) faults would be forming at relatively shallow depths, where rocks are deforming in a brittle fashion. Folding of the rocks into anticlines and synclines would also be likely. I'd expect some variation on this diagram:

Answer to Question 2

Answer: Terranes are relatively small crustal fragments (microcontinents, volcanic island arcs, or oceanic plateaus). Terranes may be accreted to continents when subduction brings them to a trench, but they usually do not subduct due to their relatively low density. The terranes are peeled off the subducted slab and thrust onto the leading edge of the continent. Thus, they add bulk (mass, volume) to the edge of the continent. The western Cordillera is composed of many accreted terranes that originated mostly far to the south. Tectonic motions slathered them on to the edge of North America, and so their deformed, metamorphosed bulk piles up on the continent's leading edge like smashed bugs on the windshield of a fast-moving car.

[cnetterville]

TY

[Pamela.irrgang@yahoo.com]

Happy to Help