Geology 1010 CH 11
Terms in this set (28)
Which of the following scenarios best describes the deformation that will occur in different parts of the crust?
Brittle deformation is dominant in the shallow crust; ductile deformation is dominant in the deep crust.
Which of the following is an example of how rocks will respond to compressional stress? (Note: there may be more than one correct answer.)
Which tectonic stress will result in a lengthening of the crust?
Which type of stress on rock is uniform in all directions?
Which type of stress produces most crustal deformation?
Which feature is not considered a rock structure?
Which type of stress would you expect to find at a transform boundary?
Shear. Where two plates are sliding horizontally past each other at a transform boundary, you would observe shear stress being exerted on the rocks. Because there is no vertical motion of the plates, the crustal thickness is unchanged.
Which type of stress would you expect to find at a divergent boundary?
Tension. Where two plates are moving away from each other at a divergent boundary, you would observe tensional stress being exerted on the rocks. This would result in relatively thinner crust along the boundary.
Which type of force causes folding?
What is an anticline?
A fold shaped like an upside down U
What is a syncline?
A fold shaped like a right-side-up U
Imagine an anticline has been eroded to a flat surface. How would the rock age change as you walked across that flat surface?
Rocks would be youngest on the edges and oldest in the middle.
Imagine a fold has been eroded to a flat surface. In general, how would you know whether this fold is plunging?
Nonplunging folds look like straight lines at the surface, and plunging folds look like wavy lines.
What is a large, step-like fold in otherwise horizontal strata called?
What is a fault?
fractures along which rocks move
What are rocks below and above a fault called?
the footwall below and the hanging wall above
Which type of force is responsible for normal fault formation?
Which type of force is responsible for reverse fault formation?
Which type of force is responsible for normal strike-slip formation?
Which type of fault has NO vertical motion of rocks associated with it?
Which type of plate boundary is most associated with Earth's major mountain chains?
convergent plate boundaries
Which of the following describes an accretionary wedge?
a chaotic accumulation of sediments and scraps of ocean crust
What term refers to a zone where two crustal fragments are "welded" together?
What is the geologic term for folded rocks with the bend at the bottom?
What are stromatolites?
mats of blue-green algae that grew in mounds up from the sea floor
What does a turbidite sequence consist of?
a blanket of sand overlain by a sheet of mud
When did Pangea begin to break into smaller fragments?
180 million years ago
_____ is the principle that explains why materials uplift to a certain elevation.