Geology Chapter 11

When did Pangea begin to break into smaller fragments?

180 million years ago

If strike and dips symbols were placed on a map of a basin, which way would the dips point?

Dips point down toward the center.

Imagine a fold has been eroded to a flat surface. In general, how would you know whether this fold is plunging?

Non-plunging folds look like straight lines at the surface, and plunging folds look like wavy lines.

_____ faults combine elements of strike-slip and dip-slip motions.

Oblique-slip

Which of the following statements best describes the orientation of rock layers for a structural dome or structural basin?

Rock layers wrap around a single point.

Imaging a syncline has been eroded to a flat surface. How would the rock age change as you walked across that flat surface?

Rocks would be oldest on the edges and youngest in the middle.

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 eyes and oldest in the middle.

What does a turbidite sequence consist of?

a blanket of sand overlain by a sheet of mud

What produces plunging folds?

a combination of folding and tilting

What is a syncline?

a fold shaped like a right-side-up U

What is an anticline?

a fold shaped like an upside-down U

What does the term plunging fold mean?

a fold that is tilted down into Earth

Which type of force causes folding?

compressional force

What are stromatolites?

mats of blue-green algae that grew in mounds up from the sea floor

Which fault will see the hanging wall move down relative to the footwall?

normal fault

Which of the following rocks are characteristics of compressional mountain building?

schist

What causes metamorphism to occur in the Blue Ridge District during the Alleghanian Orogeny?

strong differential stress generated by compressional stress as rocks were thrust westward

What is the geologic term for folded rocks with the bend at the bottom?

syncline

In a normal fault ______.

the hanging wall block above an inclined fault plane moves downward relative to the other block.

Which geologic features would be present in compressional mountain belts?

thrust faults, intrusive igneous rocks, folds

Which of the following scenarios could result in the development of a compressional mountain belt?

two landmasses collide