Test 3 Review

Question 1

What are the major layers of the earth?

Answer 1

Crust, mantle, core, Lithosphere and asthenosphere

Question 2

What are methods to examine earths interior?

Answer 2

-Geophysics(seismic waves)
-Remnants (Coring, Ophiolites, Xenoliths)
-Experiments
-Meteorites

Question 3

What is the difference between P and S waves?

Answer 3

-P waves (Compressional)
-S waves (Shear, can travel through liquid)

Question 4

What are gravity corrections?

Answer 4

-Latitude change
-Free air anomaly
-Bouger Anomaly

Question 5

Plate Definition

Answer 5

Unit of lithosphere that moves as a unit

Question 6

What is evidence of seafloor spreading?

Answer 6

-Magnetic striping (mirrored across the ridge)
-Age of crust
-Depth of crust
-sediment thickness
-Hot spots
- island chains

Question 7

What is a geoid?

Answer 7

Surface of equal gravity

Question 8

Divergent

Answer 8

Plates spread apart

Question 9

Convergent

Answer 9

Plates Move towards each other

Question 10

Transform

Answer 10

Plates slide past each other

Question 11

Evidence for subduction

Answer 11

-earthquakes
-Volcanoes
-gravity

Question 12

Sediment types in divergent margins

Answer 12

red beds, evaporates, reef carbonates, deltaic terrigenous sediments

Question 13

Why thick deposits in divergent margins

Answer 13

-subsidence (cooling & sed weight)
-Sediment damming (basin highs, reefs, salt
diapirs)

Question 14

Features in Convergent margins?

Answer 14

trench, wedge, forearc basin, island arc, back arc basin

Question 15

Processes that happen at convergent margins?

Answer 15

under-thrusting and back arc spreading

Question 16

For creating the wilson cycle what are the 3 factors

Answer 16

-Rifting(Rift valleys/lakes)
-Young ocean (ridges)
-Mature Ocean (Ridges/wide cont. margins)

Question 17

What is the driving forces of plates?

Answer 17

-ridge push
-Slab pull
-Suction

Question 18

For the destruction of the wilson cycle what 3 things happen

Answer 18

-Subduction (ridges, trenches, island arcs, volcanoes, mountains)
-Closing (Trenches, Volcanoes)
-Collision (Mountains)

Question 19

What is panthalassa

Answer 19

pre-pacific, single ocean

Question 20

Why over trench zone do you get a plus minus plus

Answer 20

There is more water and sediment

Question 21

Why under island arc do you have a positive body

Answer 21

The plate is over top of the other plate and have a greater gravity value

Question 22

For the rock mountains why is there low value

Answer 22

change in material, there is a root

Question 23

What rock types make up the lithosphere

Answer 23

1. basalts
2. Gabbro(layered at base)
3. Peridotite (layered at top)

Question 24

For hot spots where is the magma source?

Answer 24

Crust mantle boundary

Question 25

For island arc where is the magma source?

Answer 25

Melting overlying plate

Question 26

Tethys sea way

Answer 26

Across the equator to move across the ocean during cretaceous

Question 27

Temp of water was warmer during when

Answer 27

Cretaceous

Question 28

Why do we have less carbonate material from cretaceous to now

Answer 28

Sluggish turn over, more time for respiration and decomposition