My Notes: Volcanism, Plate Tectonics, and Igneous and Sedimentary Rocks

Question 1

Are all hotspots active right now?

Answer 1

no they come and go

Question 2

Hawaii, Iceland, and Yellowstone are all what types of volcanoes?

Answer 2

Hot Spot volcanoes

Question 3

What are the two types of hot spot volcanoes?

Answer 3

1) extra large plumes along divergent plate boundaries (Iceland)
2) Within plate volcanoes
- small plumes rise under a plate
- Intra-plate hot spots

Question 4

What are intra-plate hot spots?

Answer 4

Occur inside individual plate (Hawaii and Yellowstone)

Question 5

Do hot spots interfere with plate movement?

Answer 5

No, hotspots don’t interfere with individual plate movement

Question 6

True or False: hot spots can occur in continental or oceanic lithosphere.

Answer 6

true

Question 7

Are magma chambers that exists at depths relatively simple or are they complex?

Answer 7

complex

Question 8

When do guyots form?

Answer 8

When volcano is at position that it is almost submerged, wave rods it and we get sea mounts called guyot.

Question 9

Hawaii:
Midway volcanic rocks - ___Ma
Upwards- ___Ma
Downwards - ___Ma

Answer 9

• 40
• 65
• 5-0

Question 10

What is magma contamination?

Answer 10

Rocks (all Precambrian) melt around magma and change its chemistry

Question 11

What do precambrian rocks melt at?

Answer 11

7000 degrees C

Question 12

What are the two types of volcanism that occurs in Northwestern U.S.?

Answer 12

• fissure eruptions (craters coming up under a continent–lava seems to be coming up and puddling at lower part of crust)
• subduction-related volcanoes

Question 13

What happens when lava puddles under the crust, including melting temperatures?

Answer 13

When it puddles, lava is 1000-12000 degrees C. Rocks (all Precambrian) melt at 700 degrees C so they melt around magma and change its chemistry to felsic.

Question 14

Aside rain___in gases.

Answer 14

SO2

Question 15

How does volcanism cause aside rain?

Answer 15

As their gas particles get tied in the atmosphere.

Question 16

Tsunamis: ___km near short

___km/hr

Answer 16

• 50-200

- 800

Question 17

Where do most tsunamis occur?

Answer 17

in Pacific

Question 18

What are the two types of intrusive rock bodies (broad)?

Answer 18

1) Hypabyssal

2) Plutonic

Question 19

What are hypabyssal intrusive rock bodies?

Answer 19

• subvolcanoes (dikes, sills, laccoliths)
• small bodies
• shallow injection
• injected at depths less than 5-10 km

Question 20

What are plutonic intrusive rock bodies?

Answer 20

• several km depth –> considerable depth
• large bodies
• many throw off dikes and may have fed volcanoes
• several km wide

Question 21

What are the three types of relative orogenic age for intrusive bodies?

Answer 21

• Pre-orgenic rock
• syn-orogenic rock
• post-orogenic rock

Question 22

What is the relative age of batholiths?

Answer 22

Batholiths are almost all stn-orogenic – every young and old orogenic belt has them.

Question 23

What is the composition of batholiths?

Answer 23

Almost completely felsic

Question 24

What are talus/scree?

Answer 24

Rock bodies that have fallen - slide from gravity, running water and rain .

Question 25

What does every bed in rock strata represent?

Answer 25

• a geological deposition event
• if conditions remain the same, beds will mostly look the same.
• size of grains deposited change as conditions change
• events can last for seconds-centuries

Question 26

What do rocks represent?

Answer 26

Rocks represent events