Geol 101 - Ch. 4 Up from the Inferno: Magma and Igneous Rocks

studied byStudied by 16 people
5.0(2)
Get a hint
Hint

What is a volcano?

1 / 45

flashcard set

Earn XP

Description and Tags

TEXTBOOOK RAAAAAAAAAAAAAAAH

46 Terms

1

What is a volcano?

A vent or opening from which melt that originates inside the Earth emerges onto the planet’s surfaces.

New cards
2

What is magma?

Underground melt; molten rock beneath the Earth’s surface.

New cards
3

What is lava?

Emerged melt'; molten rock that has flowed out onto Earth’s surface.

New cards
4

What is extrusive igneous rock?

Forms when lava that freezes above ground comes into contact with air/water after it erupts.

<p>Forms when lava that freezes above ground comes into contact with air/water after it erupts. </p>
New cards
5

What is pyroclastic debris?

Fragmented material that sprayed out of a volcano and landed on the ground/seafloor in solid form.

New cards
6

What is volcanic ash?

Tiny glass shards from lava sprays.

New cards
7

What is intrusive igneous rock?

Rock formed by the freezing of magma underground; solidification of magma.

<p>Rock formed by the freezing of magma underground; solidification of magma. </p>
New cards
8

What are causes of melting?

  1. Decompression

  2. Addition of Volatiles

  3. Heat Transfer

New cards
9

What is decompression?

Decrease in pressure triggers melting as long as temperature stays the same.

<p>Decrease in pressure triggers melting as long as temperature stays the same. </p>
New cards
10

What is the addition of volatiles?

Substances that evaporate really easily; decreases a rock’s melting temperature.

New cards
11

What is melting due to heat transfer?

Hot magma from the mantle rises into the crust and it’s heat raises the temperature of surrounding crustal rock.

New cards
12

What do all molten rocks include?

Silica (SiO2)

New cards
13

What are dry melts?

They do not contain volatiles.

New cards
14

What are wet melts?

They contain volatiles.

New cards
15

Mafic Melts

Contain a relatively high proportion of magnesium oxide/iron oxide with silica

New cards
16

Ultramafic Melts

An even higher proportion of magnesium oxide and iron oxide.

New cards
17

Intermediate Melts

Composition between the mafic and felsic melts.

New cards
18

Source-rock Composition

Reflects the composition of the solid from which it was derived.

New cards
19

Partial Melting

Lowest temperature materials melt while higher temperature remain solid.

<p>Lowest temperature materials melt while higher temperature remain solid. </p>
New cards
20

Assimilation

The incorporation of chemicals that dissolved from the wall rock/from blocks that detached from the wall and sank into magma.

<p>The incorporation of chemicals that dissolved from the wall rock/from blocks that detached from the wall and sank into magma. </p>
New cards
21

Magma Mixing

Formed in different locations from different sources that may come into contact underground.

New cards
22

Why does magma rise?

  1. Buoyancy

  2. Magma Pressure

New cards
23

What controls the speed of magma flow?

Viscosity; The resistance of material to flow

New cards
24

Which is more viscous?

A dry melt is more viscous than a wet melt.

New cards
25

What are the three factors the cooling time of magma?

  1. Depth of intrusion

  2. The shape and size of a magma body

  3. The presence of circulating groundwater.

New cards
26

What is fractional crystallization?

The process by which a magma becomes progressively more silicic as it cools, because early-formed crystals settle out.

New cards
27

What is a magma chamber?

A space below ground filled with magma; does not contain melt, rather a “mush”

New cards
28

Extrusive Igneous Settings

When this lava freezes; it forms a thin lava flow which takes days-months to cool.

New cards
29

Intrusive Igneous Settings

Roughly planar and have a fairly uniform thickness; forms when magma injects into cracks underground.

New cards
30

What is a dike?

A tabular intrusion that cuts across pre-existing layering.

New cards
31

What is a sill?

A tabular intrusion that injects between layers; parallel

New cards
32

Laccolith

A blister-shaped igneous intrusion that forms when magma injects between layers underground

New cards
33

Plutons

Blob-shaped intrusions that range in size from tens of meters to tens of kilometers across; form when magma in a magma chamber solidifies.

New cards
34

Batholith

Resulting immense mass of igneous rock

New cards
35

Where do dike intrusions exist?

In regions where the crust stretches horizontally happens in a rift; magma forces it way a vertical crack → walls of crack move apart sideways.

New cards
36

How is the space of plutons developed?

Rose upward though the crust as light-bulb-shaped blobs of magma that pierced overlying rock and pushed it aside as they rose.

New cards
37

Stoping

A process during which magma assimilates wall rock, and blocks of wall rock break off and sink into the magma.

New cards
38

Xenolith

A relict of wall rock surrounded by intrusive rock when the intrusive rock freezes

New cards
39
<p>What texture is this?</p>

What texture is this?

Crystalline Texture

New cards
40
<p>What texture is this?</p>

What texture is this?

Fragmental Texture

New cards
41
<p>What texture is this?</p>

What texture is this?

Glassy Igneous Rocks

New cards
42

What are hot spots?

Igneous activity with mantle plumes rising from deep in the mantle.

New cards
43

Volcanic Arc

Forms on the overriding plate adjacent to the deep-sea trenches that mark convergent boundaries.

New cards
44

How does subduction trigger melting?

Volatiles are bonded to other elements within mineral crystals

New cards
45

Large Igneous Province (LIP)

A region in which huge volumes of lava/ash erupted over a relatively short interval of geologic time.

New cards
46

Flood Basalts

Vast sheets of basalt that spread from a volcanic vent over an extensive surface of land; formed by rifting above a continental hot spot.

New cards

Explore top notes

note Note
studied byStudied by 2 people
Updated ... ago
5.0 Stars(1)
note Note
studied byStudied by 12 people
Updated ... ago
5.0 Stars(1)
note Note
studied byStudied by 14 people
Updated ... ago
5.0 Stars(1)
note Note
studied byStudied by 15 people
Updated ... ago
5.0 Stars(1)
note Note
studied byStudied by 107 people
Updated ... ago
5.0 Stars(1)
note Note
studied byStudied by 3 people
Updated ... ago
5.0 Stars(1)
note Note
studied byStudied by 13 people
Updated ... ago
5.0 Stars(1)
note Note
studied byStudied by 73 people
Updated ... ago
5.0 Stars(1)

Explore top flashcards

flashcards Flashcard27 terms
studied byStudied by 11 people
Updated ... ago
5.0 Stars(1)
flashcards Flashcard24 terms
studied byStudied by 20 people
Updated ... ago
5.0 Stars(1)
flashcards Flashcard97 terms
studied byStudied by 3 people
Updated ... ago
5.0 Stars(1)
flashcards Flashcard45 terms
studied byStudied by 91 people
Updated ... ago
5.0 Stars(1)
flashcards Flashcard70 terms
studied byStudied by 11 people
Updated ... ago
5.0 Stars(1)
flashcards Flashcard95 terms
studied byStudied by 7 people
Updated ... ago
5.0 Stars(1)
flashcards Flashcard23 terms
studied byStudied by 1 person
Updated ... ago
4.0 Stars(1)
flashcards Flashcard33 terms
studied byStudied by 66 people
Updated ... ago
4.0 Stars(4)