chapter 4 Igneous rocks

Question 1

what are igneous rocks mostly made of?

Answer 1

partially melted magma and silicate materials

Question 2

this is molten rock, suspended crystals and dissolved gas

under the earth’s surface only

Answer 2

magma

Question 3

the 3 materials of magma

memorization trick:
G
Li quid
S

name them and describe them

Answer 3

G as- volatiles/rock vapors
Li quid called melt
S olid- crystaline mush of silicates

Question 4

this is molten rock on EARTH”S SURFACE ONLY

Answer 4

lava

Question 5

___ reverses the events of melting and forms a solid

Answer 5

what is crystalization

Question 6

describe how magma cools

Answer 6

silicon link together in tetrahedras

Question 7

ignieous ricks with lots of silicates, quartz and feldspar is called___ which mosty solidifies into

Answer 7

felsic

granite

Question 8

igneuous frocks with DARK silicates(Mg, Fe) is called___ which forms into magma having a _____ composition

Answer 8

mafic

basaltic

Question 9

this composition is in between felsic and mafic

25% dark siicates

Answer 9

andesitic composition

Question 10

rank these from high to low silica content

mafic, felsic, bafic

Answer 10

felsic
mafic

Question 11

overall appearance of a rock based on the size, shape, and arrangement of its mineral grains is called ____

Answer 11

texture

Question 12

rapid cooling creates ___ type of texture called

Answer 12

fine grained
aphantic

Question 13

crystalization

Answer 13

1. generation or percipitation of mineral grains
2. as magma cools movements of ions slows

Question 14

steps to name an igneous rock
1. extrusive or intrusice (small or big crystal)
2. chemistry
3. mineralology
4. texture

Question 15

slowly cooling magma at a great depth has a ___ texture called P_____

hint: slow, big back

Answer 15

Coarse texture
phantraphenic

phaner= visable

Question 16

Porphyritic texture is both ___

Answer 16

extrusive and intrusive texture

Question 17

pegrmatitie texture

Answer 17

VERY LARGE course rocks, larger than 1 cm in diameter

Question 18

holes in rocks are called ___ texture

swiss cheese is holy

Answer 18

Vesicular texture

Question 19

(very quickly cooled) and becomes a solid. Rapid cooling of this type may generate rocks iswhat texture?

Answer 19

glassy

Question 20

pyroclastic texture

Answer 20

condensition fo fragments od ash, mo.ten blobs ejected during exploive volcano

Question 21

the most common pyroclastic rock

Answer 21

tuff

Question 22

geothermal gradient (redline)

Answer 22

the gradual inc in temp in earth’s crust

Question 23

what effects the way rocks melt?

Answer 23

pressure, introduction of water,

Question 24

when a rock melts due to a DEC IN PRESSURE it is called

Answer 24

decompression melting

Question 25

when i add water to rock melting what happens? where does this happpen?

Answer 25

rock melts at a lower temperture happens at subduction

Question 26

factional crystaliation

Answer 26

body of magma is injected , darket line at the bottom is ultra mafic

Question 27

assimulation

Answer 27

solid and liquid magma coming up through earths crust, disloges other rocks and melts them thus changes maga body composition

Question 28

magma body mixing

Answer 28

liquid magma a mixing with magma b

Question 29

partial melting

Answer 29

source rock heats up, most idneous melts, but the mafi does not melt

Question 30

columnar joints

Answer 30

rapid coolig of lava, felsic or madic resuktig i hexagonal pillars due to the surface tension and rapid cooling causign shrinkage, hexagons have the least amt of surface evergy

Question 31

layers of rock with lava traveling PARALLELP ALONG THE ROCK is a

Answer 31

sill

Question 32

dike is

Answer 32

orcibly injected into fractures and cut across bedding surfaces and other structures in the host rock SIDEWAYS LAYERS