Igneous Rocks

Question 1

this texture forms as a result of rapid cooling and has no crystals

Answer 1

hyaline

Question 2

rapid cooling forms microscopic crystals

Answer 2

aphantic

Question 3

slow cooling forms visible crystals

Answer 3

phaneritic

Question 4

very slow cooling very large crystals

Answer 4

pegmatitic

Question 5

complex cooling history multiple crystal sizes

Answer 5

porphyritic

Question 6

molten rock on the surface

Answer 6

Lava

Question 7

molten rock underground

Answer 7

Magma

Question 8

the 3 controls on igneous rock textures

Answer 8

rate of cooling, volatile content, volcanic activity

Question 9

the 2 controls of compositition

Answer 9

quantity of iron and magnesium vs the quantity of silicon and oxygen

Question 10

volatile dissolved gases create this texture when the gas leaves the cooling rock and leaves bubbles

Answer 10

vesicular

Question 11

caused by volcanic activity in during the creation of the rock

Answer 11

pyroclastic

Question 12

high Si + O content, colored white/pastels

Answer 12

Felsic

Question 13

moderate SI + O and moderate Fe + Mg, colored a medium gray

Answer 13

Intermediate

Question 14

high Fe + Mg, colored dark gray to black

Answer 14

Mafic

Question 15

very high Fe + Mg, colored olive green

Answer 15

Ultramafic

Question 16

Inclusion of country rock within an igneous/plutonic rock

Answer 16

Xenolith

Question 17

Felsic, Phaneritic

Answer 17

Granite

Question 18

Felsic, Aphanitic

Answer 18

Rhyolite

Question 19

Intermediate, Phaneritic

Answer 19

Diorite

Question 20

Intermediate, Aphanatic

Answer 20

Andesite

Question 21

Mafic, Phaneritic

Answer 21

Gabbro

Question 22

Mafic, Aphanatic

Answer 22

Basalt

Question 23

Ultramafic, Phaneritic

Answer 23

Peridotite

Question 24

Ultramafic, Aphanatic

Answer 24

Komatite

Question 25

Hyaline

Answer 25

Obsidian

Question 26

Vesicular (<50% vesicles)

Answer 26

Vesicular Basalt

Question 27

Vesicular (>50% vesicles)

Answer 27

Scoria

Question 28

Pyroclastic (Hardened Ashe)

Answer 28

Tuff

Question 29

Pyroclastic (ashe and broken pieces of the volcano)

Answer 29

Volcanic Breccia

Question 30

add this as a suffix, describes larger crystals in a finer groundmass

Answer 30

prophyry

Question 31

add this as a suffix, describes exceptionally large crystals.

Answer 31

pegmatite

Question 32

igneous rock that cooled and solidified at depth

Answer 32

Plutonic rock

Question 33

massive plutons

Answer 33

Batholith

Question 34

mushroom shaped plutons

Answer 34

laccoliths

Question 35

tabular, concordant pluton

Answer 35

sill

Question 36

tabular, discordant pluton

Answer 36

dike

Question 37

The existing stone before the introduction of magma or lava

Answer 37

country rock

Question 38

any change to the composition of magma

Answer 38

magmatic differentiation

Question 39

olivine, pyroxene, amphibole, biotite

Answer 39

discontinuous series

Question 40

Ca-rich to Na-rich plagioclase feldspar

Answer 40

continuous series