Chapter 5: Igneous Rocks

Question 1

What does igneous mean

Answer 1

fire

Question 2

magma vs. lava

Answer 2

under the crust cooling slowly vs on the surface cooling quickly

Question 3

intrusive

Answer 3

coarse-grained igneous rocks that cool slowly beneath Earth’s surface
ex. granite, pegmatite, peridotite

Question 4

extrusive

Answer 4

fined grained igneous rocks that cool quickly on earth’s surface
ex. basalt, rhyolite

Question 5

what is magma made of

Answer 5

slushy, gasses and mineral crystals

Question 6

factors that affect magma formation

Answer 6

temperature, pressure, water content, mineral composition

Question 7

partial melting

Answer 7

the process by which some minerals melt at low temperatures, while others remain solid

Question 8

fractional crystallization

Answer 8

the process wherein different minerals form at different temperatures

Question 9

Bowen’s reaction

Answer 9

relationship between cooling magma and mineral formation

Question 10

Felsic rocks

Answer 10

light coloured rocks that high a high silica content and contain quartz and the feldspar ortho-clase and plagioclase
ex. granite

Question 11

Mafic rocks

Answer 11

dark coloured, lower silica contents and rich in iron and magnesium
ex. gabbro

Question 12

Pegamite

Answer 12

felsic, intrusive

Question 13

Basalt

Answer 13

mafic, extrusive

Question 14

Dunite

Answer 14

ultra mafic, intrusive

Question 15

Obsidian

Answer 15

felsic-intermediate, extrusive

Question 16

Rhyolite

Answer 16

felsic, extrusive

Question 17

Granite Basaltic Glass

Answer 17

mafic, extrusive

Question 18

Periodite

Answer 18

ultra mafic, intrusive

Question 19

porphyritic texture

Answer 19

large, well-formed crystals surrounded by finer grained crystals of the same or different minerals

Question 20

pegmatites

Answer 20

veins of extremely large grained minerals

Question 21

Kimberlites

Answer 21

a variety of periodite, ultra mafic