Igneous Rocks

Question 1

Igneous rock

Answer 1

Any rock that has formed from a molten material

Question 2

Euhedral Crystal

Answer 2

Good crystal faces

Question 3

Equant crystals

Answer 3

Crystals have all axis the same length

Question 4

Sub-equant crystals

Answer 4

Crystals where all axis are almost the same length

Question 5

Prismatic crystals

Answer 5

Crystals have 4 or more sides then same length elongated in 1 direction

Question 6

Anhedral crystals

Answer 6

Poorly formed crystal faces

Question 7

Sub-hedral crystals

Answer 7

Some well formed crystal faces and some poorly formed faces

Question 8

Igneous texture

Answer 8

The overall view of crystal size and shape

Question 9

Equicrystaline texture

Answer 9

Equal size crystals

Question 10

Vesicular texture

Answer 10

Bubbles trapped in lava

Question 11

Amygdaloidal texture

Answer 11

Infilled vesicles

Question 12

Flow banding

Answer 12

Layers of dark and light minerals aligned due to separation in the lava flow

Question 13

Porphyritic texture

Answer 13

2 distinct crystal faces

Question 14

Ophilitic texture

Answer 14

Elongated crystal enclosed in another crystal

Question 15

Cumulative texture

Answer 15

Crystals which have settled out of magma

Question 16

Magma

Answer 16

Molten rock underground

Question 17

Lava

Answer 17

Molten rock above ground

Question 18

The melting point of silicic material

Answer 18

800°c

Question 19

Enclave

Answer 19

Boobs of magma surrounded by magma of a different comp

Question 20

Exsolition

Answer 20

Brought out of solution

Question 21

Intrusive igneous rock

Answer 21

These crystallise below the surface to form structures called intrusions

Question 22

Concordant intrusion

Answer 22

Intrudes along bedding planes

Question 23

Discordant intrusion

Answer 23

Cuts across bedding planes

Question 24

Country rock

Answer 24

Rocks that magma intrudes

Question 25

Sill

Answer 25

Sheet like concordant intrusions

Question 26

Dyke

Answer 26

Sheet like discordant intrusions

Question 27

Ring complex

Answer 27

Dykes that form ring like structures

Question 28

Come sheets

Answer 28

Pressure from magma forcing upwards fractures that fill with magma

Question 29

Ring dyke

Answer 29

Magma forced along faults

Question 30

Volcanic plug

Answer 30

Magma crystallising in the volcano vent

Question 31

Chilled margin

Answer 31

When he edge of the igneous intrusion next to the country rock rapidly cools allowing small crystals to form

Question 32

Baked margin

Answer 32

The area of the country rock adjacent to a minor intrusion that gets altered by the heat from the intrusion