2.2 - Igneous Rock

Question 1

Felsic Rocks

Answer 1

Light-colored rocks that are rich in elements such as aluminum, potassium, silicon, and sodium.

Question 2

Mafic Rocks

Answer 2

Dark-colored rocks that are rich in elements such as calcium, iron, and magnesium, and are poor in silicon.

Question 3

Intrusive Igneous Rock

Answer 3

Rock that forms when magma intrudes, or pushes into surrounding rock below the Earth’s surface and cools.

Question 4

Plutons

Answer 4

Large, irregular-shaped intrusive bodies.

Question 5

Batholiths

Answer 5

The largest of all igneous intrusions.

Question 6

Stocks

Answer 6

Intrusive bodies that are exposed over smaller areas than batholiths.

Question 7

Dikes

Answer 7

Sheetlike intrusions that cut across previous rock units

Question 8

Sills

Answer 8

Sheetlike intrusions that are oriented parallel to previous rock units.

Question 9

Extrusive Igneous Rock

Answer 9

Igneous rock that forms from magma that erupts, or extrudes, onto the Earth’s surface.

Question 10

Lava Flow

Answer 10

When lava erupts from a volcano.

Question 11

Fissures

Answer 11

Long cracks in the Earth’s crust.

Question 12

Lava Plateau

Answer 12

When lava flows out of fissures onto land, the lava covers a large area and form a plain.