Wednesday, April 12, 2023

The Earth’s Crust

Rock FamiliesIgneous Rock

Rock Families

#1 Igneous

There are three rock families:

#2 Sedimentary

#3 Metamorphic

1. Igneous Rock

Igneous Rock - “Born of Fire”

Igneous rock forms from melted rock (lava or magma) when it cools.

Lava – melted rock that is found outside (“on”) the Earth’s crust

Magma – melted rock that is found inside the Earth’s crust

Magma – melted rock that is found inside the Earth’s crust

Lava – melted rock that is foundoutside (“on”) the Earth’s crust

Lava sampling

When lava and magma cool, they form two different kinds of Igneous rock:1. Intrusive rock – igneous rock that is formed from cooled magma (e.g. granite)

2. Extrusive rock – igneous rock that is formed from cooled lava (e.g. pumice)

The main difference between intrusive and extrusive rock is their crystal size, which depends on how quickly they cool.

Intrusive rock (from magma) cools very slowly inside the Earth’s crust

and forms large crystals.

Extrusive rock (from lava) cools quickly and forms small crystals..

Igneous rock video

Examples of Igneous Rock:GranitePumiceObsidianBasalt