IGNEOUS ROCKS

1
IGNEOUS ROCKS
2
IGNEOUS ROCKS

• 1. Igneous Rock - Rock that forms from hardening
  magma or lava

3

• 2 Type of Igneous Rock

4
IGNEOUS ROCKS

• 1. Extrusive Rock (origin) Igneous rock formed
  from lava that erupted onto Earths surface
  (basalt from oceanic crust)

GLOWING BASALT
OBSIDIAN
BASALT
5
IGNEOUS ROCKS

• 2. Intrusive Rock (origin) Igneous rock that
  formed when magma hardened beneath the Earths
  surface (granite from continental crust)

GRANITE and Gabbro
6
IGNEOUS ROCKS

• Texture Depends on the size and shape of the
  mineral crystals intrusive rock has larger
  crystals

7
IGNEOUS ROCKS

• 1. Fine-Grained (texture) From rapid cooling of
  lava (extrusive) has small crystals

RHYOLITE
8
IGNEOUS ROCKS

• 2. Coarse-Grained (texture) From slow cooling
  of magma (intrusive) has large crystals

GRANITE
9
IGNEOUS ROCKS

• 3. Porphyritic (texture) Intrusive rocks they
  have large crystals scattered on a background of
  much smaller crystals forms when intrusive rock
  cools in 2 stages

10
IGNEOUS ROCKS

• Mineral Composition (silica content in magma)
  Rocks with a low silica content form dark (mafic)
  colored rocks (basalt) and make fast lava flows
  Rocks with a high silica content form
  light(felsic) colored rocks (granite) and slow
  lava flows.

HIGH SILICA CONTENT
LOW SILICA CONTENT
11
IGNEOUS ROCKS

• 9. Other Characteristics of Igneous Rocks Hard,
  dense, durable, used for tools and building
  materials

12
Igneous Uses

• Tools and building materials
• Granite building and statues
• Basalt crushed to make gravel
• Pumice cleaning tools