Rocks and Minerals Igneous

Rocks and Minerals Rocks: naturally occurring combination of minerals (minerals are the building blocks for rocks) Minerals: natural, solid substance that has definite chemical composition and physical structure. All rocks contain minerals. The building block of rocks

Igneous rocks

Igneous Rocks “fire rocks” Cooled magma or lava Magma= molten (melted) rock inside earth Lava= molten rock that reaches the surface of earth **heating and cooling of in mantle layer may lead to this formation

Igneous

2 Types of Igneous Rock Intrusive : Igneous rock that forms as magma cools BELOW the Earth’s surface (also called plutonic rock) Example: Granite

Extrusive Rock Igneous rock that forms as lava cools ON Earth’s surface Example: pumice and rhyolite Basalt forms on ocean floor

Igneous rock texture Depends on how fast the magma cool. Intrusive rocks tend to have large crystals Extrusive rocks tend to have smaller crystals

Intrusive Igneous rock formation Rock Ship (New Mexico)

Basalt Columns at Yellowstone National Park

Discussion How do igneous rocks form? Where do intrusive rocks form? Igneous rocks form from the cooling and crystallization of molten rock above or below Earth's surface. Where do intrusive rocks form? They form underground as magma cools. How are extrusive and intrusive igneous rocks different? Extrusive rocks result from cooling and crystallization above ground. Intrusive igneous rocks form deep within Earth.

Challenge Why are there holes in some igneous rocks? Holes in igneous rock form as gases escape from the molten mixture during an eruption.