Rocks, Rocks and More Rocks! Igneous Sedimentary Metamorphic

Igneous Rocks Notes: Extrusive Igneous Rocks Rock formed from lava that erupted onto Earth’s surface. Basalt – most common extrusive rock on Earth. It forms most of Earth’s ocean floor.

Igneous Rocks Earth's Most Abundant Bedrock Basalt underlies more of Earth's surface than any other rock type. Most areas within Earth's ocean basins are underlain by basalt. Although basalt is much less common on continents, lava flows and flood basalts underlie several percent of Earth's land surface. Basalt is a very important rock.

Igneous Rocks Notes: Intrusive Igneous Rocks Rock formed from magma that has hardened beneath Earth’s surface. Granite – the most abundant intrusive rock on Earth’s continents. Forms the core of many mountain ranges.

How igneous rocks form Extrusive Intrusive

Stone Mountain, Georgia Granite is also well-known by its many world-famous natural exposures. These include: Stone Mountain, Georgia

Mount Rushmore, South Dakota

Pike’s Peak, Colorado

Yosemite Valley, California

Igneous Rocks Facts about granite: Granite is the best-known igneous rock. Many people recognize granite because it is the most common igneous rock found at Earth's surface and because granite is used to make many objects that we encounter in daily life. These include counter tops, floor tiles, paving stone, curbing, stair treads, building veneer and cemetery monuments. Granite is used all around us - especially if you live in a city. Facts about granite:

Igneous Rocks Granite

Igneous Rocks Notes for Texture: Fine grained Lava cooling quickly forms a fine-grained rock with small crystals. Example: Basalt - glassy texture, crystals too small to be seen without a microscope. Example: Obsidian –smooth, shiny texture like thick glass & cooled without forming crystals.

Igneous Rocks Obsidian Obsidian on the side of a volcano

Igneous Rocks Notes for Texture: Coarse-grained Slowly cooling magma forms coarse-grained with large crystals Example: Granite

Mineral Composition Notes: When rocks are high in silica they form light-colored rocks like Granite.

When rocks are low in silica they form dark-colored rocks like basalt.

Uses of Igneous Rock Notes: All made from Granite Statues Bridges Buildings Paving streets Curbstones Floors Countertops

Uses of Igneous Rock Gravel for construction – Basalt Cleaning and polishing – Pumice Sharp tools for cutting – Obsidian Fertilizer – Perlite, which is formed from heating Obsidian

Uses of Igneous Rock Statues, Public Buildings - Granite

Uses of Igneous Rocks Cobblestone streets, kitchen countertops