rocks types

1. Rock Types Sedimentary Metamorphic Igneous

2. Igneous Rock What are Igneous Rocks? Igneous rocks are formed from the solidification of molten rock material. There are two basic types: 1) intrusive igneous rocks  2) extrusive igneous rocks

3. Igneous Rock Formed Igneous rocks are called fire rocks and are formed either underground or above ground. Underground, they are formed when the melted rock, called magma, deep within the earth becomes trapped in small pockets. As these pockets of magma cool slowly underground, the magma becomes igneous rocks. Igneous rocks are also formed when volcanoes erupt, causing the magma to rise above the earth's surface. When magma appears above the earth, it is called lava. Igneous rocks are formed as the lava cools above ground.

4. Igneous Rock Examples Basalt Lava   - Basalt is a hard, black volcanic rock. Less than ½ of the weight of basalt is silica (SiO2 Dacite lava  is most often light gray, but can be dark gray to black.

5. What are Sedimentary Rocks? Sedimentary rocks are formed by the accumulation of sediments. There are three basic types of sedimentary rocks: 1) classic sedimentary rocks 2) chemical sedimentary rocks 3) organic sedimentary rocks Sedimentary Rock

6. Sedimentary Rock Formed For thousands, even millions of years, little pieces of our earth have been eroded--broken down and worn away by wind and water. These little bits of our earth are washed downstream where they settle to the bottom of the rivers, lakes, and oceans. Layer after layer of eroded earth is deposited on top of each. These layers are pressed down more and more through time, until the bottom layers slowly turn into rock.

7. Sedimentary Rock Examples Conglomerate  is made up of rounded pebbles cemented together Breccia  is made up of angular pebbles cemented together.

8. Metamorphic Rock What are Metamorphic Rocks? Metamorphic rocks have been modified by heat, pressure and chemical process usually while buried deep below Earth's surface. There are two basic types of metamorphic rocks: 1) foliated metamorphic rocks  2) non-foliated metamorphic rocks 

9. Metamorphic Rock formed Metamorphic rocks are rocks that have "morphed" into another kind of rock. These rocks were once igneous or sedimentary rocks. How do sedimentary and igneous rocks change? The rocks are under tons and tons of pressure, which fosters heat build up, and this causes them to change. If you exam metamorphic rock samples closely, you'll discover how flattened some of the grains in the rock are.

10. Metamorphic Rock Examples Quartzite  is a coarse-grained metamorphic rock derived from sandstone. Marble  is a metamorphic rock that comes from metamorphosed limestone or dolomite.