Rocks are everywhere. They have been on the earth for over four billion years.  The rock you pick up from the ground might have once been part of a mountain or cave. It might have been around when dinosaurs roamed the earth.
    There are three kinds of rocks. The way they are formed determines the kind of rock that they are. Click on each kind to learn more information.
    • Igneous rocks are the oldest kind of rock.
    • Igneous rocks are formed deep inside the earth where the temperature is very high.
    • The minerals in the earth are in liquid form and are called magma.
    • Magma is squeezed around inside the earth and as it pushes towards the surface of the earth, it starts to cool. As it cools, it turns to solid igneous rock.
    • Sometimes the magma cools very slowly and forms rocks.
    • Igneous rocks that cool slowly deep in the earth are called Intrusive igneous rocks and have large crystals. (Granite)
    • Sometimes the magma erupts from a volcano. Magma is called lava when it reaches the earth's surface. Lava cools quickly and forms igneous rocks.
    • Igneous rocks that cool quickly on the surface of the earth form rocks with small crystals called extrusive rocks. (Basalt, obsidian) 
    • Sometimes extrusive igneous rocks look like glass and have no crystals or mineral particles.
    • Sedimentary rocks are  made from sediments.
    • Sediments are small pieces of other rocks. They turn into pebbles, gravel, sand and clay.
    • Rocks are always being broken into smaller pieces called sediments and worn away (eroded) by wind and water.
    • These little pieces flow along in rivers and streams or blow over the land with the wind and settle in a new place.
    • As they settle, they pile up and form layers.
    • After long periods of time, the pieces become pressed together and form solid rock called sedimentary rock.
    • Sedimentary rocks are usually formed in water.
    • Sedimentary rocks are found all over the world.
    • Many fossils are found in sedimentary rock.
    • Metamorphic rocks are rocks that have changed from one form to another.
    • These rocks form deep in the earth where the it is very hot and there is a lot of pressure.
    • If a rock is heated and squeezed for millions of years, it can turn into a new kind of  rock.
    • Metamorphic rocks begin to form at 12-16 kilometers (7.5 - 10 miles) beneath the surface of the earth.
    • The heat in the earth comes from Magma and the pressure comes from layers of rock piled onto layers of rock.
    •  The layers on the bottom get squeezed and the thicker the layers the more pressure or the more they get squeezed.
    4th Grade Science Curriculum Units
    food web
    1st Marking Period
    2nd Marking Period
    3rd Marking Period
    4th Marking Period
    Earth's Crust
    Electricity, Magnetism & Energy
    Life Science - Characteristics of
    Chemistry and Physics
    Rocks  Minerals  Soil   Fossils
    Rivers  Lakes  Glaciers
    Erosion  Weathering  Landslides
    Volcanic Eruptions   Earthquakes
    Magnetism  Static Electricity
    Devices that show electricity producing heat, light, sound and magnetic effects
    Transfer of heat
    Natural and renewable resources
    Food Chain
    Animal Needs
    Animal Structure and Function
    Classify Organisms
    Life Stage
    Health Related Topics / Body Systems
    Digestive Circulatory Respiratory
    Use magnification to sort materials
    Physical Changes
    Chemical Changes
    Property of Materials

    Follow the link below to learn about different landform types



    All about Topography Maps - A Powerpoint Presentation


    How Rocks are Formed

    Sedimentary Rock

    Water moves bits and pieces of rock, which sink and settle. As they pile up, they're pressed into rock

    Igneous Rock

    The heat of the earth melts rock into a liquid that hardens into different rocks when it cools.


    Metamorphic Rock

    Heat and pressure change sedimentary and igneous rocks into new rock.



    Forms from pressed and cemented layers of shell


    Forms when gas-filled melted rock cools quickly



    Forms when limestone is put under great pressure



    Forms from pressed and cemented layers of mud



    Forms when melted rock cools quickly in air or water



    Forms when shale is put under great pressure



    Forms from pressed and cemented layers of sand



    Forms when melted rock cools slowly underground



    Forms when sandstone is put under great pressure

    Rock Cycle