Discovery Education Rock Cycle

Gravity

A force that exists between any two objects that have mass.

Limestone

A kind of sedimentary rock-some kinds of limestone are made from ancient sea shells.

Exfoliation

A mechanical weathering process in which thin layers of rock on the outer surfaces of outcrops or other rock features break off, often creating dome-shaped patterns.

Rock Cycle

A model describing the transformations of rocks from one major rock type to another. Heat, pressure, cooling, weathering, erosion and deposition change rock. Sun, gravity, and Earth's interior supplies the energy to move materials through this continuous cycle.

Mineral

A natural, solid substance found in rocks; each mineral has a specific chemical makeup.

Cycle

A process that repeats.

Sediment

A solid material, moved by wind and water, that settles on the surface of land or the bottom of a body of water. Forms by weathering, erosion, and deposition. Rocks broken into small pieces of sand and gravel are known as this.

Sedimentary Rock

A type of rock formed by gravity pressing fragments of other rocks and minerals together as they settle on land or under the ocean over a long period of time. Compression and cementation are part of this type of rock formation. Sandstone is an example of this type of rock.

Igneous Rock

A type of rock that forms when melted rock cools and hardens. More specifically, magma and lava cools and hardens.

Chemical Weathering

Changes to rocks and minerals on Earth's surface that are caused by chemical reactions.

Pressure

Force exerted per unit area by many particles or a gas randomly striking the walls of its container.

Earth Materials

General term that includes rocks, minerals, sand, and soil.

Metamorphic Rock

Is produced when rock material is subjected to heat and pressure.

Magma

Melted rock located beneath Earth's surface.

Lava

Melted rock on Earth's surface.

Compression

Occurs when rocks are squeezed by external forces directed toward one another to put stress on the rock, acting to decrease its volume or shorten its dimensions.

Crust

The layer of rock that forms Earth's surface.

Mantle

The layer of solid rock between Earth's crust and core.

Weathering

The physical or chemical breakdown of rocks and minerals into smaller pieces or aqueous solutions on Earth's surface.

Erosion

The process by which wind, water, ice, gravity, or tother natural forces move sediment over Earth's surface.

Melt

To change a substance from solid to liquid.

Granite

A coarse-grained, intrusive, felsic igneous rock composed primarily of quartz, mica, and feldspar. This is an example of an igneous rock.