Rock Cycle Vocabulary

Compaction and Cementation

As the layers of sediment build up, the pressure on the lower layers increases. The layers are squeezed together and any water mixed in with the sediments is forced out. This process is called compaction.

The particles of sediment begin to stick to each other - they are cemented together by clay, or by minerals like silica or calcite.

After compaction and cementation the sedimentary sequence has changed into a sedimentary rock. Sedimentary rocks like sandstone, shale and limestone differ from other rocks in that they:

1. Are formed from layers of sediment built up over many years.

2. Are grains of sediment cemented together by various minerals.

3. May contain fossils - remains of plants and animals that were caught up in the sediment.

Sediment

Small, solid pieces of material from rocks or organisms; earth materials deposited by erosion.

Magma

The molten mixture of rock-forming substances, gases, and water from the mantle.

Lava

Liquid magma that reaches the surface, also, the rock formed when liquid lava hardens.

Rock Cycle

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Rock Cycle Vocabulary

Processes undergone by rocks in the earth's crust, involving igneous intrusion, uplift, erosion, transportation, deposition as sedimentary rock, metamorphism, remelting, and further igneous intrusion.

Weathering

• The breaking down of Earth’s materials by natural processes (water, wind, ice, chemicals, etc.) into smaller pieces or sediments.

Erosion

• Weathered rock and soil particles are moved from place to place by water, wind, or ice.

Deposition

• Weathered sediments are laid down in a new location helping create new landforms or rocks.

Melting

• Caused by heat and pressure around the rock to form magma.

Crystallization

• Through heat and pressure, the rock’s atoms and crystals are rearranged.

Igneous Rock

• Formed from the cooling and solidification of magma or lava.

• 2 Types – Extrusive Igneous Rock – Intrusive Igneous Rock.

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Rock Cycle Vocabulary

Extrusive Igneous Rock

• Formed above ground from lava cooling and hardening.

• Characteristics from Cooling Quickly – Small or no crystals. – Fine-grained texture

Intrusive Igneous Rock

• Formed below ground from magma cooling and hardening.

• Characteristics from Cooling Slowly – Large or small crystals. – Coarse-grained texture

Sedimentary Rock

• Formed from sediments (rock fragments, mineral grains, animal or plant remains) that are pressed or cemented together.

Law of Superposition

• States that layers and fossils on top are younger than lower layers.

• Strata – horizontal layers formed from deposited sedimentary rock.

• Stratification – process of arranging sedimentary rocks into layers.

Metamorphic Rock

• Rock changes due to intense heat and high pressure then recrystallizes.

– Not heated enough to melt the rock.

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