Rocks

This Presentation is About:

Igneous Rocks

Sedimentary Rocks

Metamorphic Rocks

Igneous RockIgneous rock is formed from molten rock that

hardened into a solid state.

Types of Igneous Rock

• There are two types of igneous rock:

Extrusive, which forms from lava that hardens on Earth’s surface.

Intrusive, which forms from magma that hardens beneath Earth’s surface.

Molten Rock Above Surface (Lava)

Lava Cools Quickly and Hardens into

Extrusive Rock

Extrusive Rock

Molten Rock Below Surface

(Magma)

When the Volcano Stops Erupting, the Magma Cools Slowly and Hardens into Intrusive Rock

Intrusive Rock

Examples

• Intrusive

GranitePorphyryPegmatite

• Extrusive

BasaltObsidianRhyolite

Sedimentary Rock

Sedimentary rock is made of sediment that has been deposited, compacted, and cemented.

Types of Sedimentary Rock

• There are three types of sedimentary rock:

Clastic, which is formed when rock fragments are squeezed together.

Organic, which forms when the remains of plants and animals are deposited in thick layers.

Chemical, which forms when minerals that are dissolved in a solution crystallize.

Clastic Rock

Scattered Rock Fragments

Rock Fragments Squeezed Together

Organic Rock

Soil

Layer of Organic Material Above

Soil

Compacted Organic Material Eventually Hardens into Rock

Organic Material gets Covered with Soil and

Compacts Together

Chemical Rock

Minerals Get Deposited in

Water

Minerals Dissolve in

Water

Minerals Crystallize

Examples

• ClasticShaleSandstoneConglomerateBreccia

• OrganicCoalLimestone

• ChemicalLimestone

Metamorphic Rock

Metamorphic rock is any rock that has gone under immense heat and pressure to

transform into another rock.

Types of Metamorphic Rock

• There are two types of Metamorphic rock:

Foliated, which is when the rock grains are arranged in parallel layers or bands.

Nonfoliated, which is when the rock grains are arranged randomly.

Foliated Rock

Nonfoliated Rock

How Metamorphic Rocks are Formed

Magma

Earth’s Crust

Rock Layers

HEAT AND PRESSURE

Examples

• Foliated

SlateSchistGneiss

• Nonfoliated

Marble Quartzite

Amber Fox Productions

Illustrations: Amber Fox

Animation: Amber Fox

Sound: Amber Fox

Text: Amber Fox

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