Types of Rock

Igneous Rock

How does it form?

Rock that has formed from the cooling and solidification of magma or lava.

Igneous Rock

Two Kinds of Igneous Rock:• Intrusive: Form from slowly cooling magma

within the Earth’s surface.• Large Crystals• Rough Texture

• Extrusive: Form from quickly cooling lava on the Earth’s surface• Small Crystals• Fine Texture

Igneous Rock

Sedimentary Rock

• Rock formed from the compaction and cementation of sediments or from the precipitation of minerals in a solution.

• Compaction – squeezing together• Cementation – gluing, sticking together

What is sediment?

• Sediments are fragments of rock that have been broken down as a result of weathering (wind, ice, running water, etc.)

Sedimentary Rock

• Sediments are classified according to their size.

Clay Silt Sand Pebble Cobble Boulder

Clastic Sedimentary Rock

• The word clastic comes from Greek work, meaning “broken” • Formed from particles of rock (clay, silt,

sand that have been compacted together.

Clastic Sedimentary Rock

• Shale formed from fine sediments, (i.e., clay or silt).

Clastic Sedimentary Rock

• Sandstone formed from medium-size sediments, (i.e., sand).

Clastic Sedimentary Rock

• Conglomerates formed from large pebble-size sediments.

Nonclastic Sedimentary Rock

• Formed by chemical precipitation or by organic activity• Salt rock formed by evaporation• Limestone formed by chemical precipitation or

organic activity

• Limestone

Nonclastic Sedimentary Rock

Fossils

• Sedimentary rocks are the only type of rocks that may contain fossils, or evidence of past life.

Metamorphic Rock

•Rock formed from a change that has occurred as a result of exposure to intense heat and/or pressure.

Metamorphic Rock

•Two types of metamorphism1. Contact metamorphism2. Regional metamorphism

Contact metamorphism

• Involves existing rocks coming into contact with really intense heat (i.e., lava / magma).

Regional Metamorphism

• Involves existing rocks experiencing extreme pressure as a result of being pushed together by two converging plates.

Regional Metamorphism

Types of Rock Brochure Project

• Your brochure must include the following pages:• Title Page (e.g., Three Types of Rock) with Name• Contents Page (How the rocks form)

• Provide a definition for each type of rock.

• Rock Type #1: Igneous Rock• Rock Type #2: Sedimentary Rock• Rock Type #3: Metamorphic Rock

• Provide a title for each page of the rock type.

• Each page should include information that is specific to that type of rock.

Igneous Rock• Two Kinds of Igneous Rock:• Intrusive: Form from slowly cooling magma within

the Earth’s surface.• Large Crystals• Rough Texture

• Extrusive: Form from quickly cooling lava on the Earth’s surface• Small Crystals• Fine Texture

Sedimentary Rock

•Two Kinds of Sedimentary Rock:• Clastic: Form from particles of rock (e.g., clay,

silt, and sand)• Compacted Sediments

• Nonclastic: Form from chemical precipitation or by organic materials.

Metamorphic Rock

Two Types of Metamorphism:•Contact Metamorphism: Involves

existing rocks coming into contact with really intense heat (i.e., lava / magma). •Regional Metamorphism: Involves

existing rocks experiencing extreme pressure as a result of being pushed together by two converging plates.