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.