Standard S6E5.b
Investigate the composition of rocks in terms of minerals

Section 1 pp.90, 95, 96
• Rock • Naturally occurring solid mixture of one or more minerals and organic (living) matter

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• What is the Rock Cycle?
Past uses for Rocks
Used to make…
• The series of processes in which a rock forms, changes from one type to another, is destroyed, and forms again by geological processes.
• Include hammers to make other tools
• Make ancient and modern buildings & monuments

• What is weathering?
• Why is it important?
• What is Erosion?
• What is deposition?
• The process in which water, wind, ice & heat break down rocks
• It breaks down rock into fragments. This is the sediment from which
SEDIMENTARY rocks are made.
• Erosion is the process by which wind, water, ice, or gravity transports soil & sediment from 1 location to another.
• Deposition is the process in which material is laid down.
– Sediments may be pressed
& cemented

• What is uplift?
• What happens when uplift reaches the
Earth’s surface?
• It is movement within the Earth that causes rocks inside the Earth to be moved to the
Earth’s surface
• Weathering, erosion, and deposition begin

• 3 Classes of Rocks 1.
Igneous
2.
Sedimentary
3.
Metamorphic

• Composition
• Texture
• The chemical makeup of the rock –the minerals and other materials
• The size, shape and positions of the rock grains
• Provides clues as to how and where the rock is formed

• Write a paragraph that:
• Compares and contrasts minerals and rocks.

Section 2: pg. 98-101
• Igneous Rocks • Igneous means “fire”
• Begins as magma that contains many minerals
• Cooled magma hardens and solidifies
(becomes a solid)

• Composition of Igneous
Rocks
• Determined by minerals
• Light colored ones – less dense – made of aluminum, siliconFelsic
Rocks
• Dark colored ones – more dense, made of iron, calcium, & magnesium-
Mafic Rocks

• Texture of Igneous Rocks • Size of the grains
• Fast cooling lava on the surface of the volcano -fine grains or no grains Ex: pumice
• Slow cooling magma inside the Earth -large grains
Ex: granite

• Igneous Rock
Formation
• Intrusive igneous rock
– forms inside Earth
– cools slowly
– Many are named for their size & shape
– Large (coarse) grains
• Ex: granite

• Igneous Rock
Formation
• Extrusive Igneous
Rock –
– forms on Earth’s surface
– Common around volcanoes
– cools fast
– fine grains or no grains
Ex: pumice

• Igneous Rock
Formation
• In other words, the faster the magma or lava cools the smaller the grains of the rock
• The slower the magma or lava cools the larger the grains of the rock

• Compare and contrast Stone Mountain’s granite and pumice from a volcano.

• Label intrusive, extrusive, magma, lava.
• Show the grain size of the developing rocks.
• Indicate how fast the rocks cool.
• Name rock samples for each class of igneous rocks.

Section 3 pg. 102 – 105
• Sediments • Fragments of weathered rock & minerals

• Strata • Layers of sedimentary rock on Earth’s surface that forms when the sediment is deposited & cemented together by dissolved clacite & quartz

• Stratification • Process in which sedimentary rocks are arranged in layers
• What do they record?
• Motion of wind & water waves on oceans, rivers, and sand dunes

• Clastic • Made of rock fragments cemented together by dissolved calcite & quartz
• May be any grain size
• Examples: conglomerate, shale, sandstone

• Chemical • From solutions of dissolved minerals in water
• The dissolved minerals crystallize
• Ex: halite —salt—
NaCl Result of supersaturated salt water

• Organic • Made from the remains of dead organisms
• Ex: Chalk is made of tiny sea creatures
• Ex: Coal forms underground when decomposed plant material is changed into coal by heat & pressure
Fossil fuels are nonrenewable resources

• Describe the formation of the 3 classes of sedimentary rock.
• Draw a picture of how each sedimentary rock forms
• Show the rock “before” it became a sedimentary rock and the “after” or the resulting sedimentary rock.
• Label each class of sedimentary rock.

• Compare and Contrast Igneous and
Sedimentary Rocks

Section 4 pg. 106 – 111
• Metamorphism • Change shape
• Metamorphic Rock • The structure, texture or composition of the rock changes because of extreme heat and/or pressure
• A chemical change occurs

• Deformation • Change in the shape of a rock caused by a force, like squeezing or stretching

• Foliated • Mineral grains are arranged in bands
• Ex: mica, slate
• Non-foliated
• Random arrangement of grains
• Commonly made of 1 or a few minerals
• Ex: marble

• If I needed to make a tool from a rock, should I choose a foliated or a non-foliated metamorphic rock? Explain your answer.