Chapter 2 Rocks. Section 1 Lesson Objectives Define rock Describe how rocks change List rock...

Chapter 2 Rocks

Section 1

Lesson Objectives

Define rock Describe how rocks change

List rock characteristics

that help to identify it

Keywords

RockRock cycleIgneousSedimentary Metamorphic

Define rockDescribe how rocks

change List rock characteristics that help to identify it

Keywords: rock, rock cycle

Rock• Naturally occurring solid mixture made of minerals

and organic matter



Keywords: igneous, sedimentary, metamorphic



Rock type is determined by how it is formed

Three types of Rock• Igneous- formed from magma• Sedimentary- formed as a by-product of weathering,

erosion, decomposition• Metamorphic- formed from changes in temperature

and/or pressure


change

Keywords: Rock cycle

List rock characteristics that help to identify it

Rock Cycle• The continual process by which new rock forms from old rock• Rock cycle animation http://www.classzone.com/books/earth_science/terc/content/investigations/es0602/es0602page02.cfm

http://www.classzone.com/books/earth_science/terc/content/investigations/es0602/es0602page02.cfm



Igneous:• Intrusive igneous rocks-

– large crystals cemented together. – Crystallize below Earth's surface – Slow cooling that occurs there allows large crystals to form.

• Extrusive igneous rocks– small crystals some are not visible– Smooth surface– May have air pockets– May look like glass– erupt onto the surface where they cool quickly


change

Keywords: igneous


Ways to tell which rocks are which:

Sedimentary:• Clastic sedimentary rocks

– Fragments of rocks cemented together– Can be course grained like “conglomerate” or fine grained like shale

• Chemical– Liquid evaporates leaving cemented crystals behind

• Organic – May contain fossils


change

Keywords: sedimentary



Metamorphic:• Foliated-

– Banded– crystals seem to go in the same direction

• Non-foliated-– No bands– Can have a glittery appearance


change

Keywords: metamorphic



Type of Rock?

Igneous(Intrusive) Notice the air bubbles

Type of Rock?

Igneous(Extrusive) Notice the absence of visible crystals

Type of Rock?

MetamorphicNotice the bands

Type of Rock?

SedimentaryNotice the pebble-like crystals

Type of Rock?

SedimentaryNotice the sand-like texture

Type of Rock?

IgneousNotice the air bubbles

Type of Rock?

IgneousNotice the separate crystals

Type of Rock?

MetamorphicNotice the

Type of Rock?

SedimentaryNotice the glass-like appearance

Type of Rock?

MetamorphicNotice the glittery appearance

Section 2

Lesson Objectives

Describe three ways that

igneous rocks form

Explain how cooling speed affects texture

Distinguish between

intrusive and extrusive

Describe three ways that igneous rocks form


Keywords

Distinguish between intrusive and extrusive

TextureCompositionIgneous ExtrusiveIntrusive



Keywords: texture, composition


Texture and composition give clues as to how rocks are formed, and are used to classify rocks

• Composition – the type of material a rock contains• Texture – the size, shape and arrangement of the

minerals/particles that make up a rock.• Cooling rate affects texture:

• Rocks that cool faster have very small crystals, air pockets, and can be glassy

• Rocks that cool slower have larger crystals



Keywords


Igneous Rocks- 2 types depending on how formed

Extrusive rocks- formed by cooling lava so cools quickly

Texture:• glassy (obsidian)• porous (pumice)• fine-grained (basalt)

Intrusive rocks- formed by coolingmagma so cools slowly

Texture: • coarse-grained (granite)

obsidian

granite

basalt

pumice

Formation of Extrusive Igneous Rocks

Formation of Intrusive Igneous Rock

Section 3

Lesson Objectives

Describe the 5 agents of erosion

Describe, deposition, compaction

and cementation

Differentiate between types of sedimentary rocks and how

they form


Describe, deposition, compaction and

cementation

Keywords

Differentiate between types of sedimentary rocks and how they

form

ErosionDepositionCompactionCementationWindGravityRunning waterGlaciersWavesSedimentary ClasticChemicalOrganic



cementation

Keywords: sedimentary


form

Sedimentary Rocks• Formed from the erosion, deposition, compaction

and cementation of minerals and other materials• Occurs at or near the earth’s surface• Three types:

• Clastic• Chemical• Organic



cementation

Keywords: clastic, chemical, organic


form

• Clastic Rocks (rock fragments) • Conglomerates (pebbles) • Sandstones (sand) • Shales (mud & clay)

• Chemical Rocks (evaporation)• Ex: rock salt, limestone, geodes, gypsum

• Organic Rocks (once living) • Ex: limestone(coral and shells), coal (plants)

Clastic Sedimentary Rock…made from fragments of rocks cemented

together

Conglomerate

Shale

Sandstone

Chemical Sedimentary Rocks…formed from dissolved minerals that have

crystallized out of solution

Limestone

Gypsum rock

Geode

Organic Sedimentary Rocks…made from previously living organisms

Coal (plant mateiral) Limestone (shell & coral)



cementation

Keywords


form

Five Agents of Erosion

• Gravity (Mass wasting)• Wind• Running water• Glaciers• Waves

Gravity (Mass Wasting)

Slumping

Soil creep

Keywords: gravity



cementation


form



cementation

Keywords: wind


form

Wind



cementation

Keywords: running water


form

Niagara Falls

Yellowstone Canyon & River



cementation

Keywords: glaciers


form

Glaciers



cementation

Keywords: waves


form

Waves



cementation

Keywords: deposition


form

Lateral moraine:

parallel ridges of debris deposited along the sides of a glacier

Nile River Delta:

landform that forms at the mouth of a river, where the river flows into an ocean, sea, estuary, or lake

Deposition Examples



cementation

Keywords: compaction, cementation


form

Compaction and Cementation

Section 4

Lesson Objectives

Describe how metamorphic

rocks are formed

Differentiate between

foliated and non-foliated

rocks

Determine whether rocks will become

either foliated or non-foliated

Describe how metamorphic rocks are

formed

Differentiate between foliated and non-

foliated rocks

Keywords:

Determine whether rocks will become either foliated or non-foliated

MetamorphicFoliatedNon-foliated


formed


foliated rocks

Keywords: metamorphic


Metamorphic Rocks • Formed by tremendous heat &

pressure, and chemical reactions inside the crust.

• Formed from all three rock types.


formed


foliated rocks

Keywords: foliated

Give examples of some metamorphic rocks

Foliated texture


formed


foliated rocks

Keywords: foliated


form

Types of Metamorphic Rock

• Foliated (bands or layers) Ex: schist, slate, gneiss

Gneiss

Slate

http://upload.wikimedia.org/wikipedia/commons/5/5d/St_Fagans_Tannery_7.jpg


formed


foliated rocks

Keywords: non-foliated


Types of Metamorphic Rock continued

• Non-Foliated (no bands or layers) Ex: marble and quartzite


formed


foliated rocks

Keywords: non-foliated


Pressure determines if metamorphic rocks will be foliated or non-foliated• If there is unequal pressure, rocks will be

foliated• If there is equal pressure, rocks will be non-

foliated

Closure:

1. In igneous rocks how is cooling rate and crystal size related?

2. Which rock type would you have the best chance of finding a fossil? Why?

Chapter 2 Rocks. Section 1 Lesson Objectives Define rock Describe how rocks change List rock...

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