Ch 3 earth science PPT

igneous rockA rock formed by the crystallization of molten magma... The Rock Cycle Interactions among the Earth’s water, air, and land can cause rocks to change from one type to ano

The Rock Cycle

Ag Earth Science – Chapter 3.1

3.1 VOCABULARY

A consolidated

mixture of minerals

igneous rock

A rock formed by the

crystallization of

molten magma

metamorphic rock

Rock formed by the

alteration of preexisting

rock deep within the

Earth by heat, pressure,

and/or chemically active

fluids

rock cycle

A model that illustrates

the origin of the three

basic rock types and the

interrelatedness of

Earth materials and

processes

A body of molten rock

found at depth including

any dissolved gases and

crystals

Magma that reaches the

Earth’s surface

from solution in water,

or from the secretions of

organisms and

transported by water,

wind, or glaciers

 A rock is any solid mass of

mineral or mineral-like

matter that occurs

naturally as part of our

The Rock Cycle

 Interactions among the

Earth’s water, air, and land

can cause rocks to change

from one type to another

 The continuous processes

that cause rocks to change

make up the rock cycle

 When magma

(molten material

beneath the Earth’s

surface) cools and

hardens, igneous

rocks form Magma

that reaches the

surface is called

lava

 When weathered (process

by which rocks are

physically and chemically broken down into small pieces called sediments) sediments are compacted and cemented together, they form sedimentary rocks.

 When sedimentary rocks are subjected to extreme pressure and heat, they change in metamorphic rock.

The Rock Cycle

Powers of the Earth’s Rock Cycle

 Heat from the Earth’s

interior are responsible

for forming both

igneous and

metamorphic rocks

 Weathering and the

movement of weathered

materials are generated

by the sun’s energy and

produce sedimentary

rock.

Ag Earth Science – Chapter 3.2

3.2 VOCABULARY

Latin word for “fire”

intrusive igneous rock

Igneous rock that

formed below the

Earth’s surface

extrusive igneous rock

Igneous rock that has

formed on the Earth’s

surface

basaltic composition

A compositional

group of igneous

rocks indicating that

the rock contains

substantial dark

silicate minerals and

calcium-rich

plagioclase feldspar

andesitic composition

A composition of

igneous rocks lying

between felsic and

mafic

Formation of Igneous Rocks

Igneous – Comes from

the Latin word “ignis”

which means “fire”

Formation of Igneous Rocks

Intrusive Igneous

Rocks – rocks that

form when magma

hardens (cools)

beneath the Earth’s

surface

 Example – Granite

Formation of Igneous Rocks

Extrusive Igneous

Rocks – rocks that

form when lava

hardens (cools) above

the Earth’s surface

 Example – Rhyolite

Classification of Igneous Rocks

Classification of Igneous Rocks

Classification of Igneous Rocks

Fine Grained Texture

– Rapid cooling =

small mineral grains

Small grains are said

to have “fine-grained”

texture

Classification of Igneous Rocks

Glassy Texture – Lava

Classification of Igneous Rocks

Porphyritic Texture –

Large body of magma

may take thousands

of years to harden

Variety of

temperature/cooling

within large mass =

large crystals and

fine-grained minerals

Classification of Igneous Rocks

Classification of Igneous Rocks

Basaltic Composition

– Rocks that contain

many dark silicate

minerals and

plagioclase

Classification of Igneous Rocks

Classification of Igneous Rocks

Classification of Igneous Rocks

Ag Earth Science – Chapter 3.3

3.3 VOCABULARY

clastic sedimentary rock

chemical sedimentary rock

Formation of Sedimentary Rocks

Sedimentary – Comes

from the Latin word

“sedimentum” which

means “settling”

Formation of Sedimentary Rocks

 Weathering, Erosion, and

Deposition

 Erosion – involves weathering

and the removal of rock

 When an agent (wind, ice,

water, or gravity) loses

energy, it drops the

sediments.

 Deposition – the process of

erosion losing energy and

dropping sediment.

Formation of Sedimentary Rocks

minerals are deposited

in the tiny spaces

among sediments.

Formation of Sedimentary Rocks

The 5 Main Processes

Classification of Sedimentary

Rocks

Clastic Sedimentary Rocks – Made up of weathered bits of rocks and minerals

Classification of Sedimentary

Rocks

 Classified according to particle size

 Conglomerate –(gravel) rounded, large gravel-size or larger pebbles cemented together

Classification of Sedimentary

Rocks

Chemical and Biochemical Sedimentary Rocks – form when dissolved substances

precipitate, or separate, from water solution

 Examples – limestones, rock salt, chert, flint, and rock gypsum.

Features of Some Sedimentary

 Each layer is a “time period”

 Fossils are unique in sedimentary rocks

Ag Earth Science – Chapter 3.4

3.4 VOCABULARY

contact metamorphism

Changes in rock

caused by the heat

from a nearby magma

body

hydrothermal solution

The hot, watery

solution that escapes

from the mass of

magma during later

stages of

crystallization

Formation of Metamorphic Rocks

temperatures and pressures.

 These conditions are found

a few kilometers below the

earth’s surface and extend

into the upper mantle

Formation of Metamorphic Rocks

Heat comes from

magma and change in

temperature with

depth

Agents of Metamorphism

solutions that surround

mineral grains aid in

recrystallization by

making it easier for ions

to move When hot,

water-based solutions

escape from magma,

they are called

hydrothermal solutions

These hot fluids promote

recrystallization.

Classification of Metamorphic

Rocks

Foliated Metamorphic

Rocks – a texture that

gives the rock a

layered appearance

Classification of Metamorphic

Rocks

Nonfoliated

Metamorphic Rocks –

a texture that does

not exhibit a banded

or layered

appearance