Earth Surface changes• Changes to Earth’s surface happen over time.• Some changes are due cataclysmic events like

volcanoes erupting, or earthquakes.• These changes are fast and violent.

Slow changes

• Other forces change Earth slowly.• The sun’s energy drives wind, water,

temperature changes, and life forms that can change the Earth.

• Slow changes are called weathering.

Physical Weathering

• The Earth’s surface is made of rock and soil.• Rocks form from different processes.

Minerals

• Rocks are made of minerals. • Minerals are elements that have been

combined together by chemical reactions.• Some minerals are pure like gold and some

minerals are combinations like salt.

Properties

• Minerals have different physical properties. 1.Color2.Luster3.Hardness4.Streak5.Cleavage

mineral id 9:48

Mohs Hardness Scale

• A way to identify minerals is to use the scratch test and identify the mineral with a scale.

• What other ways could you use to identify minerals?

Rocks

• Minerals combine to form rocks. Scientists classify rocks according to how they are formed.

Igneous Rocks

• When magma cools igneous rocks form.• You can identify igneous rocks by the crystals

or holes formed by gas bubbles.• Most dark colored rocks are igneous.

graniteobsidian Pumice

Sedimentary

• Formed by sediments.• Sediments are pressed and cemented

together.• May contain fossils.

sandstone

Metamorphic

• Rocks that are pushed underground deep into the crust can be heated again.

• Sedimentary and igneous rocks that are reheated can change into igneous rocks.

• Look for ribbonlike layers. gneiss

Rock Cycle

• Rocks can go from one type to another by the rock cycle.

Rock cycle

rock cycle vid

Rock cyclegeology kitchen

Rock cycle

Weathering by water

• Water causes weathering by 1.Freezing and cracking rocks2.Water in rivers and streams makes rocks in

the water move. Rocks break into smaller pieces.

3.Water carries sand or pebbles that will rub against rocks and wear them down.

rock weathering video

Weathering by wind

• Wind picks up sand and blows the sand against rock.

• The wind wears down the rock and changes the rock.

Living things

• Roots and plants grow in cracks in rocks and widen cracks in the rock and break them up.

Chemical Weathering

• Rainwater and groundwater join with carbon dioxide gas from the air to form a weak acid.

• The acid wears away the rock.• Forms caves over time.• Caves form in sedimentary rock (limestone)

Soil

• Soil is made of layers.• The layers are different from other layers.1.Undecayed (humus)2.Topsoil: loose rich soil, holds lots of humus

and minerals. Good for plants.3.Subsoil: Holds many minerals, where you find

clay.4.Rock: Weathered rock and bedrock

Layers of the Soil

Running Water

• Gravity makes the water move. Loose soil gets pulled in the water.

• The draining water is called runoff. Runoff carries soil, sand, and small rocks.

• The runoff deposits sediments at the bottom of the river, this is called deposition.

Waves

• Waves pound on the shore.• Energy in the wave break up rocks into smaller

rocks.• Change rough rocks to smooth rocks.• The wave action will erode away the

shoreline.• Makes haystacks on the Washington and

Oregon coast.

Gravity and Mass movement

• Gravity pulls large masses down mountains and hills.

• This mass movement in the mountains are called avalanches.

• The mass movement in hills are called landslides or mudslides.

• Can happen fast like a mudflow or slow with creep.

Groundwater

• When rain falls or ice melts some of the water goes into the ground.

• Water will mix with CO2 to form a weak acid that weathers the limestone.

• Water will seep into tiny holes in the rocks.• Groundwater will form caves.• Water evaporates leaving minerals that build

stalagmites and stalagtites.

Wind

• Strong winds pick up sand, and small pebbles.• These winds can weather rock. Rocks will break

into smaller rocks.• Erosion happens when these smaller rocks and

sand move from the power of the wind.• When winds slow down, the sand and dirt is

deposited in a new place.• The Dust bowl happened when there was a lot of wind

blowing dust. The topsoil needed to grow food was deposited hundreds of miles away.

Glaciers

• Large masses of water that are on mountains.• We depend on glaciers for our water and

electricity.• Glaciers move slowly because of gravity.• Glaciers push snow, sands, and rocks ahead of it

called glacial till.• Valley glaciers carve out the valleys on

mountains.• Glaciers cover 10% of the Earth’s land.

Weathering and Erosion

• What is the difference?

Bill Nye

What formed the Grand Canyon?

river formations

Fossils

• Form in sedimentary rock.• We use fossils to learn about the past. Some

fossils have been dated to be hundreds of millions years old.

• Fossils give us clues about Earth’s history.

Trace fossils

• Tell us how and where an organism lived.

• Tracks, burrows, nests, animal waste, tooth marks are all trace fossils.

Body Fossils

• Show us what the plant or animal looked like.

• Petrified fossils: minerals in groundwater seep into the remains and harden.

• Most dinosaur fossils are body fossils.

Mold Fossils

• Plants or animals are covered by sediments.

• Sediments harden and turn into rock.

• Groundwater dissolves the organism.

• A hollow space is left.

Amber fossils

• Insects become trapped in tree sap.

• Insects are preserved when the sap hardens into amber.

dino dna

Erosion Jigsaw

• Each group will be assigned a reading section in the Erosion delta reader.

• Each member needs to read the section and take notes in their journal.

• Once all notes are taken, the group will design a poster that highlights the most important information. (The poster has to have words and pictures on it. Font needs to be Word Wall size.

• Reporter and a partner will present to the class.• Class will take notes.

Groups

• Group 1 – Running water pg. 9• Group 2 – Waves pg. 10• Group 3 – Gravity and mass movement pg 11• Group 4 – Groundwater (12)• Group 5 – Wind (12-13)• Group 6 – Glaciers (Glaciers)

What formed the Grand Canyon?

Claim: Scientists believe that the grand canyon was formed from the Colorado River.

Evidence: Use evidence from your lab to explain how they could come to that conclusion.

Possible Evidence• Draw picture• Use vocab from the landforms sheet

Weathering and Erosion Wrap up