CUMBERLAND COUNTY MIDDLE SCHOOL
6TH GRADE SCIENCE
Mrs. Tabetha Cooksey
History of Earth
OCTOBER 27TH, 2014
I CAN COMPARE AND CONTRAST CONSTRUCTIVE AND DESTRUCTIVE
FORCES THAT CHANGE EARTH’S SURFACE OVER TIME.
Compare and Contrast the landforms below. Describe what you see!
(Complete sentences with use of proper grammar and punctuation.)
CONSTRUCTIVE & DESTRUCTIVE FORCES ON
LANDFORMS
TWO TYPES OF FORCES
• Destructive Forces: processes that destroy landforms.
• 2 types: Slow (weathering) and Fast (Erosion)
• Ex. landslides, volcanic eruptions, earthquakes, floods
• Constructive forces: forces that build up an existing
landform or create a new one.
• Caused by: water, gravity, wind and glaciers.
• Ex: deposition, landslides, volcanic eruptions, floods
WEATHERING
• Weathering: slow, destructive force that breaks rocks into smaller pieces called
sediments. Can by physical (mechanical) or chemical.
• Keywords: wear down, break apart
Mechanical weathering: the
breaking of rock into smaller pieces by
forces due to gravity, ice, plant roots, or
other physical forces.
CHEMICAL WEATHERING: THE CHANGING OF
MATERIALS IN A ROCK BY CHEMICAL PROCESSES.
EROSION
•
Erosion: the destructive movement of materials away from one place by wind, water, ice and
gravity.
Wave Erosion
Wind Erosion (Dust Storm)
Grand Canyon Video
LANDSLIDES
• Landslides: occur when gravity quickly pulls rock and dirt
downhill.
FLOODS
• Floods: a great flow of water over an area that is usually dry
land.
VOLCANIC ERUPTIONS
• Volcano: an opening in
the Earth’s crust through
which steam, lava and
ashes erupt.
• Cause both destructive
and constructive changes
to landforms.
MOUNT ST. HELENS
Mount St. Helens Video
Saint Helen’s Before
Saint Helen’s After
Volcanoes can be constructive, but also destructive…
EARTHQUAKES
• Earthquakes: the shaking
of Earth’s surface caused
by the release of energy
along a fault.
San Andreas Fault, California
VOLCANOES & EARTHQUAKES
Tectonic Plates, Volcanoes & Earthquakes
EROSION & DEPOSITION
• Deposition: the placing of materials in a
new place (constructive force).
• Ex. Sandbars
WATER EROSION & DEPOSITION
• River Delta- Deposits of
sediment at the mouth of
the Mississippi River
creating new land called a
delta.
WIND EROSION & DEPOSITION
• Sand Dunes- sand is moved by wind
Desert Sand Dunes
Ocean Sand Dunes
OCTOBER 30TH, 2014
I CAN COMPARE AND CONTRAST CONSTRUCTIVE AND DESTRUCTIVE
FORCES THAT CHANGE EARTH’S SURFACE OVER TIME.
Compare and Contrast the landforms below. Describe what you see!
(Complete sentences with use of proper grammar and punctuation.)
OCTOBER 30TH, 2014
I CAN COMPARE AND CONTRAST CONSTRUCTIVE AND DESTRUCTIVE
FORCES THAT CHANGE EARTH’S SURFACE OVER TIME.
Classify the following as a YOUNG stream, Mature stream, or Old Stream —Explain why?
Chapter 9 Water Erosion and Deposition
Define run off, channel, sheet erosion, drainage basin, meander
Focus and produce a reflection of the “Stages of Stream Development”
OCTOBER 31ST, 2014
I CAN COMPARE AND CONTRAST CONSTRUCTIVE AND DESTRUCTIVE
FORCES THAT CHANGE EARTH’S SURFACE OVER TIME.
Change is everything. Describe how your community has changed over time.
Be sure to include descriptions of weathering processes, erosion, and
deposition.
Kinetic City: Shape It Up
Webrangers Activity: Rock Around the Park
Weathering and Erosion Webquest - Mr. Pierce Online
NOVEMBER 3RD, 2014
I CAN COMPARE AND CONTRAST CONSTRUCTIVE AND DESTRUCTIVE
FORCES THAT CHANGE EARTH’S SURFACE OVER TIME.
Compare and contrast the two scenes. Using geological terms, describe how
these changes occurred…..
Physical Weathering
PHYSICAL
AND
CHEMICAL
Earth Science
I. BASIC DEFINITIONS
• 1. WEATHERING-The physical and
chemical breakdown of rock into smaller
particles called sediment.
BASIC DEFINITIONS
•2. EROSION- A process by which weathered
sediments are carried and transported.
Sediment may get
transported thousands of
miles by one of the world's
major rivers, or it may just go
from the top of the hill to the
bottom during a landslide.
During this journey, a lot can
happen to the sediment.
BASIC DEFINITIONS
3.
• DEPOSITION-The process by which
sediment is dropped off and settles.
think
“deposit”
PREVIOUS KNOWLEDGE: SURFACE AREA
•
Def: A measure of how much exposed area a solid object has.
•
As a rock breaks into smaller pieces, (see diagram below), what happens to the
overall surface area of that rock?
Least
surface
area
Most
surface
area
MINI DEMO
Which beaker will “weather” the alka-seltzer quicker? Why?
BEAKER #1
• BEAKER #2
-1 circular tablet of AlkaSeltzer
-1 crushed up tablet of Alkaseltzer
II. TYPES OF WEATHERING
•
1. _______________________  occurs
PHYSICAL WEATHERING
when rock is cracked, split, or
broken into smaller pieces of the same material without
changing composition.
A. TEMPERATURE CHANGE
• 1. Rocks are heated by the sun. As the outside
of the rock is heated, its surface begins to
________. expand
• 2. As temperatures fall at night, the outside of
the rock _________. contract
• 3. This cycle of heating and cooling of the rock’s
surface, causes slabs or layers of rock to break
off. (CLICK HERE  ANIMATION)
• THIS PROCESS IS CALLED: ______________
exfoliation
animation
http://www.as.uky.edu/academics/departments_programs/EarthEnvironmentalSciences/EarthEnvironmentalSciences/Educational%20Materials/Documents/elearning/module07swf.swf
EXFOLIATION
Exfoliation: peeling away of rock layer
Exfoliation: peeling away of rock layer
Exfoliation: peeling away of rock layer
Exfoliation: peeling away of rock layer
B. FROST ACTION AKA (FROST WEDGING)
• 1. This process occurs when
water seeps into the cracks
in a rock.
• 2. When water freezes (into
ice), it ____________
expands by 9%
3. This cycle of freezing and
melting causes the rock
to split or break apart.
B. FROST ACTION AKA (FROST WEDGING)
● example from real life
- filling a water bottle/garbage pail
to the top then freezing it  it
may crack or break
• 4. The same process happens to our
roads during the winter months and
pot holes
creates ___________.
• (CLICK HERE  ANIMATION)
FROST WEDGING
Frost Wedging: this melting and freezing
cycle eventually may split rocks
Frost Wedging: this melting and freezing
cycle eventually may split rocks
Pot Holes: a common form of frost wedging
Pot Holes: a common form of frost wedging
C. ORGANIC ACTIVITY (PLANT/ANIMAL ACTION)
• 1. The activities of organisms,
including plants, burrowing animals,
and humans, can also cause
mechanical weathering.
• Trees and shrubs can grow through
the cracks in rocks, splitting the rock.
• As they grow, their roots wedge apart
the rocks.
C. ORGANIC ACTIVITY (PLANT/ANIMAL ACTION)
• Even moss and lichen wedge their
tiny hair-like roots between the grains
of the rock.
• Burrowing organisms like rodents,
earthworms, & ants, bring material to
the surface were it can be exposed to
the agents of weathering..
PLANT/ANIMAL
ACTIVITY
Plant Activity: Roots Split Rock
Plant Activity: Roots Split Rock
Animal Activity: Lichens on rock
D. ABRASION
• 1. Abrasion is the breakdown of rocks caused by friction.
• As moving sand, pebbles, and larger rocks grind and
scrape against one another, these rocks are worn away.
• Can you explain how sand is a product of abrasion?
• This is how rocks often become rounded.
ABRASION
OF WIND AND WATER
Formed by marine abrasion
Formed by wind abrasion
(Utah)
Formed by wind abrasion
Valley of Fire State Park (Nevada)
Formed by wind abrasion
Arches Nation Park (Utah)
SUMMARY QUESTIONS
The following six pictures show various forms of mechanical
weathering.
Using your notes, label each picture with the appropriate
mechanical weathering method.
NOVEMBER 5TH, 2014
I CAN COMPARE AND CONTRAST CONSTRUCTIVE AND DESTRUCTIVE
FORCES THAT CHANGE EARTH’S SURFACE OVER TIME.
Identify as being an example of WEATHERING, EROSION, or DEPOSITION
1. Flood water pounding against a canyon wall and wearing it down.
2. Rain washing away soil from a hillside.
3. Layers of sediment forming at the bottom of the ocean.
4. A mudslide flowing down a steep hill
5. Glaciers dropping rock and sand to form moraines.
6. Waves dropping sand on the beach
7. Caves being formed by acid rain dissolving underground limestone.
8. Deltas forming at the mouth of rivers.
Physical or Chemical Weathering: Breaking or Baking?
WEATHERING, EROSION, & DEPOSITION
SORTING ACTIVITY--ANSWERS
1.
2.
3.
4.
5.
6.
7.
8.
Weathering
Erosion
Deposition
Erosion
Deposition
Deposition
Weathering
Deposition
NOVEMBER 6TH, 2014
I CAN COMPARE AND CONTRAST CONSTRUCTIVE AND DESTRUCTIVE
FORCES THAT CHANGE EARTH’S SURFACE OVER TIME.
Formative Assessment Physical/Mechanical Weathering
Number your notebook 1-6. You will be presented with 6 images. You will need to
DESCRIBE what you see and IDENTIFY what mechanical process is shown…
Physical or Chemical Weathering: Breaking or Baking?
WHICH METHOD OF MECHANICAL WEATHERING IS SHOWN
BELOW?
_______________________
ORGANIC/ROOT WEDGING
WHICH METHOD OF MECHANICAL WEATHERING IS SHOWN
BELOW?
_______________________
FROST/ICE WEDGING
WHICH METHOD OF MECHANICAL WEATHERING IS SHOWN
BELOW?
_______________________
FROST/ICE WEDGING
WHICH METHOD OF MECHANICAL WEATHERING IS SHOWN
BELOW?
_______________________
ABRASION
WHICH METHOD OF MECHANICAL WEATHERING IS SHOWN
BELOW?
_______________________
EXFOLIATION
WHICH METHOD OF MECHANICAL WEATHERING IS SHOWN
BELOW?
_______________________
FROST/ICE WEDGING
JUST FOR YOUR ENJOYMENT!
Physical or Chemical Weathering: Breaking or Baking?
PLEASE PLAY!
Results in
exfoliation
of rock
Rocks expand
during day,
contract at
night
Repeated
cycles of
freeze/thaw
periods
Temperature Change
Results in the
breaking and
cracking of
rocks
Frost Wedging
Mechanical
Weathering
Plant/Animal Activity
Affected by
burrowing
animals, plant
roots, and
humans
Tree roots
wedge in the
cracks of rocks
and split them
Abrasion
There must be
some sort of
friction or
contact
Wind, water, and
ice are the most
common forms
of abrasion
II. TYPES OF WEATHERING
CHEMICAL WEATHERING
•
1. _______________________  the breakdown of rock through a change in mineral or
chemical composition.
A. CARBONATION
carbon dioxide in the atmosphere dissolves in
• Occurs when _______________
the droplets of water that make up a cloud.
“carbonic acid”
• This mixture forms a weak ____________ that dissolves certain
marble
rocks and minerals, some which include limestone
__________, ________,
chalk.
and _______.
Carbonation reaction = (carbon dioxide + water)
GUIDED PRACTICE
• Which minerals will dissolve in
the presence of carbonic acid
in each of these rocks:
ANSWERS
a) limestone
b) marble
calcite
a) limestone ____________
calcite/dolomite
b) mable  ______________
(hint  use your ESRT to look up the
mineral composition of each rock)
CHEMICAL WEATHERING OF MARBLE
A RESULT OF THIS TYPE OF CHEMICAL WEATHERING IS THE
FORMATION OF CAVERNS OR CAVES!
•
Using map symbols in your ESRT,
describe what type of bedrock this is.
_____________
limestone
•
Carbonic acid rain water seeps into
the limestone bedrock through
cracks. The carbonic acid dissolves
the limestone which is carried away
by water.
•
A cave (cavern) forms by this
process. Cavern features include:
1. Sink Holes
2. Stalactites (c= ceiling)
3. Stalagmites (g=ground)
SINK HOLES
• Are common where the rock
below the land surface is
limestone, carbonate rock,
salt beds, or rocks that can
naturally be dissolved by
ground water circulating
through them.
• The most damage from
sinkholes tends to occur in
Florida, Texas, Alabama,
Missouri, Kentucky,
Tennessee, and Pennsylvania.
STALACTITES VS. STALAGMITES
• Stalactites- an icicle shaped
mass of calcite attached to
the ceiling of a limestone
cavern.
• Stalagmite-a cone of calcite
rising from the ground of a
cavern .
• Usually come in vertical pairs
B. HYDROLYSIS
• The chemical weathering by reaction of
water
_________
with other substances.
• very slow process
• Ex: the rock granite is stable in dry
climates, but in moist/wet climates,
rainfall dissolves the mineral feldspar in
granite.
• Feldspar becomes a clay mineral
(kaolinite) and weakens the bond
between the other minerals.
“Cleopatra’s Needle”  Granite Rock Statue
Egypt, 1880
NYC, present
C. OXIDATION
•
oxygen from the
A chemical reaction when ____________
atmosphere combines with certain minerals in a
rock.
•
Ex: When oxygen combines with iron, iron oxide or
‘rust” forms.
• (Iron + oxygen) = iron-oxide (rust)
•
This chemical change weakens the rock, and the
rock begins to crumble.
•
Oxidation in the presence of water takes on a
reddish- yellow brown color.
D. PLANT ACIDS
• Acids from decaying organic matter mix with groundwater
and aid in dissolving rocks.
• Plant acids are produced by both plants and animals.
E. MAN-MADE ACIDS
• Forms when man-made gases (sulfur dioxide and nitrogen oxides)
produced by burning fossil fuels dissolve in the droplets of water
that make up clouds.
• This causes the rainwater to become
• ________________
Sulfuric acid (H2S04)
• ________________ (HN03)
Nitric acid
Types of acid
rain
ACID RAIN IS A SERIOUS ENVIRONMENTAL PROBLEM THAT AFFECTS
LARGE PARTS OF THE UNITED STATES AND CANADA. ACID RAIN IS
PARTICULARLY DAMAGING TO LAKES, STREAMS, AND FORESTS AND THE
PLANTS AND ANIMALS THAT LIVE IN THESE ECOSYSTEMS. IN ADDITION,
ACID RAIN ACCELERATES THE DECAY OF BUILDING MATERIALS AND
PAINTS, INCLUDING IRREPLACEABLE BUILDINGS, STATUES, AND
SCULPTURES THAT ARE PART OF OUR NATION'S CULTURAL HERITAGE.
USEPA
SUMMARY QUESTIONS
•
1. Explain the difference between mechanical and
chemical weathering.
•
2. List the 5 methods of chemical weathering.
•
3. Describe the type of environment that hydrolysis is
effected most by.
•
4. Describe how humans contribute to the process of
chemical weathering.
ANSWERS
Q: Explain the difference between mechanical and chemical weathering.
1: Mechanical weathering is the
breaking down of material by size
and shape only and chemical
weathering is altering material by
composition.
ANSWERS
Q: List 5 methods of chemical weathering.
2:
1)carbonation
2) hydrolysis
3)oxidation
4) plant acids
5) man-made acids
ANSWERS
Q: State how the surface area of a rock is
affected by mechanical weathering?
3: Typically moist/wet climates where
there is much rainfall.
ANSWERS
Q: Describe how humans contribute to the
process of chemical weathering.
4: Humans produce man-made
gasses by burning so much fossil
fuel (coal, oil, natural gas). These
gases react with water and produce
acid rain. This acid rain literally
“eats” away at rocks and affects
other parts of our ecosystem as well.
NOVEMBER 12TH, 2014
I CAN COMPARE AND CONTRAST CONSTRUCTIVE AND DESTRUCTIVE
FORCES THAT CHANGE EARTH’S SURFACE OVER TIME.
Identify the action or process as being an example of physical or chemical weathering..
1. Burning the boxes and paper.
2. Can of coke freezing outside,
3. Layer of rock falls down the hill.
4. Bike rusts after being in the rain.
5. Add water to break the bond and form clay.
6. Sandblasting the statue.
7. Stalactites hanging from the cave ceiling
8. Tree growing up through the pavement
NOVEMBER 14TH, 2014
I CAN DESCRIBE THE ROLE OF WATER BOTH ON LAND AND
UNDERGROUND.
Based on the Ag Mobile yesterday….
Illustrate and describe the soil profile (layers of soil)
Describe the waterways in the following images.
NOVEMBER 17TH, 2014
RECAP LT #1
Weathering, Erosion, and Deposition FA
Draw a table on the back of teach formative sheet and fill in the blanks
Agent
Freezing Thawing
Type
Description
Mechanical/Physical
Rock particles wear away particles.
Chemical
Forms from coal, oil, and gas burning.
Breaks rocks by ice wedging
Forms carbonic acid in water
Weathers marble and limestone
Burrowing in the ground breaks rock
Causes rust on some rocks
Causes rock to flak off in layers
Mass Movement "Slip, Sliding Away....“
After viewing the video, describe each type of mass
movement and in your
own words what exactly occurs with each. Use
descriptions from the video.
NOVEMBER 19TH, 2014
RECAP LT#1
Identify the type of weathering and how it works 
1
2
5
3
7
6
9
4
8
10
You have until 11:25!!!
PHYSICAL WEATHERING--EXFOLIATION
When a rock has heat exerted upon it, along with
pressure, it separates into layers.
PHYSICAL WEATHERING—ICE/FROST
WEDGING
When water leaks into the cracks of rocks, it freezes and
causes the rock to break.
PHYSICAL WEATHERING—ROOT/ORGANIC WEDGING
This occurs when burrowing animals, humans, or plants
interfere and work their way into rocks.
PHYSICAL WEATHERING--ABRASION
Abrasion occurs when rocks rub against each
other and become rounded.
CHEMICAL WEATHERING--HYDROLYSIS
When rocks sit in water for extended periods of
time they begin to break down and have a claylike texture.
CHEMICAL WEATHERING--OXIDATION
When oxygen reacts with iron in rocks, they rust, taking on a
red-orange color.
CHEMICAL WEATHERING--DISSOLUTION
Rocks, when in water, react with acids in the water and
dissolve. A clue that this has happened to a rock is the
presence of small holes.
CHEMICAL WEATHERING--CARBONATION
• -Water absorbs carbon dioxide when rain falls or from
decaying organic material. The carbon dioxide dissolved
in water forms carbonic acid that reacts with many
common minerals.
CHEMICAL WEATHERING-MAN-MADE (ACID
RAIN/PRECIPITATION)
• Water in the atmosphere absorbs sulfur oxides and
nitrogen oxides. Through a series of chemical reactions
these pollutants are converted into acids that are a cause
of acid precipitation.
CHEMICAL WEATHERING--PLANT (ORGANIC) ACID
• When plants decay they release acids that react with the
minerals in rocks.
NOVEMBER 20TH, 2014
I CAN DESCRIBE THE ROLES OF WATER BOTH ON LAND AND UNDERGROUND
The mountain peaks shown below were initially formed millions of years ago through
the processes of folding, faulting, and over thrusting.
Describe 2 “physical” weathering processes that would occur to affect the mountains.
Describe 2 “chemical” weathering processes that would occur to affect the mountain.
How does erosion and deposition play a role?
NOVEMBER 21ST, 2014
I CAN DESCRIBE THE ROLES OF WATER BOTH ON LAND AND UNDERGROUND
Fast Processes the Change Earth Surface
Early Earth and Plate Tectonics
You will need your study guide and chapter note-taking packet