Transcript Erosion & Deposition

Tuesday
1. Layer 4 in the diagram has the greatest temperature and
pressure. What part of the Earth is labeled layer 4?
A. crust
B. mantle
C. outer core
D. inner core
2. Ricardo has a sedimentary rock in his rock collection, which
contains ancient snail fossils. Where did this rock MOST
LIKELY form?
A. in a volcano
B. around a magma chamber
C. on the ocean floor
D. at the beach
Tuesday
3. Students want to identify a rock in a nearby field. Which
of the following properties would be most useful in
identifying the unknown rock?
A. Luster
B. Smell
C. Mineral Content
D. Specific Weight
4. Igneous rock forms from
A. compaction and cementation of sediments.
B. weathering and erosion of other rocks.
C. magma deep within the Earth.
D. evaporation of water from a pond.
Erosion &
Deposition
Erosion & Deposition:
Standard:
S6E5: Students will investigate the scientific
view of how the earth's surface is formed.
Element:
d. Describe processes that change rocks and
the surface of the earth.
e. Explain the effects of physical processes
(plate tectonics, erosion, deposition, volcanic
eruption, gravity) on geological features.
Essential Questions:
1)
2)
3)
4)
5)
What is erosion?
What causes erosion?
What is deposition?
What causes deposition?
What are the effects of erosion and
deposition?
What is erosion?
Erosion is a natural process of
moving weathered rock and soil to
another place. Erosion has a constant
impact on Earth’s surface. Over millions
of years, it wears down mountains by
removing byproducts of weathering
and depositing them elsewhere
Causes of Erosion:
• Gravity constantly pulls material
downward.
• Water such as rainwater,water from
melting snow, rivers, streams, and waves
carry rock and soil particles.
• Winds move small particles of dust
through the air and larger particles of
sand along the ground.
• Ice, in the form of glaciers, transport rock
and soil particles as they move downhill.
What is deposition?
Deposition is a natural process of
laying down or depositing sediment in new
locations.
Deposition occurs when:
a) wind slows down or stops blowing.
b) water slows down or stops moving.
c) glaciers melt.
Gravity and Mass Movement
Mass movement is the downhill
movements of rock and soil. Gravity
pulls material downward. A triggering
event, such as heavy rain or an
earthquake might loosen the rock and
soil. As the material becomes looser, it
gives way to the pull of gravity and
moves downward.
Examples of Mass Wasting
Landslide – a sudden fast movement of
rock and soil
Insane landslide in California
https://www.youtube.com/watc
h?v=qEbYpts0Onw
https://www.youtube.com
/watch?v=Y6vs_lnBqwY
Examples of Mass Wasting
Rockfall – individual blocks of rock drop
suddenly and fall freely down a
mountainside
Italian landslide:
Huge boulders
destroy buildings
in South Tyrol
https://www.youtu
be.com/watch?v=
-5SiQqSroIw
http://atlas.nrcan.gc.ca/site/english/maps/environment/naturalhazards/landslides/fig_2_land_rockfall.jpg
Examples of Mass Wasting
Rockslide – a large mass of rock slides as a
unit down a slope
http://data2.collectionscanada.ca/ap/a/a131072.jpg
Examples of Mass Wasting
Mudflow – debris, or a mixture of rock, soil,
and plants with a a large amount of water
http://www.fas.org/irp/imint/docs/rst/Sect3/img004.jpg
www.uwsp.edu/geo/faculty/ritter/images/lithos
...
Example of Mass Wasting
Creep – slow downhill movement of
rock and soil
https://www.youtube.com/watch?v=9C1fW
4hWLUM
The diagram shows how the hillside slowly
slips over time.
1. What landform is
pictured?
2. What caused the
landform?
https://
www.y
outube
.com/w
atch?v
=fRUri
croxcc
http://ejordan0998.blogspot.com/2010/12/mass-movement-soil-creep.html
Mass wasting by an avalanche. It is similar to
a landslide with ice and snow instead of rock.
cause
Notes pg. 6
Water
Water in all its forms causes erosion.
Raindrops (especially in dry environments)
create splash erosion that moves tiny particles
of soil. Water collecting on the surface of the
soil collects as it moves towards tiny rivulets
and streams and creates sheet erosion.
Streams and rivers move sediments. The
faster water moves, the larger the objects it
can pick up and transport.
Features caused by Water Erosion
River ValleyV-shaped valley
formed when
water flows
quickly down
a steep slope
Features caused by Water Erosion
https://www.youtube.com/watch?v=eShAgvcnsP0
The Grand Canyon
Features caused by Water Erosion
Mesa
Buttes are tall, steep-sided towers of rock.
Buttes are created by erosion. They were
formerly part of flat, raised sections of land
known as mesas or plateaus.
As streams slowly cut through
a plateau, they create flat-topped,
rocky areas known as outliers. A
large outlier is called a mesa. A
tower-like outlier is called a butte.
Butte
Mesa
Features caused by Water Erosion
Mesa
When a river flows
over more gently
sloping land, it
spreads out and
erodes the land. The
flat, wide areas of land
along a river is a flood
plain.
https://www.youtube.com/watch?v=qEz4Mi
OVTMM
Features caused by Water Deposition
Alluvial Fan
Delta
web.cortland.edu/gleasong/phgsg3.html
Alluvial Fan- landform formed
when sediment is deposited where
a stream leaves a mountain range
http://www.geo.uu.nl/fg/palaeogeography/pictures/delta_evolution/delta.jpg
Delta- landform formed when
sediment is deposited where a
river flows into an ocean or lake
Features caused by Water Deposition
southgakayakfishing.blogspot.com
http://www.fws.gov/midwest/BigMuddy/images/jameson_sandbars.jpg
River sandbars are formed when rivers curve and slow
down, dropping sediments.
Features caused by Water Deposition
Incoming waves deposit sand to form ocean sandbars –
long ridges of sand parallel to the shore
Features caused by Water Deposition
Mesa
Flooding causes a
river to rise above its
banks and spread out
over its flood plain.
When the flood water
finally retreats, it
deposits sediment as
new soil.
Features caused by Water Deposition
Beach (shoreline) – landform formed when waves
deposit sediments along a coast or shore
tripadvisor.com
Two Ways To Make A Dune
https://www.youtube.com/watch?v=5W3_y
5_3w9A
notjustgeorgia.com
Features caused by Water Deposition
http://www.n-georgia.com/images/costIslndWeb.jpg
Jekyll Island
Jekyll Island, at 5,700 acres, is the
smallest of Georgia's barrier islands. The
western side of Jekyll Island is fronted by
Jekyll Creek and salt marsh, and the
eastern edge of the island is defined by its
beach and the Atlantic Ocean.
http://www.georgiaencyclopedia.org/nge/Multimedia.jsp?id=m-2086
Barrier Islands – storm
waves pile up large
amounts of sand
above sea level
forming a long narrow
island parallel to the
coast
1.
2.
What landform is pictured?
What caused the landform?
Erosion &
Deposition
Ice
Glaciers are large masses of ice that
move over land. On a mountain, the
weight of a heavy mass of ice causes it
to flow downward, usually slowly. On
flatter land, the ice spreads out as a
sheet. As glaciers form, move, and
melt away they shape landscapes.
Feature caused by Erosion by Glaciers
Valley glaciers form in mountains and flow
down through valleys. This is a picture of
a glacier which carves out a U-shaped
valley where it flows dragging rocks and
boulders along the way.
Continental Ice Sheets
A continental ice sheet or glacier (Greenland, below)
is a vast expanse of ice which completely covers all
underlying terrain. They form in mountainous or nonmountainous regions and spread outward in all
directions.
www.homepage.montana.edu/.../ContinentalIce.jpg
Features caused by Deposition by Glaciers
Glaciers deposit till (sediments)
called moraines.
Till is the mixture of sediments that a
glacier deposits directly on the
surface. Till can be clay, silt, sand,
gravel, and boulders.
Glaciers leave
depressions that
become filled with
water to form bowlshaped lakes, called
kettle lakes.
www.arctic.uoguelph.ca/.../pic36.jpg
http://nsidc.org/glaciers/gallery/images/bylot_island_valley_large.jpg
http://capenews.net/blogs/latitude_somewhere/20
09/11/29/west-barnstabel-conservation-area/
Till deposited by glaciers.
http://faculty.unlv.edu/lachniet/Glaciers%20and%20ELA.html
A striated and faceted limestone
boulder in glacial till clearly
demonstrates the presence of a
former ice cap in the Sierra
Cuchumatanes. (Western
Gautamala)
pubs.usgs.gov
Features caused by Water Erosion
caves
http://www.arenal.net/tour/venado-caves/images/cave_tour_pic.jpg
sinkholes
http://www.sewerhistory.org/images/mi/min/min_spd1.jpg
Wind
Wind has the power to transport and deposit
sediment. It can shape landforms, especially in
dry regions and in areas that have few or no
plants to hold soil in place. Wind can build up
dunes, deposit layers of dust, or make a land
surface as hard as pavement.
The Work Of The Wind
https://www.youtube.com/w
atch?v=VXDKLUA4lpE
Features caused by Wind Erosion &
Deposition
Sand Dune - hill, mound, or ridge of
windblown sand
www.travelblog.org/.../tb_mui_ne_sand_dunes.jpg
http://ngm.nationalgeographic.com/2012/11/sand-dunes/steinmetz-photography#/01-lut-desert-dasht-e-lut-iran-670.jpg
Features caused by Wind Erosion &
Deposition
Loess – deposits of dust or silt
Desert Pavement – wind blows dust
away, leaving only larger rocks
http://www.backyardnature.net/loess/vertbluf.jpg
http://pubs.usgs.gov/of/2004/1007/images/pavement2.gif
These rocks have been blasted by wind and
sand causing them to become rounded.
WIND ABRASION
Bottom of Pg. 9
• The wind hits a boulder.
• It deposits the sediment.
• Wind removes sand and other sediment
from the ground by the process of erosion.
• As the sediment piles up.
• Piles of sediment cause sand dunes to
forms.