Mrs. Wright Hugh B. Bain Middle School Cranston, RI SLOW
Processes that Shape the Earth PART 1. WEATHERING Slide 2 Earth -
developed over long periods of time through continual change
processes. STUDENTS: Evaluate slow processes of 1) weathering 2)
erosion and 3) mountain building. The following slides are on
weathering. Determine how the earth has changed and will continue
to change over time. Slide 3 Weathering What is it? Mechanical
(physical) and chemical processes that break down rock at Earths
surface Mechanical Weathering Chemical Weathering rock physically
broken into smaller pieces rock breaks down from exposure to water
and atmospheric gases (CO 2, O 2, and H 2 O vapor). uk
stonehenge.jpg Slide 4 What is it? Type of weathering where rock is
physically broken into smaller pieces Mechanical Weathering Slide 5
Causes of Mechanical Weathering Freezing & Thawing Release of
Pressure Plant Growth Action of Animals Abrasion Slide 6 Freezing
& Thawing Ice wedging Water freezes in crack in rock Expands
and makes crack bigger Process also causes cracks in sidewalks
& potholes in streets
http://mail.colonial.net/~hkaiter/science%20images/frostwedging.gif
Slide 7 Freezing & Thawing
http://images.suite101.com/88099_brokenrk.jpg
http://www.google.com/imgres?imgurl=http://upload.wikimedi
a.org/wikipedia/commons/e/eb/Pothole_Small.jpg&imgrefurl Slide
8 Release of Pressure Erosion removes material from rock Pressure
on rock is reduced Causes outside of rock to flake off like layers
of onion
http://www.google.com/imgres?imgurl=http://environment11.pbworks.co
m/f/1273571046/exfoliation1.jpg&imgrefurl Slide 9 Plant Growth
Roots enter cracks in rocks Grow Force cracks farther apart or pry
them apart
http://www.google.com/imgres?imgurl=http://video.ecb.org/badger/download/vlc/images/VLC161_Roo
ts_breaking_rocks.jpg&imgrefurl Slide 10
http://www.google.com/imgres?imgurl=http://www.wkmctv.com/geo_images/root_wedging.jpg&imgrefurl
Plant Growth Slide 11 Action of Animals Burrowing animals loosen
and break apart rocks in soil beeholes.jpg
http://www.google.com/imgres?imgurl Slide 12 Water vole burrows
brook-meadow.hampshire.org.uk Burrowing frog 090629081133 large.jpg
Action of Animals Water Vole.jpg 567 438 - Water Vole
dungevalley.co.uk Slide 13 http://dirttime.ws/Photos/IM002689.jpg
Action of Animals http://timenewsfeed.files.wordpress.
com/2010/11/106302684.jpg Slide 14 Abrasion grinding away of rock
by rock particles carried by water, ice, wind or gravity What is
it? riverrocks.jpg Slide 15 Abrasion Sand & rock particles
carried by wind & water, wear away exposed rock like sandpaper
on wood. image002.jpgimage002.jpg 569 358 - wave action (mechanical
weathering) photo courtesy of R. Weller skywalker.cochise.edu Slide
16 What is it? Type of weathering where rock breaks down from
exposure to water and atmospheric gases (CO 2, O 2, and H 2 O
vapor). Chemical Weathering Slide 17 Causes of Chemical Weathering
Action of Water Oxygen (Oxidation) Carbon dioxide (CO 2 ) Living
Organisms Acid Rain Slide 18 Action of Water Most important cause
of chemical weathering Dissolves rock
3572473_f520.jpg3572473_f520.jpg 520 390 -... formed by chemical
weathering. Water dissolves the calcites in the rock...
hubpages.com Slide 19 Action of Water 278.Jpg278.Jpg form where
water collects and accentuates rates of chemical weathering
uregina.ca Slide 20 Oxygen (Oxidation) Iron (Fe), or other metal,
combines with oxygen in the presence of water If metal is Fe,
causes rust Rock containing iron also rusts then crumbles apart
Rusting causes Red/brown color What is it? jimeno2.glogster.com
Slide 21 Carbon dioxide (CO 2 ) CO 2 dissolves in rainwater Forms
carbonic acid that seeps into soil Easily weathers rocks like
limestone & marble chemical weathering process 3.1 800X800.jpg
Rain water and carbon dioxide create carbonic acid. This mild acid
interacts... ehow.co.uk Slide 22 Carbon dioxide (CO 2 ) Cheddar
caves xtrawide.jpg... loses some of its dissolved carbon dioxide
and deposits some of its... geolsoc.org.uk Water seeped into cracks
in limestone & cracks enlarged gradually Rainwater became
acidic as it dissolved carbon dioxide from the air and soil
Dissolved away rock to form cave system Water dripping from cracks
in cave roof, lost dissolved CO 2 & depositsCaCO 3 Formed
stalactites, stalagmites or smooth flowstone Slide 23 Living
Organisms Lichens (plant-like organism) & roots of plants
produce weak acids Slowly dissolve rock around roots
trans_s_lichensndstn.jpg Stone colonized by lichens, which bit by
bit dissolve the rock into.morning-earth.org Slide 24 Acid Rain
Coal, oil, gas burned past 150yrs S, C & N compounds put in air
React chemically with water vapor in clouds Form acids Acids mix
with raindrops & fall as acid rain Causes very rapid chemical
weathering _Acid_rain_damaged_gargoyle_ .jpg Silverchair Acid Rain
lyrics lyricsdog.eu Slide 25 What is it? How fast weathering occurs
Rate of Weathering Slide 26 Most important factors determining how
fast weathering occurs: Type of Rock Climate Slide 27 Type of Rock
Minerals that make up rock determine how fast it weathers If
minerals dissolve slowly in water, rock weathers slowly. If
minerals dissolve quickly in water, rock weathers quickly.
Rocks.jpg edweb.tusd.k12.az.us Slide 28 Permeability What is
permeability?permeability Material is full of tiny connected air
spaces that allow water to seep through it. Some permeable rock may
weather more quickly Weathers chemically at faster rate because
water easily seeps into it, dissolves it & removes material
Slide 29 Climate climate refers to average weather conditions in
area Chemical and mechanical weathering occur faster in wet
climates Rainfall provides water needed for chemical changes &
physical changes (freezing and thawing) High temperatures -
Chemical reactions occur more quickly _ 470px ClimateMap_World.png
Slide 30 Rate of Weathering 278.Jpg water collects and accentuates
rates of chemical weathering uregina.ca Slide 31 Looking at the
SLOW process of weathering, how has the earth changed over time?
Give at least three examples and explain each. Is the earth still
changing through weathering? How do you know? Give at least three
examples and explain.
