Download Sedimentary Rock

Inner Structure
Crust:
Mantle:
•Mostly liquid
•Solid
•3,000km thick
•5-40km thick
•1,000 to 3,700 0C
•Up to 1,0000C
•Magnesium, Iron,
Aluminum, Silicon
•Mostly igneous
rock
Outer Core:
•Liquid
Inner Core:
•3,000km thick
•Solid
•3,700 to 4,3000C
•1,500km thick
•Nickel-Iron alloy
•4,3000C
•Mostly Iron
Asthenosphere:
upper mantle
http://www.geography.learnontheinternet.co.uk/topics/structureofearth.html
•Responsible for
controlling Earth’s
magnetic field
Inner Structure
•Lithosphere: the rigid part of
the crust and upper mantle
that forms the plates and is
made up of rocks. The three
main types of rocks are
Sedimentary, Metamorphic and
Igneous. Minerals are the
building blocks of rocks.
•Asthenosphere: upper mantle
that flows but is not a true
liquid. Causes the plates to
move.
•Mesosphere: makes up rest of
mantle.
•Oceanic crust is very dense.
•Continental crust is less dense.
Sedimentary Rocks
•Sedimentary rocks are formed when layers of sediment are
deposited at the bottom of seas and lakes.
•Over millions of years, the layers underneath become squashed by
the layers on top.
•The water is squeezed out of the bottom layers so that the layers
become cemented together.
•Examples of sedimentary rock include:
•Sandstone – hardened sand
•Mudstone – hardened mud
•Shale – hardened mud
•Conglomerate – pebbles and other debris cemented together
•Limestone – made from lime (calcium carbonate) deposits from
shells. Stalagmites and stalactites found in caves are limestone.
Sedimentary Rock &
•Fossil fuels such as coal, oil and natural gas are formed in
sedimentary rock.
•Hundreds of millions of years ago the dead organisms bodies became
trapped in the sedimentary layers.
•When the layers became deep enough, the intense heat and pressure
caused chemical reactions in the dead organic matter and turned it
into hydrocarbons.
•Humans have learnt to extract these fossil fuels from deep within
the Earth and burn them in order to provide energy.
http://www.energyquest.ca.gov/story/chapter
08.html
http://members.macconnect.com/users/d/dansy
monds/My%20Army%20Life.html
http://www.nicorinc.com/en_us/commercial/product
s_and_services/natural_gas_cooking.htm
Metamorphic Rocks
•Metamorphic rock is formed as sedimentary rock is pushed deeper
into the Earth’s surface.
•Here it is heated due to the pressure from rocks layered above it
and the surrounding temperatures in the mantle.
•The temperature changes the chemical composition of the rock.
•Sedimentary shale becomes metamorphic slate.
•Sedimentary limestone becomes marble which is a very hard material
and has many uses in our everyday lives.
Igneous Rocks
•Igneous rocks are formed when molten rock (magma if it is below
the surface and lava if it is above the surface) solidifies.
•Igneous rock has crystals in it. The crystals are small if the rock
has cooled quickly and large if the rock has cooled slowly.
•Examples include:
•Granite
•Pumice
•Basalt
Weathering & Erosion
•Weathering is the process of breaking
down rocks.
•This can either be physical weathering or
chemical weathering.
•Physical Weathering just breaks down
the rocks into smaller pieces without
altering the chemical structure.
•Chemical weathering breaks down the
rocks by chemical reactions forming new
compounds
•Erosion is the movement of weathered
particles from one place to another.
Kimberley Region north Western Australia
Agents of Weathering and Erosion
Surfers Paradise, Queensland
Agents of Weathering
• Wind
• Waves
• Running Water
• Extremes of heat
and cold
• Acid
• Tree roots
Sometimes the agents
cause weathering
and erosion at the same
time
Agents of Erosion
• Wind
• Waves
• Running Water
• Glaciers
Wind
Bondi Cliffs
Kimberley Region north Western Australia
The wind picks up sand particles acting like
sand paper, weathering and eroding the rocks
Waves
The Gap, Sydney
The Great Australian Bight South Australia
The energy of the waves causes parts of the cliff to
be broken off and then the waves wash the weathered
material away. The cliffs are both weathered and
eroded by the waves
Waves
The 12 Apostles Southern Coastline of Victoria
All of these rocks were once part of the mainland and the
energy of the waves has weathered and eroded the rocks
producing the 12 Apostles, caves and beaches.
Running Water
Mungo National Park south west of NSW, near the Victorian border
The rain weathers and erodes the rocks to
form the patterns shown.
Running Water
Small waterfall in the Kimberly Region in north Western Australia
Running water causes both the wearing away of
rocks, making them very rounded and smooth
and the erosion of the worn away pieces
Running Water
The rain dissolves
chemicals in the
rock causing
chemical
weathering and
erosion of the
material and
producing vertical
cracks.
Chemical Weathering
Jenolan Caves NSW
Running water dissolves calcium compounds in the
rocks which are then washed away leaving large
caves.
As the water evaporates from droplets stalagmites
and stalactites form.
Acid & Tree Roots
Physical Weathering: The roots growing in the cracks
cause the cracks to become larger until eventually
pieces of rock break off.
Chemical Weathering: The acid produced by the roots
chemically breaks down the surrounding rock.
Different types of rocks weather
and erode at different rates
“China Wall” in the
Kimberley Region.
The “wall” left standing is
a quartz outcrop
Ayres Rock or Uluru, central
Australia
Weathering and erosion
caused this huge rock to
become exposed and stand
above its surroundings.
State the agents of weathering &
erosion for A & B
A. Rocks between Bondi & Bronte
B. Rocks along a river in the Kimberley
Region in north Western Australia
State the agents of weathering &
erosion for C & D
C. Kimberly Region north
West Australia
D. Kimberly Region north
West Australia
State the agents of weathering &
erosion for E & F
E
The Bungle Bungles in the Kimberly Region
F
Stopping Erosion
Plants in the sand or soil stop the sand
or soil from being washed or blown away
and therefore stop the erosion
Deposition
Small particles
eroded
upstream are
deposited on
the slow bend
of the river and
as small islands
in the center
shallows.
http://www.kented.org.uk/ngfl/rivers/River%20Articles/braiding.htm
Percentage and Role of
Gases in dry Air
Percent of gases in the air we breathe
Oxygen 21%
Nitrogen 78%
Carbon Dioxide & Argon 1%
•Oxygen is used by organisms to make energy during cellular
respiration.
•Carbon dioxide is used by plants when photosynthesizing.
•Nitrogen is ‘fixed’ from the atmosphere by bacteria in the soil so
that plants can use it.
Role of other atmospheric
Gases – Ozone depletion
1.
CFC’s released
4.
Cl destroys ozone
2.
CFC’s rise into ozone layer
5.
Depleted ozone produces more UV
3.
UV releases Cl from CFCs
6.
More UV leads to more skin cancer
http://www.epa.gov/ozone/science/process.html
Role of other atmospheric
Gases – Ozone depletion
Role of other atmospheric
Gases – Green House Gases
•Greenhouses gases include: Carbon Dioxide (C02), Methane (CH4), CFCs, Water Vapour
(H2O), Nitrous Oxide (N2O).
•The shorter wave length visible light comes in to the atmosphere from the sun hits the
Earth’s surface and is released as heat, or infrared radiation.
•The infrared radiation is mostly absorbed by the greenhouse gases in the atmosphere
and so becomes ‘trapped’ around the Earth and cannot escape.
•Without the greenhouse effect the Earth’s temperature would be much cooler.
http://www.press.uillinois.edu/epub/books/brown/ch9.html
Atmosphere vs. Space
http://starryskies.com/solar_system/Earth/atmosphere.html
References
•Internet Geography [not date] Retrieved form the site: http://www.geography.learnontheinternet.co.uk/topics/structureofearth.html
September 2004.
•Miles, K. & Peters, C. (1997) Earth’s Atmosphere. Retrieved from the site: http://starryskies.com/solar_system/Earth/atmosphere.html
September 2004
•Ritter, M. (2003) The Physical Environment. Retrieved from the site:
http://www.uwsp.edu/geo/faculty/ritter/glossary/l_n/lithosphere.html September 2004.
•http://www-class.unl.edu/geol109/earthstructure.htm ddd
•Moorland School Clitheroe [no date] Earth Science - The Rock Cycle. Retrieved from the site:
http://www.moorlandschool.co.uk/earth/rockcycle.htm September 2004.
•United States Environment protection Agency (2004) The Process of Ozone Depletion. Retrieved from the site:
http://www.epa.gov/ozone/science/process.html October 2004.
•University of Illinois (2003) Global Warming. Retrieved from the site: http://www.press.uillinois.edu/epub/books/brown/ch9.html
October 2004.