Transcript THE EARTH`S CRUST

THE EARTH’S CRUST
Notes for Test
LAYERS OF THE EARTH
• Inner Core: Hottest but a solid due to all the
pressure.
• Outer Core: Second hottest, liquid metal, second
biggest.
• Mantle: Biggest, partly solid, partly liquid.
• Crust: Thinnest layer, solid, coldest layer, only layer
with life on it.
• Be able to label a diagram showing the four
different layers inside of Earth
Rocks and Minerals:
• Minerals are pure substances
and all minerals are crystals.
(halite which is salt, talc, quartz,
diamond, mica, jade…) Minerals
are the building blocks of rocks.
• Rocks are combinations of
different minerals (granite,
limestone have different
minerals in the same rock).
• pp 198-199
• Know the difference between
rocks and minerals
IDENTIFYING MINERALS
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There are many different minerals and many characteristics that help
identify them:
Streak: uses a streak plate
Lustre: how it appears to reflect light
Hardness: Mohs Scale
Cleavage: how it breaks..how many flat edges
Magnetic: Will it attract to a magnet
Colour: What colour is the mineral?
Taste:
p 199
Be able to identify how to perform a test for each and how it helps to
identify the mineral tested
Look at Working with Our Specimens sheet too
MINING
In order to get valuable minerals we must mine (dig out) and process the ore
(separate from rock to extract the mineral).
 Ore is rock that contains valuable mineral.
 A deposit is a place that has ore in it.
The type of mining used depends on where the mineral is found.
Review the activity Explore an Issue, Mining for Minerals pp 204-205
Sedimentary Rock: water carries weathered rock (sediment) downstream
where it settles and turns into layered rock from pressure. e.g.
sandstone
Fossils are usually found in sedimentary rock.
WEATHERING AND EROSION
Weathering is the breaking down of rock.
Weathering can happen through:
BIOLOGICAL: done by living
things (plants, animals).
MECHANICAL: done by physical
force (water, wind, ice).
CHEMICAL: due to a rocks reactions
with another substance (acid rain,
dissolving).
Erosion is the movement of broken down rock and mineral to a new location
Review Glaciers in Maritime Canada Sheet: Look at part about glacial
movement, Straie and how there can be more than one groove/scratch on a
rock caused by glaciers.
SOIL HORIZONS
• LITTER: the surface of the soil is usually
covered with leaves, broken branches
and fallen trees called litter. Litter keeps
the soil damp.
• TOPSOIL: usually contains dark, decaying
plant and animal matter called humus
that provides nutrients for plants.
• SUBSOIL: contains larger pieces of rock
and clay. Usually a lighter colour because
it contains less humus.
• BEDROCK: a layer of solid, unbroken rock
that is subject to biological weathering
and over time can become part of the
subsoil.
• Review soil horizons sheet that you
coloured and passed in.
SOIL
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HUMUS: decaying plant or animal matter that provides nutrients for plants.
SAND: biggest particles, biggest spaces
SILT: medium particles, medium spaces
CLAY: smallest particles, smallest spaces
SPACES IN SOIL
Spaces in soil provide room for air and water.
• AIR: allows room for roots to grow and air for decomposers to live
and break down plant and animal matter.
• WATER: gives life to plants and decomposers.
ENRICHING the SOIL
• Adding substances to soil to improve it’s quality (fertilizers).
Many changes in lakes and other water systems have happened
because of fertilizer runoff from fields.
• When farmers plant and harvest the same crops year after year
(monoculture) the nutrients from the harvest don’t get a chance
to decompose and return to the soil. Therefore the soil will lose
nutrients over time.
• Review case study 4.10 Why is monoculture harmful to the soil,
what do different plants in the same field and/or crop rotation
keep the soil healthy.
• Often farmers use crop diversity within a single field and/or crop
rotation (changing crop from year to year) to avoid this problem.
Continental Drift
• Plate tectonics review Continental Drift Activity
Packet and map of Pangaea
• Moving plates p228-229 Slipping Fault, Colliding
Plates (Subduction and Uplift), Separating
Plates
Review Questions
• The following questions may be useful to
look at for your review.
• pp 246-249 1,2,4,10,12,19,25,26,31,33