Science 7

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Science 7

• Discovering Science 7
• Unit 4
• Earths Crust

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Chapter 10

• Earths Crust Is Made Up Off Rocks And Mineral.

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Minerals vs. Rocks

• Minerals
• A mineral is a pure substance
• ex. Gold
• Rocks
• A rock is a mixture of two or more minerals.
• ex. Granite

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Mineral/Rock Identification

• Lustre how light is reflected of the material
  (Dull, Glassy or metallic).
• Colour Spectrum of colour.
• Hardness Mohs Hardness Scale (1 softest ex.
  Talc and 10 hardest ex. Diamond).
• Streak Residue left after a rock is streak
  across porcelain (powder,)
• Cleavage Splitting along smooth, flat surfaces
  called planes. Ex. Mica
• Fracture Splitting along rough jagged edges.

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Families of Rocks

• Igneous, Sedimentary and Metamorphic

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Igneous Rock

• Intrusive Rock -
• Formed when molted rock (magma) cools under the
  surface of the earth.
• ex. Granite
• Extrusive Rock
• Formed when molted rock (lava) cools on the
  surface of the earth.
• ex. Obsidian

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Sedimentary Rock

• Formed when loose particles, weathered and eroded
  away, are compacted together. The extreme
  pressure and heat help cement the particles
  together.
• Cementation Process by which pieces of
  sediments are held together by another material.
• Layers of sediments form beds.

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Sedimentary Rock
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Metamorphic Rock

• Metamorphic means changed form.
• Formed when extreme pressure and heat, or hot
  fluid changes one type of rock into another.
• The formation of metamorphic rock is a slow
  process.
• Parent Rock - The type of rock which has been
  changed into metamorphic rock.

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Metamorphic Rock

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The Rock Cycle

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Many Things Are Made From Minerals and Rocks

• Zippers
• Watches
• Shirts
• Blood
• Muscles
• Shoes
• Detergents

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Mineral and Rock Resources

• Petroleum and Coal made from the remains of
  once living things.
• Metals Copper, Zinc, Nickel, iron,
• Gems Sapphires, Diamonds, emerald, Amethyst,

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Chapter 11

• Earths Crust Is Constantly Changing.

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The Layers of the Earth

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The Earths Moving Crust

• Alfred Wegener (1880-1930)
• Paleogeographic Evidence Shape of Continent
• - Pangaea
• - Theory of Continental Drift
• Biological Evidence Fossils
• Geological Evidence Rocks and Rock Layer
• Meteorological Evidence Climate Change

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Wegners Theory Rejected

• What caused the plates
• to move?
• Without an answer,
• some scientist rejected
• his theories.
• Today we accept the
• explanation of convection
• currents

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Evidence From The Sea Floor

• Sonar (Sound Waves)
• Magnetometers (Magnetic Fields)
• Deep Sea Drilling (Core Samples)

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Types of Plate Boundaries

• Divergent Boundaries
• Pulling apart
• Convergent Boundaries
• Pushing together
• Transform Boundaries
• Sliding past (J. Tuzo Wilson)

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Convection Currents

• The driving force that possible causes plates
  tectonics (movement of the earths crust).
• The creation of subduction zones The area of
  the crust when one plate is push below another
  plate.

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Earths Crust Catastrophes

• Earthquakes
• - Seismograph (Seismic Waves)
• - Bedrock
• - Richter Scale
• - Focus and Epicentre
• Volcanoes
• Occur
• - areas where plates converge
• - areas where plates diverge
• - areas where plates are thin (hotspots)

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Mountain Building

• Fold Mountains
• Fault Block Mountains
• Volcanic Eruption

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The Geological Time Scale

• The Fossil Record The Origin of Man
• Evolution vs. Creation
• Precambrian formation of the Earth and
  appearance of simple life forms.
• Paleozoic appearance of more complex life forms
  .
• Mesozoic appearance and extinction of
  dinosaurs.
• Cenozoic appearance of humans.

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Chapter 12

• Soil Is The Living Component Of Earths Crust.

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Weathering

• Weathering is the mechanical and/or chemical
  breakdown of rocks.
• Chemical
• - Acid rain and ground water
• -Acid actions of organism (animals and plants)
• Mechanical
• Ice/Frost Wedging
• Plant roots Wedging
• Animal Factor pathways, burrow,

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Erosion

• Erosion is the process that loosens and moves
  weathered rock particles over the earths
  surface.
• Water in motion
• Meteorological processes (rain and wind)
• Geological processes (gravity and glaciers)

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Classifying Soil

• Soil is a combination of eroded rocks and
  minerals, water, air, and organic
  material.
• Humas is material made from breaking down plant
  And animal remains.
• Texture relates to how soil feels when robbed
  between fingers.
• - Coarse-textured (sandy, gravel).
• - Medium-textured (loamy).
• - ?ne-textured (clay).

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Porosity and Permeability

• Porosity
• The amount of empty space in soil or a rock.
• Permeability
• The measure of how easily liquids and gases pass
  through a soil or a rock

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