Earths interior layers'

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Earths interior layers.

• The major layers of the Earth consist of the
  crust, mantle, outer core and inner core.

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INNER CORE

• The core is composed mainly of iron and nickel.
  In the inner core, iron and nickel are
  solid.Although the inner core is very hot,
  pressure from the weight of the rest of the Earth
  doesnt allowed the material to melt. Irons
  normal temperature of melting is 15350C, but in
  the earth inner core it could stand 40000C with
  no melting.

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OUTER CORE.

• Because less weight is exerted on the outer core,
  the pressure is less there, so iron and nickel
  present here in liquid state.
• The molten outer core flows at the very slow rate
  which means electrons from the metals produce an
  electrical current.
• This electrical current powers the earths
  magnetic field.

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THE MANTLE

• The mantle is composed of hot iron-rich silicate
  rocks.
• Flow in the mantle occurs as convection currents
  hot material in the mantle rises, cools and then
  sinks.
• Mantle is elastic which means it behave in
  plastic manner.

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THE CRUSTAL SURFACE.

• CONTINENTAL CRUST
• is between 20 and 60 km thick. It is
  composed of granitic rocks, which are less dense
  than basaltic rocks of the oceanic crust. So,
  most of continental crust is above sea level.
• OCEANIC CRUST -
• is only about 10 km thick. It is composed of
  basaltic rocks, which are more dense than
  granitic rocks of the continental crust. So,
  oceanic crust is below sea level.

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Composition of the Earth.
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THE THEORY OF PLATE TECTONICS

• The framework explains how and why the surface of
  the earth constantly changes is called theory of
  plate tectonic.
• The theory states that the earths outer shell,
  the lithosphere is divided into eight large
  plates.
• Because each plate moves as a single unit, the
  interiors of the plates are generally stable. All
  major activity such as earthquake or volcano
  occur along the plate boundaries.

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DIFFERENT TYPE OF BONDARIES

• DIVERGENT PLATE BOUNDARIES- plates are moving
  away from each other. Very active volcanically
  due to the rising of magma.
  (Mid-Atlantic Ridge)
• CONVERGENT PLATE BONDARIES- plates are coming
  together. The regions of plate collision are
  regions of great mounting buildings.
• (Andes, Himalayas, Sierra Nevada)

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• Oceanic Oceanic Convergence
• Collision between two oceanic plates can
  result in the prosses when one plate bends and
  descends beneath the other to produce deep
  oceanic trench. (Marianas Trench)
• Oceanic Continental Convergence
• When an oceanic plate and a continental
  plate converge, the denser oceanic plate is
  subducted beneath the less dense continental
  plate.A deep ocean trench is formed and magma is
  generated. (Andes)
• Continental Continental Convergence.
• The collision between continental plates
  has produced some of the most famous mountain
  ranges. (Himalayas, European Alps, Appalachian)

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ROCKS AND MINERALS

• MINERALS are the building blocks of rocks, and
  elements, in turn, are the building blocks of
  minerals.
• A mineral is defined as a naturally formed,
  inorganic, crystalline solid, composed of an
  ordered arrangement of atoms with specific
  chemical composition.
• Of the known 112 elements, 92 occur naturally in
  the earths crust and combine to make 4000
  different minerals.

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ROCK TYPES

• IGNEOUS ROCKS are formed by the cooling and
  crystallization of hot, molten rock magma. The
  word igneous means formed by fire. Igneous
  rocks make up about 95 of the Earth crust.
  Basalt and granite are common igneous rocks.
• SEDIMENTARY ROCKS are formed from pieces of other
  rocks (sediments) carried by water, wind, or ice.
  Sedimentary rocks are easy to find on the ground
  beneath our feet the uppermost portion of Earth
  crust. Sedimentary rocks cover more than
  two-thirds of the Earths surface. Sandstone,
  shale, and limestone are common sedimentary
  rocks.
• METAMORPHIC ROCKS are formed from older,
  preexisting rocks (igneous, sedimentary, or
  metamorphic) that are transformed by high
  temperature, high pressure, or both without
  melting. The word metamorphic means changed in
  form. Marble and slate are common metamorphic
  rocks.

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ROCK CYCLE
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MINERALS
Silicates
Nonsilicates
Carbonates
Sulfates
Clay Minerals
Sulfides
Oxides
Ferromagnesian
Halides
Phosphates
Nonferromagnesians
Native Elements