Download CANADA`S LANDFORM REGIONS:

CANADA’S LANDFORM REGIONS:
• Landforms are the physical structures that make up the appearance
of the earth’s crust.
Some examples (but not all..) are: Mountains, Valleys, Plains, Hills….
• Think of landforms this way…
If you were a giant and could
pick the earth up, you would feel bumps, grooves, flat areas and
sharp areas….(hills, valleys, plains, mountains…..)
Landforms were created by different physical processes or processes,
some that build the land up or add new crust (volcanism), and some
that destroy the landforms by processes of erosion.
BUILDING THE LANDSCAPE:
• The three main forces responsible for mountain Building are
1) Folding
2) Faulting
3) Volcanism
FOLDING:
• When plates move, different kinds of pressure are emitted,
causing different effects to the physical land…
• The rock bends instead of breaking, creating folded layers.
• Some mountains are formed by the horizontal compression
(squeezing together) of rock layers as the continents come
together toward the middle —> ~~~ <—. This causes the rock
layers to buckle and fold (folding) : ie: Rocky Mountains.
FAULTING:
• Earthquakes at plate boundaries can create different landforms.
• Faulting is when the crust cracks (FAULTS) where two plates
(continents) meet.
• The plates could come together (make mountains) or move apart
(making valleys)
• Some mountains are formed by the rising and tilting of large
blocks of the earth’s crust (tilted or block mountains).
• Such movements occur along fractures in the earth’s crust called
faults.
•
This process is known as FAULTING…
• Or 2 fault lines squeezing a piece of crust in the middle causing
it to pop up (block Mountains)
VOLCANISM:
• Volcanoes generally occur along plate boundaries where magma
comes to the surface.
• Volcanoes add lava (rock) to existing landscape, eventually
creating a mountains.
EROSION: FORCES THAT DESTROY THE LANDSCAPE….
• Force that destroys the landscape (wear it down) are called
erosion
• Erosion is the physical breaking down of rock…
• this is done by 3 main forces
• WIND
• WATER
(think WWI so you don’t
forget it)
• ICE
WIND: Blows small pieces of rock or dirt around...
These pieces can hit other rock, further eroding it
(think sandblaster!!!)
WATER: Water in many forms breaks down the landscape
1. Rain
2.
Water falling (dripping and
waterfalls)
3 . Waves
ICE: Glacier and the Freeze Thaw Cycle
• When water freezes in a crack in the rock it expands….
• Freeze thaw cycles weekens the rock and eventually cause it to
crack and break off…
• (think about pot-holes on the road..)
•
Glaciers grind away the rock as the ice slides down the
mountain
CANADA’S LANDFORM REGIONS
What you need know about Canada’s landforms:
1. Canada has three basic types (shapes) of
landforms.
• #1 - The Canadian Shield (also called the Precambrian Shield)
• #2 - The surrounding series of plains or lowlands ( Prairie, St.
Lawrence Valley)
• #3 – The Highlands (Mountains)
Highland
Shield
Highland
2. They are not random
features; they form a pattern
that can be explained by the
processes or forces that
created them.
Lowlands
#1 - The Canadian Shield
•
It is the geologic core of the country. The shield (shaped like
a shield) used to be a mountain range that was 12 000 metres tall
that was eroded by glaciers millions of years ago.
• The eroded rock became the flat plains that surrounds the rounded
bump (all that is left of the original mountain)
•
ancient (4 billion years in some places), hard igneous rock from
which all the other areas were created
#2 – The lowlands
•
made of sedimentary rock
•
most of the sediments were eroded from the ancient Precambrian
Shield
•
includes the Great Lakes - St. Lawrence Lowlands, the Interior
Plains, the Hudson Bay Lowlands, and the Arctic Lowlands
•
#3 – The Highlands
also made up of, in part sediments from the ancient Shield, also with
metamorphic rock
•
•
•
•
•
the Appalachian Mountains (the oldest and hence the lowest due
to longer erosion)
the Innuitian Mountains of the very far north
the Western Cordillera (the youngest, and highest, is actually a
series of several different ranges dominated by the famous Rocky
Mountains, the most easterly of the Cordilleran ranges)
unlike the flat lowland areas, the mountains have been uplifted
by tectonic forces
there are three main mountain areas that make up the highlands
Canada
N
Physical Regions
Western Cordi l l era
Innui ti ans
Interi or Pl ai ns
Appal achi a
Canadi an Shi el d
Great Lakes St. Lawrence
Lowl ands
Lowl ands
Yukon
Yukon
Territory
Territory
Whi tehorse
Northwest
Territories
British
British
Columbia
Columbia
Alberta
Nunavut
Quebec
Manitoba
Alberta
Ontario