Name:
Date:
Day/Period:
CGC 1D1 Unit 2: Interactions in the Physical Environment
Landform Regions
!
PART A: Linking to Tectonics
!
The movement of the earth’s plates, and the resulting folding, faulting, and
volcanic activity, have combined with the forces of weathering and erosion to
create a variety of landscapes that affect the way we live.
!
Landforms are the physical structures that make up the appearance of the
earth’s crust. Landforms were created by different physical processes, some
that build the land up or add new crust, and some that tear (destroy) the land
down by processes of erosion.
!
Building the Land
!
!
!
!
!
!
!
!
!
!
!
Review: !
Land Erosion
• Over millions of years, Canada’s physical landscape has changed; 300
million years ago, the super continent of Pangea existed; 200 million
years ago the continents drifted apart creating their modern locations
• At times, continents collided and pushed the crust up to create mountains
(Himalayas)
• At other times, earthquakes happened where one piece of land shifted and
rose up
• Volcanoes also erupted along fault lines to create volcanic mountains.
Building Landscape
Main forces responsible for land building:
1) Folding
2) Faulting
3) Volcanism
!
Forces That Destroy Landscape
1) Erosion
2) Weathering
Part B: Building the Landscape
!
Folding
• When plates move, different kinds of pressure are emitted, causing
different effects to the physical land.
• Some mountains are formed by horizontal compression (squeezing
together) of rock layers as continents come together causing the rock
layers to buckle and fold.
!
See how one plate
(right side) is folding
because two plates
are colliding.
!
!
!
!
!
!
!
!
Faulting
• Again, earthquakes at plate boundaries can create different landforms
• Faulting occurs when the crust cracks where two plates meet.
• Some mountains are formed by the rising and tilting of large blocks of
the earth’s crust; can cause land to pop up creating mountain OR can
create valleys (tilted or block mountains)
Volcanism
• Volcanoes add lava (rock) to existing landscape, eventually creating
mountains
!
Here, cooling lava
from a submarine
eruption creates
land which
emerges from the
ocean as a new
island.
!
!
Part C: Forces that Destroy the Landscape !
Erosion and Weathering
• Weathering is what breaks the rock into smaller pieces.
• Erosion is the actual removal of the rock pieces (think of wiping dirt off a
table)
• There are 3 main forces of weathering/erosion:
!
Wind
!
!
!
!
!
! Blows small pieces of
! rock or dirt around;
! these pieces can hit
! other rock, further
it (think
! eroding
sandblaster!!!)
!
!
!
!
!
!
!
!
!
!
!
Water
Water in many forms breaks
down the landscape.
• Rain
• Water falling (dripping and
waterfalls)
• Waves
Ice
!
!
!
!
When water freezes & turns
into ice, it expands almost
10%. (Think about a can of
pop that explodes in the
freezer.)
!
Nature’s Freeze/Thaw
Cycle: When water freezes
in a crack in the rock it
expands; the cycle weakens
the rock and eventually
causes it to crack and break
off (think about pot-holes on
the road)