Geography of Canada

Planet Earth

Planet Earth

1. Geologic History

2. Plate Tectonics

3. Continental Drift

4. Earth’s Interior

5. Rock Cycle

Geologic History

• Precambrian Era• 4.6 billion years ago – 570 million

years ago.

-Appearance of single / multi-cell organisms

Creation of the Canadian Shield.

Vulcanism

Fault

Ancient SeaIgneous Rock

Geologic History

• Paleozoic Era – 570 million years ago – 250 million years ago.

• Sedimentary Rock formed bedrock of all provinces.

• Early plants and amphibians, sea life and insects.

Igneous Rock

ErosionErosion

SedimentsSediments

Geologic History

• Mesozoic Era – 250 million years ago – 66 million years ago.

• Formation of Rocky and Coastal Mountains.

• Inhabited by dinosaurs, plant life forms and reptiles.

Erosion

SedimentsSediments

Mountains Forming

Igneous Rock

Geologic History

• Cenozoic Era – 66 million years ago – present day

• Extinction of dinosaurs, human era (2 million years ago)

• Canada’s landforms take present shape, ice ages.

Mountains Forming

Igneous Rock

Sedimentary Mountains Eroding

Sedimentary Plains

PACIFIC OCEANROCKY MOUNTAINS

INTERIOR PLAINS

CANADIAN SHIELD

APPALACHIAN MOUNTAINS

ATLANTIC OCEAN

Plate Tectonics

• The Earth’s crust is divided into 12 major plates (both continental and oceanic plates).

• Heat from deep inside the earth causes plates to move, like crackers floating in a bowl of soup.

• Earth’s continents sit on plates, so when the plates move, the continents move with them

Plate Tectonics cntd.

• On average, the plates move about as fast as fingernails grow…an inch or so every year

Plate Tectonics Cntd.

• When plates move, they can:• They can collide, pull apart, or scrape against

each other which can create mountains, volcanoes or earthquakes.

Plate Tectonics Map

Plate Tectonics - Continental Drift

Plate Tectonics - Continental Drift

Plate Tectonics - Continental Drift

Antarctica

THE CONTINENTS TODAY

Plate Tectonics – Continental Drift

• In 1912, Alfred Wegener put forward a paper expressing his belief that the earth’s continents were moving (however, very slowly).

• His reasoning?

1) The fit of the continents

2) Fossil Evidence

3) Rock-type similarities

4) Evidence of Glaciers in Warm Climates• In 1968, John Tuzo Wilson, a Canadian

geophysicistproposed that “convection currents” in the earth’s “mantle” provided adequate energy to displace landmasses.

Plate Tectonics - Continental Drift

PROOF!

Earth’s Interior

Crust- 8-64 km thick- cold & fragile- Granite and Basalt

Mantle- 1800 km thick- hot & molten- Magnesium and Silicon

Outer Core- 2000 km thick- 3 - 4000°C- liquid Nickel and Iron

Inner Core- 1400 km thick- 5 - 6000°C- solid Nickel and Iron

Air

Land

Water

LITHOSPHERE

HYDROSPHERE ATMOSPHERE

Rock Cycle

MAGMA

IGNEOUS

SEDIMENTARY

METAMORPHIC

Cools and hardens

Weathers, erodes, and deposits

Stresses or heats

Heats and melts