geography of canada planet earth. 1.geologic history 2.plate tectonics 3.continental drift...
TRANSCRIPT
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 – 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.
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