Geography of Canada 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 Sea Igneous 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 Erosion Sediments

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 Sediments 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 OCEAN ROCKY 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

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 km thick - cold & fragile - Granite and Basalt Mantle km thick - hot & molten - Magnesium and Silicon Outer Core km thick °C - liquid Nickel and Iron Inner Core km thick °C - solid Nickel and Iron Air Land Water LITHOSPHERE HYDROSPHEREATMOSPHERE

Rock Cycle MAGMA IGNEOUS SEDIMENTARY METAMORPHIC Cools and hardens Weathers, erodes, and deposits Stresses or heats Heats and melts