Forces that Shape Earth and Geological Time!

CGC1D- Canadian Geography

Planet Earth

1. Geologic History1. Cenozoic (66 mya – present)

2. Mesozoic (245 -66 mya) Dinosaurs

3. Paleozoic (570 -245 mya) Ancient Life

4. Precambrian (4600 -570 mya) Earliest Life

2. Landforms

3. Rock Cycle

Earth’s InteriorCrust/Asthenosphere- 8-64 km thick- cold & fragile-Granite and- BasaltMantle- 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

Geologic History

• Precambrian Era (Canadian Shield)

Vulcanism

Fault

Ancient SeaIgneous Rock

#1 - The Canadian (also called the Precambrian) Shield

• the geologic core of the country

• ancient (4 billion years in some places), hard igneous rock from which all the other areas were created

• used to be a huge mountain range

1. Precambrian Canada

Precambriam

• Extensive volcanic activity folding/faulting and erosion– Intrusive / extrusive igneous rock– Cooling, creates Canadian Shield – Foundation of Canada’s landmass– Heat/Pressure (metamorphism) creates storehouse of

Canada’s metallic mineral wealth– Surrounded by ancient sea

Geologic History

• Paleozoic Era (Shallow seas)

Igneous Rock

ErosionErosion

Sediments

Sediments

#2 - The surrounding series of plains or 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

Erosion

Deposition Deposition

TransportationTransportation

Paleozoic con’t

• Extensive erosion, transportation (rivers), deposition of sediments from the Shield into adjacent seas

• Compression of sediments in ancient seas create sedimentary rock

• Today these sedimentary rocks form the bedrock for parts of every province

• Organisms in seas form basis of oil/gas deposits in west• Swamps (tropical climate) create coal beds in east

Geologic History

• Late Paleozoic/ Early Mesozoic Era (Appalachians formed!)

Erosion

SedimentsSediments

Mountains Forming

Igneous Rock

Late Paleozoic, early Mesozoic!

• Creation of super-continent Pangaea folds/faults/uplifts Appalachian mountains in the east

• NA is very tropical!• Sediments keep on building up• Breakup of Pangaea as NA Plate moves West colliding

with the Pacific Plate

#3 - The mountainous rim

• also made up of, in part sediments from the ancient Shield, also with metamorphic rock

• unlike the flat lowland areas, the mountainous rim rocks have been uplifted by tectonic forces

• there are three main mountain areas that make up the mountainous rim

Finally, Cenozoic era creates today’s mountain ranges…

• 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)

Geologic History

• Cenozoic Era (last 65 million years!)

Mountains Forming

Igneous Rock

Sedimentary Mountains

Eroding

Sedimentary Plains

PACIFIC OCEAN ROCKY

MOUNTAINS INTERIOR PLAINS CANADIAN

SHIELD

APPALACHIAN MOUNTAINS

ATLANTIC OCEAN

1.

2.

3.

4.

Landforms not seen (in the back) - Hudson Bay Lowlands, - Arctic Lowlands, - Innuitian Mountains

Western Cordillera

Interior Plains

Canadian Shield

Great Lakes - St. Lawrence Lowlands

Appalachians

4. Cenozoic Canada

Plate Collision

3. Mesozoic Canada

Glaciers!!! – ended about 20 000 years ago

• Intrusive Volcanic / tectonic activity begin to uplift the Coastal Range

• Tectonic forces uplift the Rockies/and as the plate rotates NW the Innuitian Mountains. (Arctic)

• Dinosaurs roamed inland sea west of the Rockies (Red Deer Alberta) until extinction @ end of Mesosoic

• Cenozoic: Rockies/Coastal Mntns. continue to form• Volcanic Activity create plateaus between Rockies and

Coastal Ranges

Rock Cycle Videos

• http://www.youtube.com/watch?v=K8dDq3el_tQ&feature=related

• http://www.youtube.com/watch?v=EcfstbQyrzU

Rock Cycle

MAGMA

IGNEOUS

SEDIMENTARY

METAMORPHIC

Cools and hardens

Weathers, erodes, and deposits

Stresses or heats

Heats and melts