Transcript Slide 1
Forces that Shape Earth and Geological Time! CGC1D- Canadian Geography Planet Earth 1. Geologic History 1. 2. 3. 4. Cenozoic (66 mya – present) Mesozoic (245 -66 mya) Dinosaurs Paleozoic (570 -245 mya) Ancient Life Precambrian (4600 -570 mya) Earliest Life 2. Landforms 3. Rock Cycle Earth’s Interior Crust/Asthenosph ere - 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 HYDROSPHERE Air Water ATMOSPHERE Land LITHOSPHERE Geologic History • Precambrian Era (Canadian Shield) Vulcanism Fault Ancient Sea Igneous Rock 1. Precambrian Canada #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 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) Erosion Erosion Sediments Igneous Rock Sediment s #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 Transportation Deposition Erosion Transportation Deposition 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 Sediments Sediments Igneous Rock Mountains Forming 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 Finally, Cenozoic era creates today’s mountain ranges… #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 • 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!) Sedimentary Mountains Eroding 4. 2. PACIFIC OCEAN Mountains Sedimentary Forming Plains ROCKY MOUNTAINS INTERIOR PLAINS 1. Igneous Rock CANADIAN SHIELD APPALACHIAN MOUNTAINS ATLANTIC 3. OCEAN 3. Mesozoic Canada Plate Collision 4. Cenozoic Canada Western Cordillera Appalachians GlaciersCanadian !!! – ended about 20 000 years ago Shield Interior Plains Great Lakes St. Lawrence Lowlands Landforms not seen (in the back) - Hudson Bay Lowlands, - Arctic Lowlands, - Innuitian Mountains • 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=K8dDq3 el_tQ&feature=related • http://www.youtube.com/watch?v=EcfstbQ yrzU Rock Cycle MAGMA Heats and melts Cools and hardens IGNEOUS METAMORPHIC Stresses or heats SEDIMENTARY Weathers, erodes, and deposits