Plate Techtonics Unit 2 – Physical Connections
Video introduction The Early Earth and Plate Tectonics: =com.microsoft:en- US&resnum=0&q=plate%20tectonics&um=1& ie=UTF-8&sa=N&tab=wv#
Continental Drift Think of a frozen lake –Thin layer of moving plates –Material that is constantly in motion Movement of these plates causes earthquakes
The supercontinent of Pangaea In 1915, Alfred Wegener, a German scientist, stated that 300 million years ago all of earth’s land masses, which are constantly in motion collided to form one supercontinent. He called it Pangaea –Which continents used to fit together and where? –What proof did Wegener have? P 91
Pangaea – 300 million years ago
Plate tectonics 1968 J. Tuzo Wilson, a Canadian, helped spark interest in Plate Tectonics –New technology –20 Plates made up of both ocean and continent –They move over a weak layer of hot rock, which flows like slow moving plastic –It is thought that an unequal distribution of heat causes convection currents to move these plates.
Plate tectonics continued The movement of the plates shapes the world: –In Canada: The Rocky Mountains, the Appalachian Mountains –The World: The Alps, The Andes
Homework Page 89 Questions 1-4 Page 94 Questions
Geologic Time Cenozoic Mesozoic Paleozoic Precambrian
Cenozoic (recent life) 66 million years to present –Ice sheets cover much of the earth –Continents take on their present shape –Formation of the Rocky Mountains Biological Events –Human beings develop –Age of mammals –Modern forms of life evolve
Mesozoic (middle life) 245 million to 66 million years –Shallow seas in the interior of North America Biological Events –Age of reptiles, such as dinosaurs –First flowering plants –First birds and mammals
Paleozoic (ancient life) 570 – 245 million years –Appalachians formed –Periods when large parts of North America are covered by shallow seas. –Age of amphibians and fish –First insects –Large swamps-coal formed from this vegetation –First plants and animals appear on land
Precambrian (earliest Life) 4.6 Billion years ago – 570 million years –Rock shield formations: Canadian Shield, Brazilian Shield, African Shield and the Australian Shield. Biological Events –First single and multi-celled organisms
The Task Create a graphical representation of the four eras showing information from the preceding slides and the Text book on pages