Plate Tectonics Key Question: What is plate tectonics and continental drift? Key Words: Plate Tectonics Continental Drift Sea Floor Spreading

From memory draw out the structure of the earth.

Characteristics of Plates C Continental Crust Oceanic Crust Upper Mantle Mantle Lithosphere Asthenosphere Fold Mountains Shield Areas Continental Shelf Continental Slope Abyssal Plain Root Zone Basaltic Granitic 2.7g/cm³ 3.0 g/cm³

Characteristics of Plates Fold Mountains Continental Slope Shield Areas Continental Shelf Abyssal Plain Sial Granitic Continental Crust Oceanic Crust 2.7g/cm³ Lithosphere Upper Mantle Basaltic 3.0 g/cm³ Sima Asthenosphere Root Zone Mantle

Use the images below to write a sentence to explain what continental drift is and who proposed it. Alfred Wegner Continental Drift is ………… It was proposed by………… 1915 In …………

1. Continental Fit Wegener, 1912 – idea of “continental drift” WEGNER’S EVIDENCE 1. Continental Fit Wegener, 1912 – idea of “continental drift” Supercontinent- Pangaea 200 mya Pangaea began to break up into Laurasia & Gondwanaland these continued to break up into smaller continents we recognise now

2. Biological Fossil remains of the freshwater reptile Mesosaurus Evidence for Plate Tectonics 2. Biological Fossil remains of the freshwater reptile Mesosaurus small reptile with limited swimming ability Fossil of fern Glossopteris large seeds fossil remains limited to freshwater areas fossil remains widely distributed associated with warmer climates

Evidence for Plate Tectonics 3. Geological

Evidence for Plate Tectonics 3. Geological

same trend, same age & rock types Evidence for Plate Tectonics terminate at present coastlines Appalachians, Scottish and Norwegian Mtns

Evidence for Plate Tectonics 4. Climatological Glacial till of same age in southern Africa, South America, India and Australia Coal deposits in Antarctica Permian Red Sandstone Beds in the British Isles – indicate deserts

Plate tectonics is ………… Plate Tectonic Theory Plate tectonics is ………… the ……………………………………. that the Earth’s surface layer (the ………………………………) is made up of ……. major plates and many minor plates which ………………… relative to one another on top of a mobile layer below known as the ……………………………. They meet at plate boundaries. Theory lithosphere 7 move asthenosphere The plates move by ………………… currents in the …………………………….. . convection Mantle

1. Continental Drift 2. Sea-floor Spreading 3. Plate Tectonic Theory History of Plate Tectonics 1. Continental Drift Wegener, 1912 – Biological, geological, climatological & continental fit Ewing, 1948 - Discovery & study of Mid-Atlantic Ridge 1950’s – Study of palaeomagnetism 2. Sea-floor Spreading Hess, 1962 – Age of rocks in Atlantic Ocean 1960’s - Discovery ocean trenches Alaskan earthquake, 1964 - Discovery of subduction zones 3. Plate Tectonic Theory J. Tizo Wilson – hotspot theory for Hawaii and work on conservative margins