Plate Tectonics July 29, 2019

Pangaea Wegener and the theory of Continental drift – that the continents were once together in a “supercontinent” called Pangaea Evidence: Fossil correlation Glacial evidence in lower latitudes and tropical deposits in higher latitude regions Controversial theory not accepted by most scientists Wegener could not come up with a way to explain how the continents moved

Layers of the Earth The Earth’s plates are made up of a layer that includes the upper mantle and the crust. This layer is called the lithosphere.

The Earth’s Plates The Earth’s lithosphere is made of 7 major plates and several smaller ones

Plate Boundaries Divergent Convergent Transform Two plate move apart Two plates move together Transform Two plates slide past each other

Divergent Boundary Seafloor spreading and rifting – Ex: Iceland and Africa

Convergent Boundary The “Ring of Fire” around the Pacific plate Subduction: Oceanic plate sinks under continental plate Himalayas and Mt Everest Indian plate is colliding with the Eurasian plate

Transform Boundary San Andreas fault – the western part of central and southern California is moving north relative to the rest of California Video

Hotspots Hawaii – the Pacific plate is moving across a fixed zone of hot magma

Questions WRITE OUT ALL QUESTIONS AND ANSWERS : Pg 253 #1-4