Chapter 8 Worksheets Section 1-4

8-1 After You Read: Complete the table by describing evidence that has been used to support the continental drift hypothesis and the theory of plate tectonics. Hypothesis or Theory Supporting Evidence Continental drift hypothesis Theory of plate tectonics Similarities in shapes of the continents; same fossils and distinctive rock formations found in South America and Africa; climate change evidence. Location of earthquakes and volcanoes; magnetism of ocean floor; age of ocean floor.

8-2 Complete the graphic organizers to explain the processes that take place at a subduction boundary and a divergent boundary. Molten rock rifts or cracks Oceanic continental Molten rock Deep-sea trench Deep-sea trench Volcanic islands Mountain chain Moves away

Cause of plate movement 8-3 After You Read Complete the table by listing three hypothetical causes for plate movements. Identify the type of boundary associated with each. Put a plus or minus sign next to the factors most or least influential on plate movement. Cause of plate movement Type of boundary 1. Mantle convection Divergent boundary 2. Slab pull 3. Ridge push Subduction boundary

8-4 After You Read Mountain ranges far from plate boundaries today. Data about ages of rocks. Fossils Evidence of glaciers in lands that are now tropical.

8-4 After You Read Deep-sea sediments Igneous rock River sediment Terranes