| 
			 | 
				
					| Plate Tectonics |  
					| Lecture 12 3/4/98
 |  
 
				
					| |  | On Monday, we discussed mass extinctions and some of the causes behind them | 
 |  | Today, we will look at an earth process that could be the driving force behind many mass extionction | 
 |  | Plate Tectonics, is a unifying theory in geology that helps explain many of the changes that we see in the earths history. | 
 |  | Plate Tectonics is geology's theory of evolution. | 
 |  | It is a unifying theory that allows explanation of many geologic processes | 
 |  | Plate Tectonics has revolutionized the way that we view the earth | 
 |  | The earth's surface is dyamic not static | 
 |  | The "fit" of the continents. | 
 |  | Devonian Old Red Sandstone in England | 
 |  | similar in age and appearence to rocks on N. America | 
 |  | Features of the ocean floor | 
 |  | Seafloor Spreading and Plate tectonics | 
 | Plate Tectonics and Extinctions | 
 |  | openning and closing oceans | 
 
						 |  |