Name: __________________________ Date: ___________________________ Geology 101: Plate Tectonics Introduction: Plate tectonics is the widely accepted scientific theory of large-scale movements and deformation of the Earth's lithosphere (the crust and upper mantle). All of the continents and ocean floor that we see today sit upon rigid plates that are independent of one another. These plates can contact each other in several different ways. This contact forms boundary zones at the edges of the plates and can be classified as such: convergent boundaries, divergent boundaries and transform boundaries. The implication is that the continents have not always been in the position that they are in today. They have been constantly moving across the surface of the earth. In fact, once upon a time, (200 – 300 million years ago) the continents came together to form one super-continent named Pangea and a global sea named Panthalassa. The formation and subsequent breakup of this super continent occurred because of tectonic processes. Objective: This lab's objective is to define the three types of plate tectonic boundaries, how they interact with each other and how they affect, create and alter the geology that surrounds them both above and below the surface. Also this lab is intended to make a student familiar with a Plate Tectonic World Map and to define tectonic hot spots. Part I. Types of Plate Boundaries There are three types of boundaries associated with plate tectonics. Please go to this website: http://pubs.usgs.gov/publications/text/understanding.html and read about these boundaries in order to answer the questions below. 1. What are the three types of tectonic plate boundaries? 2. What directions do the plates move relative to one another in a divergent plate boundary? 3. What is a spreading center and what is created at one? 4. Name one spreading center (or divergent plate boundary). 5. What are the three types of convergent plate boundaries? 6. Describe the crustal interactions at subduction zones—naming the crustal types involved. 7. What type of convergent boundary formed the Himalaya Mountains? 8. What happens along a transform plate boundary? 9. Name the famous transform fault in the western United States. 10. Which plates are sliding past each other along this fault? (from question 9) Part II. Tectonic Boundary Interactions Now please go to this website: http://www.pbs.org/wgbh/aso/tryit/tectonics/ and click on “Go directly to Plate Tectonics Activity.” 11. Drag each of the arrows in the activity to see the plat interactions. List, from left to right, each types of plate boundary shown in the activity. Now, go to http://emvc.geol.ucsb.edu/forteachers/flashmovies/Spreading.swf Wait a few seconds for it to load a movie. 12. What is happening to the plates at the red line in the center of the screen? Now go to http://emvc.geol.ucsb.edu/forteachers/convergence.htm and click on the picture labeled “Subduction.” Wait for it to load another movie. 13. What two kinds of convergence are shown in the movie? Part III. Tectonic Maps and Hot Spots For this next section please go to http://emvc.geol.ucsb.edu/forteachers/flashmovies/Pangea.swf and watch the continent Pangea break up. This animation shows how the continents looked around 150-200 million years ago when they were all part of the super-continent Pangea and the subsequent breakup to the familiar continental placement we see today. 14. During the time of Pangea, what continents were in direct contact with North America? 15. Referring to the map, what plates are in contact with the Pacific Ocean? 16. What is the Ring of Fire and what type of plate interaction is responsible for its formation? The Hawaiian Islands are known as a volcanic island chain. Each island has formed in succession of its predecessor however it occurs in the center of the Pacific Plate where no contact between another plate occurs. (For a visualization go to: http://education.sdsc.edu/optiputer/flash/hotSpots.htm.) In this lab, we have seen volcanic islands form at divergent plate boundaries and subduction zones. Please go to: http://pubs.usgs.gov/gip/dynamic/hotspots.html#anchor19620979 to answer the last two questions. 17. How did the Hawaiian Islands form and continue to form when they are positioned in the middle of the Pacific plate? 18. How can the direction of the Pacific plate movement be tracked by following the line of islands extending from Hawaii to the Emperor Seamount Chain. (See the “long trail of Hawaiian Hot Spots”)