How many lithospheric plates are there in all c cross

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3. How many lithospheric plates are there in all? C. Cross-Section Make a schematic cross-section of Geoworld along A-A'. Draw it in the box provided at the bottom of the map on page 9. Show the entire thickness of the lithosphere and part of the asthenosphere. Label the crust, mantle lithosphere and asthenosphere. D. Transform Faults There are several transform faults in the Elrond Sea. The only parts of these faults that are presently active are the parts between the segments of the Hobbit Ridge. 1. Using arrows, show the sense of motion on each of the active transform faults on the map. E. Earthquakes 1. Describe three places on the planet of Geoworld where you would expect large numbers of earthquakes. a. b. c. 2. The vast majority of earthquakes are caused by movement on faults. What types of faults would you expect at each location you described above (thrust, normal, strike- slip)? a.
“Geoworld” Plate Tectonics Lab 5 b. c. 3. For each location described above, record whether the earthquakes will have deep foci and/or shallow foci. a. b. c.
6 “Geoworld” Plate Tectonics Lab F. The Origin of the Volcanic Islands 1. The Galadriel Islands, Gandalf Islands and Gollum Island are all made of volcanic rocks. What are the differences in tectonic origin among these three groups of islands? 2. What type of volcanic rock would you expect Gollum Island to be composed of and why? G. Hot-spots and Absolute Movement Rates 1. Absolute motion of the Aragorn Ocean and the Bilbo Continent Notice the Gandalf Islands. They are analogous to the Hawaiian Islands on Earth. They form a linear chain that originated by the migration of the plate over a mantle hot spot. Mantle hot spots are assumed to be fixed relative to the center of the planet . All of the Gandalf islands are volcanic in origin but the easternmost and largest island--which is sitting directly over the hot spot--is the only one with active volcanoes on it. The rocks on the westernmost island have been dated by radiometric methods at 32 m.y . Measure the distance between the centers of the westernmost and easternmost Gandalf islands and use this information to calculate the absolute movement rate (in km/m. y.) of the Aragorn Ocean (and the Bilbo Continent, which is connected to it). Show your equations and explain where you got each of your numbers . Helpful hint: Pay no attention to the magnetic anomalies when answering this question. Absolute movement rate of the Aragorn Ocean = ____ km/m. y. 2. From careful measurements taken by satellites, we know that the Sauron Trench and
“Geoworld” Plate Tectonics Lab 7

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