What are the differences between a transcurrent & a transform fault? Use diagrams if you wish. (10 pts.).

Briefly describe the development of the concept of transform faults. How do transform & transcurrent faults differ? Discuss the role transform faults have in plate tectonic theory. Use sketches if you wish. (9 pts.)

Draw focal mechanisms for earthquakes that would be generated at locations (1), (2), & (3) on Figures 1 & 2 in the circles provided below. Darken compressional quadrants. (6 pts.)

Indicate the 2 active mantle hotspots in the North Atlantic on Figures 1 & 2 with blue triangles. (4 pts.)

Indicate the zone of andesitic/island arc volcanoes on Figure 2 with red triangles. (2 pts.)

At location (3) the ___________________________ plate is being subducted beneath the ___________________________ plate. (4 pts.)

Indicate on Figure 1 the approximate location of the pole of rotation for North American & Eurasian plate motion with a blue circle. (2 pts.)

Indicate the 7 transforms in the North Atlantic (not including the Caribbean) that are longer than 200 km on Figures 1 & 2 with red lines. (7 pts.)

Use the map of the Indian Ocean at the back of this test (Figure 1) to answer and do the following:

Draw focal mechanisms for earthquakes that would be generated at locations (1), (2), and (3) on Figures 1 and 2 in the circles provided below. Darken compressional quadrants.

At location 3, the ______________________ plate is being subducted under the _______________________ plate.

Indicate the 2 active mantle hotspots in the Indian Ocean on Figure 1 with blue triangles.

Indicate the zone of andesitic/island arc volcanoes on Figure 1 with red triangles.

With red lines on Figure 1, indicate: a) the only modern transform in the Indian Ocean longer than 400 km; b) 2 Late Cretaceous-Early Tertiary transforms longer than 500 km; c) 2 Early Cretaceous transforms longer than 500 km; and d) a Jurassic transform longer than 1500 km.

1. On the following page, a map of the seismicity of the world is provided. Draw in the plate boundaries of the major plates, & of the Nazca, Cocos, Juan de Fuca, Philippines, Caribbean, Scotia & Arabian plates. Label all major plates & the . Indicate convergent plate boundaries with a red , divergent plate boundaries with a blue , & major transform boundaries with a green , indicating the direction of motion on the transform. Complete the focal mechanisms indicated on the map. [You may get up & examine the World Ocean Floor map at the back of the room in conjunction with this exercise. Please go 1 at a time, however.] (25 pts.).

2. Briefly explain the reason that the seismic zones at the margins of the Pacific so broad compared to those occurring in the centers of the Atlantic & Indian Oceans, & in the Pacific south of North America to the west of South America. Use diagrams if you wish. (5 pts.).

3.a. How is the seismicity at 19‚N, 156‚W similar to that at 36‚N, 90‚W? (2 pts.).

b. How do these seismic zones differ? (3 pts.).

4. Briefly discuss what the differences in the spreading rates in the Atlantic & Pacific Oceans suggest about the driving forces for Plate Tectonics. (5 pts.).

Give the plate name that best fits each description below. Do not use a plate name more than once. (6 pts.)

1. Major plate consisting dominantly of oceanic lithosphere.

2. Minor plate consisting dominantly of oceanic lithosphere.

3. Major plate consisting dominantly of continental lithosphere.

4. Minor plate consisting dominantly of continental lithosphere.

5. Major plate nearly surrounded by the Mid-Ocean Ridge.

6. Major plate associated with the Himalayas.

7. Major plate associated with the Andes.

8. Major plate containing the western half of Iceland.

9. Major plate containing continental lithosphere that is being actively rifted.

10. Diamond-shaped minor plate south of Japan in the western Pacific.

11. Minor plate between North & South America.

12. A minor plate not listed above.

3. Major plate containing Los Angelos, California.

4. Large diamond-shaped plate south of Japan in the western Pacific.

7. A major or minor plate not listed above.

Give the name of the Major plate containing Los Angelos, California.