GEOL360 Structural Geology
Name______Date______
Problem Set #3: Apparent Dip, Angles and Orientations
Part 1. Apparent dip
1. In a mine, a tabular dike has an apparent dip of 14°, 270° in one tunnel and 25°, 169° in another tunnel (here we use azimuth directions). Using a stereonet, what is the attitude (strike and dip) of the dike? ______
1. Along a vertical railroad cut a bed has an apparent dip of 20°, N62°W. The bed strikes N67°E. What is the true dip? ______
1. Suppose a fault strikes N10°E and its apparent dip trends S26°E and plunges 35°. Using a stereonet, determine the true dip of the fault.
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Part II. Angle between two lines
1. What is the angle between the following two lines? a. 35°, S10°E a. 15°, N23°W ______
1. What is the angle between the following two lines? a. 12°, N8°E a. 40°, S19°W ______
1. What is the angle between the following two lines? a. 70°, S38°E a. 49°, N15°E ______Part III. Angle between two planes
1. What is the angle between the following two planes? a. N27°E, 85°SE a. N89°W, 7°NE ______
2. What is the angle between the following two planes? a. 315°, 20°NE a. 165°, 24°SW ______
3. What is the angle between the following two planes? a. 014°, 10°SE a. N18°W, 37°NE ______
Part IV. Orientation of the intersection of two planes:
1. Determine the orientation of the intersection of the following two planes: a. N70°E, 80°SE a. N15°W, 35°NE ______
2. What is the orientation of the intersection of the following two planes? a. 170°, 19°SW a. 265°, 55°NW ______
3. What is the orientation of the intersection of the following two planes? a. 065°, 45°NW a. 310°, 28°NE ______Part V. Orientation of a line within a plane (e.g., rake):
1. While in the field you measure striations that rake 60°SW along a fault that trends N35°W, 18°SW. What is the orientation of the striations? ______
2. While in the field you measure striations that rake 25°SW along a fault that trends N28°E, 50°SE. What is the orientation of the striations? ______
3. In the field you measure mineral lineations that rake 70°NE in a quartzite bed that trends 345°, 56°NE. What is the orientation of the mineral lineations? ______
4. In the field you measure stetched belemnites that rake 45°NW in a limestone bed that trends 215°, 30°NW. What is the orientation of the belemnites? ______