GEOLOGY 306 Laboratory Instructor: TERRY J. BOROUGHS NAME: Examining the Terrestrial Planets (Chapter 20) For this assignment you will require: a calculator, colored pencils, a metric ruler, and your geology 305 textbook as a reference. Objectives for chapter 20: After you have completed this exercise, you should be able to: 1. List and describe the geologic processes that have shaped the landforms of the terrestrial planets; 2. Give an example of a feature on Earth or the Moon produced by each of the geologic processes that have shaped the landforms of the terrestrial planets; 3. List the primary geologic processes that have shaped the landforms of each of the terrestrial planets; 4. Describe the procedure for determining the relative ages of a planet s surface features. The following questions refer to Chapter 20, (PAGES 267 279 IN YOUR MANUAL, 7 th Ed.) or (Pages 325-340 in your manual, 8 th edition) (Read the questions from your manual and place your answers in the following spaces provided.) 1. Identify the geologic processes that modified the landscapes of the Earth and the Moon depicted in the following figures and/or photographs. The processes involve include the following: Volcanism, Tectonism (evidence of plate tectonics), Gradation (leveling of the surface due to erosion and deposition), and Impact Cratering. Figures and/or photographs Fig. 20.1 A & B Identify the geologic processes that modified these surfaces and/or landscapes (use Volcanism, Tectonism, Gradation, or Impact cratering Fig. 20.2 Fig. 20.3 & 20.4 Fig. 20.5 Fig. 20.6 A Smooth, dark areas of central figure in Fig. 20.6 2. Indicate the agent of gradation and/or specific process (if known) that is responsible for the feature the following figures: Figures and/or photographs Identify the agent of gradation and/or specific process (if known) that is responsible for the feature Inside the crater of Fig. 20.6 A Fig. 20.3 Fig. 20.4 3. Impact craters and volcanoes can both have craters. One has its crater rim along the ground s surface, whereas the other has its crater up atop a cone. The crater rim for an impact site is typically located: The crater rim for a volcano is typically located: Instructor: Ms. Terry J. Boroughs 1
4. Meteor Crater, Figure 20.5, has a diameter of approximately 1,200 meters. It is estimated that the object that produced it was about 25 meters across. How may times greater is the size of the crater than the object that produced it? Such a small object can produce such a large crater due to (high velocity, high momentum, high mass, or a combination of all of these.) (Pick the best answer.) 5. Despite being one of the best-preserved and youngest impact craters on Earth, Meteor Crater, Figure 20.5, shows signs or erosion. Do you see signs of weathering and erosion in the form of dry stream channels cutting through the rim of the crater, or debris from rock falls and/or rock slides at the base of the crater walls, or do you see a combination of both? 6. Which Lunar feature (figure 20.6 a, b, c, or d) most resembles Meteor Crater? 8. How are the surfaces of Mercury and the Moon similar? (What do they have in common?) 9. Figure 20.7A shows a close-up view of a portion of Mercury s surface. It is similar to certain features found on the Moon. Which figure of the Moon (Figure 20.6 A, B, C, or D) shows a feature similar to figure 20.7A? (Pick the best answer.) 10. Figure 20.7B shows a close-up view of a portion of Mercury s surface. It is similar to certain features found on the Moon. Which figure of the Moon (Figure 20.6 A, B, C, or D) shows a feature similar to figure 20.7B? (Pick the best answer.) 11. Of the four processes that alter a planet s surface, which one the most effective on Mercury? (In other words, which process is readily visible or common on the surface of Mercury?) 12. Why does Mercury show little evidence of erosion due to running water, wind, or ice? 13. Choosing from the processes that act on a planet s surface, (volcanism, tectonism, gradation, impact cratering) write the name of the process that is most likely responsible for the features in the following figures on Mercury. Be specific, for example, Gradation wind vs. Gradation ice. Figure 20.7 A: Figure 20.7 D (flat areas in lower left corner): Instructor: Ms. Terry J. Boroughs 2
14. Using these images of Mercury, figure 20.7C notice the trace of a cliff-like structure that has offset more than 1.6 kilometers (1 mile). Which of the four major geologic processes (volcanism, impact cratering, gradation, or tectonism) created this structure? (Pick the best answer.) 15. Using the full-disk image of Venus and the smaller images in Figure 20.8, do you see any of the following processes (volcanism, impact cratering, gradation, or tectonism) evident on the surface of Venus? Tectonism in the form of fracturing or faulting (yes or no): Volcanism (yes or no): Impact cratering (yes or no): Gradation (yes or no): If yes, what type(s)? 16. Choosing from the processes that act on a planet s surface, (volcanism, tectonism, gradation, impact cratering) write the name of the process that is most likely responsible for the following features (volcanism, impact cratering, gradation, or tectonism) evident on the surface of Venus? Figure 20.8 A: Figure 20.8 B: Figure 20.8 C: Figure 20.8 D: 17. In radar images, smooth surfaces appear darker, and rough, multi-faceted surfaces appear bright. These differences are not due to compositional differences like seen on the Moon, but instead due to the effects of weathering, erosion, etc. Do you think that the smooth surfaces are (Older or younger?) Pick one. Do you think that the rough surfaces are (Older or younger?) Pick one. 18. The gradational agent responsible for the feature in Figure 20.8 D is: 19. A. Is the central feature in Figure 20.8 C younger or older than the surrounding landscape? B. What type of structure is this feature? A. B. 20. The bright areas on the central global view of Venus (figure 20.8) show highly fractured ridges and canyons of the Aphrodite highlands. What geologic process produced these features: (volcanism, tectonic activity, gradation, or impact cratering)? (Pick the best answer.) Instructor: Ms. Terry J. Boroughs 3
21. Approximately 1000 impact craters have been identified on the surface of Venus. Do think this is (more or less) than the number on the surface of Mercury? 22. Identify the geologic processes that modified the landscapes of Mars depicted in the following figures and/or photographs. The processes involve include the following: Volcanism, Tectonism (evidence of plate tectonics), Gradation (leveling of the surface due to erosion and deposition), and Impact Cratering. Figures and/or photographs Fig. 20.9 A Fig. 20.9 B Fig. 20.9 C Fig. 20.9 E Identify the geologic processes that modified these surfaces and/or landscapes (use Volcanism, Tectonism, Gradation, or Impact cratering 23. Using the full-disk and the smaller images of Mars in or figure 20.9, do you see any of the following processes (volcanism, impact cratering, gradation, or tectonism) evident on the surface of Mars? Tectonism in the form of fracturing or faulting (yes or no): Volcanism (yes or no): Gradation (yes or no): Impact cratering (yes or no): If yes, what type(s)? 24. How does the Martian surface compare to the surfaces of Mercury and the Moon in regards to crater density (the number of craters in a given area)? Does Mars have more or fewer craters than Mercury? 25. Choosing from the gradational processes that act on the surface of Mars, write the name of the process that is most likely responsible for the features in the following figures. Be specific, for example, Gradation wind vs. Gradation ice. Figure 20.9 A: Figure 20.9 E: 26. The long linear feature near the center of the full-disk image of Mars is Valles Marineris, a large canyon system. Do you think Valles Marineris is (larger or smaller) than the Grand Canyon located in the U.S. (Pick the best answer.) 27. Do you think that Valles Marineris may have formed from tectonic activity? Do you think this tectonic activity is currently active? Instructor: Ms. Terry J. Boroughs 4
28. Because the subsurface of some regions on Mars contains abundant ice, impacts often generate ejecta with a mud-like consistency. Do you think the impact crater shown in figure 20.9 B exhibits this type of ejecta pattern? (yes or no) 29. Using Figure 20.9 C, Olympus Mons is one of four huge volcanoes in a region called Tharsis. Compare the surface of Olympus Mons to the surface of Mercury and the lighter regions of the Moon. Is the surface of Olympus Mons geologically (young, old, or about the same age) as the surfaces of Mercury and the lighter regions of the Moon? (Pick the best answer.) 30. Using Figure 20.6 Describe the origin and/or characteristics of the Lunar Maria and Lunar Highlands. Highlands: Maria: 31. Rocks brought back from the lunar Maria during the Apollo landings are about 3.2-3.8 billion years old. Therefore, are the lunar highlands (older or younger) than 3.2-3.8 billion years. (Pick the best answer.) 32. List these lunar features in order, from youngest to oldest: maria, highlands, rayed craters. Youngest: Middle: Oldest: 33. Are the rayed craters older or younger than the area around them? (Pick the best answer.) 34. Based upon the density of craters, the surface of Mars appears to be (older, younger, about the same age) as the Moon s highlands and (older, younger, about the same age) as the surface of Mercury. Write your answers here, don t circle them. 35. Considering its history, describe how the surface of Mercury is likely to change during the next billion years. 36. On a global scale, which planet looks more like Venus: Mercury or Mars? 37. Place the four terrestrial planets and our moon into sequence from the youngest, most modified surface to the oldest, less modified surface. Youngest: :Oldest Instructor: Ms. Terry J. Boroughs 5
38. Of the four terrestrial planets which is the: Most active: Least Active: 39. Using figure 20.12 Compare the southern half of the photograph to the northern half. Which surface is younger? Northern ½ or Southern ½ is younger? How did you know? 40. Using figure 20.12, How do you know that the craters in the Southern ½ are of various ages? Extra Credit Questions from page or 339 (Summary / Report Page for chapter 20): 1. What are the four major geologic processes that have shaped the surfaces of the terrestrial planets and the Moon? Give examples of landforms produced by these processes. Process: Example landform: Process: Process: Process: Example landform: Example landform: Example landform: 2. The surface of the Moon most resembles the surface of (Mercury, Venus, or Earth) whereas the surface of Venus is similar to that of (Earth or Mars)? 3. Which planet s surface has been mapped exclusively by Radar? Why is radar mapping used? 4. List the most significant geologic processes that shape or has shaped the surface of each of the terrestrial planets and the Moon. Most significant process on Mercury: Most significant process on Venus: Most significant process on Earth: Most significant process on Moon: Most significant process on Mars: Instructor: Ms. Terry J. Boroughs 6
5. Of the major gradational agents, (running water, gravity, wind, or ice) is the only one that alters the surface of all the terrestrial planets? (I.e. all terrestrial planets exhibit this gradational agent. (Pick the best answer.) 6. Using images from Mars figure 20.11 (B), do you think that these elongate and irregular features were produced by gradation and if so, specify the type of gradational process involved. 7. Briefly describe how the relative ages of various planetary surfaces can be determined. (I.E. what type of features or surface characteristics would indicate older surfaces vs. younger surfaces? Examining the Terrestrial Planets Lab Supplement 1. Tectonism / Tectonic activity A. Involves the movement of crustal rock by fracturing, faulting, or folding B. Can exhibit the following: Linear or gently curving factures and/or faults Fault scarps Folded terrain Mountain belts, mountain ranges Linear ridges 2. Volcanism A. Volcanism is the eruption of molten rock material (magma) and its associated gases, ash, etc. onto a planet s surface. B. Can exhibit the following: Steep, conical hills with summit craters or large caldera Calderas form as a result of summit collapse and may exhibit fractures in a concentric ring shape. Lava flows which can produce a lobe-shaped deposit with an undulating surface. Lava flows that fill craters and leave behind a smooth surface 3. Impact Cratering A. Impact craters are the consequence of rapidly moving meteorites and/or asteroids that strike the surface of a planet. B. Can exhibit the following: Central peaks or pinnacles in the center of the crater Ejecta blankets Ejecta rays Ringed crater rims Overturned crater rims Overlapping crater rims Crater chains, etc. Instructor: Ms. Terry J. Boroughs 7
4. Gradation A. The process that levels a surface to a common elevation by erosion and deposition is controlled by the surface environment. Gravity, temperature, and the presence of an atmosphere all play key roles. B. The major agents of gradation include the following: Running water Eroded stream channels Delta deposits Alluvial fans Lake sediments Ocean sediments, beaches, etc Gravity Wind Ice Materials become eroded and fall, flow, etc. due to the influence of gravity and include: Talus slopes (material collecting at the base of a steep surface, such as a cliff face or the walls of an impact crater Landslides, mudflows, avalanches, etc. often triggered by excess water Crater rims will become eroded and debris will start to fill the crater with eroded material, often burying the central peak, which can also become eroded All of the terrestrial planets have mass and therefore gravity!!! Wind requires and active atmosphere Typically only the fine-grained particles will be carried by the wind May produce wavy sand dunes May produce streaks of sediment when the wind carries some of the ejecta material in one direction, following an impact by a meteorite Requires the presence of water and other atmospheric compounds Ice is often very reflective and may appear white in pictures Ice and glaciers are very effective for scouring a surface flat and evening out the landscape. Often found closer to the polar regions of the Earth. Instructor: Ms. Terry J. Boroughs 8