GEOL 109 Exam 2 Questions And Answers Pass Guaranteed| Graded A+.

Lesson 16 - Mercury: The Iron Planet - correct answers ... Would you be surprised if tomorrow's newspaper reported that a volcano was discovered erupting on Mercury? - correct answers Yes, that is not expected to happen on Mercury today. Mercury no longer has volcanic activity because its lithosphere is too thick for magmas to penetrate. What causes the differences between impact craters on the Moon and those on Mercury (the extent of the ejecta blanket and secondary cratering)? - correct answers different gravitational attractions on each planet Gravitational pull can affect the extent of crater ejecta and secondary craters. Both of these craters will extend for greater distances on planetary bodies that have less gravity. What do thermal models of Mercury's evolution suggest about its history? - correct answers That it developed a metallic core early in its history. The iron within Mercury separated out into a core early in the planet's history. The oldest types of terrains on both the Moon and Mercury are ________________________. - correct answers heavily cratered terrain Heavily cratered terrain is older than terrain with less craters, since cratering rate has decreased with time. Which of the following features are found on the Moon and Mercury? (Check all that apply) - correct answers -flood lavas -multi-ring basins -impact craters -faults related to contraction NOT: dunes All but dunes are found on both the Moon and Mercury. Dunes do not exist because there is not atmosphere to move particles to form them. Which image shows a feature that formed by contraction of Mercury's surface? - correct answers B Contraction produces lobate features, while extension produces linear valleys. Which of the following tectonic processes are thought to have occurred on Mercury? (Check all that apply) - correct answers -thrust faulting due to contraction of the planet -graben formation due to extension Both extensional and contractional tectonics have occurred on Mercury. Extension produces graben while contraction produces thrust faults. It is important to remember extension cannot produce thrust faults nor contractions produce grabens. Mercury's smooth plains ____________________. - correct answers may be similar in origin to the lunar maria The smooth plains have few craters compared to the heavily cratered terrain and resemble the lunar maria. One of these impact craters is on the Moon and the other is on Mercury. Click on the one on Mercury. - correct answers A Crater A has secondary impacts close to the rim, while B has secondary craters farther from the crater. What explains for Mercury's iron large core? Choose the two most likely. - correct answers -Mercury formed near the Sun in a zone that was oxygen-poor and rich in metallic iron. -A large impact stripped away the silicate shell from an already differentiated Mercury. There are two main theories as to why Mercury has such a large iron core. The first is, Mercury accreted in an oxygen-poor area that allowed iron to remain in its metallic state allowing close to all of the iron to segregate in the core. The second hypothesis is a giant impact knocked off much of Mercury's mantle without affecting the core, so now the core is large compared to Mercury's diameter. Lesson 17 - Mars: The Red Planet - correct answers ... Although both Mercury and Mars have similar gravity fields, Mars has an atmosphere whereas Mercury does not. What is a possible explanation? - correct answers Mars is more volatile rich. Because Mars accreted further from the Sun than Mercury, Mars has a greater amount of volatiles. These volatiles were outgassed and released past the surface of Mars where they were trapped by the gravity field of Mars. Which planetary body has (basically) no magnetic field today? - correct answers Mars Though Mars is larger than Mercury it does not have a present magnetic field. There is evidence within martian rocks that show there was one in the past, but there is not an active one today. Which of the following are important differences between the nature of the martian hemispheres (north and south)? (Mark all that apply) - correct answers -ages -number of young volcanoes and volcanic plains -elevations -the number of impact craters The northern and southern hemispheres are very different in almost every aspect. Including ages, crater density, volcanic activity, and elevations. What is the evidence for ground ice (or ground water) on Mars? Choose all correct answers. - correct answers -fluidized crater-ejecta patterns -chaotic (collapse) terrains Evidence of water on Mars is seen in impact features produced by melted water and the chaotic terrain produced by flowing water. This is a colored topographic map of Mars, with high elevations in brown and white and low elevations in blue. Click on the VALLES MARINERIS. - correct answers blue, looks like scratches or a big scar This is a colored topographic map of Mars, with high elevations in brown and white and low elevations in blue. Click anywhere in the CRATERED HIGHLANDS. - correct answers all the yellow, cratered part This is a colored topographic map of Mars, with high elevations in brown and white and low elevations in blue. Click anywhere in the YOUNGEST PLAINS. - correct answers on top, blue, smooth, uncratered This is a colored topographic map of Mars, with high elevations in brown and white and low elevations in blue. Click on the volcanoes of the THARSIS BULGE. - correct answers looks like a pyramid with one big volcano at top and three on bottom This is a colored topographic map of Mars, with high elevations in brown and white and low elevations in blue. Click on a THICK SHEET OF ICE. - correct answers red part at the bottom How did these vast valleys on Mars form? - correct answers The outflow valleys were eroded by liquid water. Flowing water erodes the landscape and produces sinuous stream channels that flow from higher elevation (left) to lower elevation (right). Lesson 18 - Mars: Atmosphere and Hydrosphere - correct answers ... Martian valley networks are ____________________________________. - correct answers restricted in occurrence to the oldest part of Mars Water flows from higher to lower elevation. This means, on Mars, the water channels will flow from the southern highlands to the northern lowlands. The outflow channels on Mars are different from river systems on Earth in what way? - correct answers they appear to come from below the surface and lack extensive collection systems The lack of similar tributaries connected with the large outflow channels suggest water did not flow from other places into a larger channel. Instead, the outflow channels connection with chaotic terrain suggest the water came from melting large quantities of water ice in the chaotic terrain. This melting released huge volumes of water that produced the outflow channels. The largest dune fields on Mars are ____________________. - correct answers in the polar regions The largest dune fields are seen in the polar regions of Mars. Why does Mars lack a well-integrated hydrologic system? - correct answers It is too cold. No flowing water presently the vast amounts of water ice in the ground and polar regions suggest it is too cold for water to flow as a fluid on the surface today. Which of these geologic features are not found on all of the following planets—Mercury, Mars, and Earth? (Choose all that apply) - correct answers -sand dunes -river valleys We have not seen either of the features on Mercury or the Moon. Both are too dry and cold to have had or have flowing water and no atmosphere to produce dunes. What is the probable origin of the dark colored features in this image of the surface of Mars? It is about 20 km across. - correct answers These features are dunes shaped by the wind. What is the probable origin of the features shown in this image of the surface of Mars? - correct answers These are dendritic channels eroded by liquid water. What is the probable origin of the irregular ovals in this image of the surface of Mars? - correct answers Sublimation of ground ice caused collapse of the surface, making pits. Lesson 19 - Mars Volcanism and Tectonism - correct answers ... What is the Tharsis "bulge"? - correct answers A large dome that was associated with the development of an extensive fracture system. Multiple, large volcanoes sit atop the Tharsis "bulge." This bulge is associated with fractures that radiate away from the bulge. The presence of lava volcanoes is evidence for an ancient mantle plume that may have risen in this location, lifting the crust and producing volcanism. Mars and Mercury differ substantially in what way(s)? Choose all that apply. - correct answers -the composition of their atmospheres -their densities -the size of their cores -their surface temperatures (everything BUT: the strength of their gravity fields) As seen in this, and previous lessons, Mars is a much different planet than Mercury even though both are terrestrial planets. This shows that even generally similar planets are not exactly alike and have undergone different histories and evolutions. Graben formation is usually associated with which process? - correct answers lithospheric extension Grabens are fractures that form from expansion and extension of the lithosphere. Which features of Mars indicate a distinctive geologic process that doesn't operate on Mercury or the Moon? - correct answers Domal upwarps of the lithosphere and associated fractures caused by mantle plumes. Formation of lithospheric domes but rising mantle plumes are not seen on the Moon or Mercury, while Mars has several. Note the long light-toned feature that extends diagonally across this image on Mars. Which phrase(s) best describe its possible origin? Choose all that apply. - correct answers -low viscosity lava flow -basaltic lava flow Just like on the Moon, basaltic (low viscosity) lava flows form long flows with lobate margins. Silicic, or high viscosity, lavas cannot produce this morphology because they do not form as readily. While will look like ice and landslides, are not near as long or narrow. Examine this image of Mars carefully. What feature is a small shield volcano? - correct answers right beneath highest volcano looking thing in picture Volcanic shields are low reef volcanoes that are reminiscent of Greek shields. These volcanoes are produced by low viscosity lava that cannot build up much topography. Click on the part of this image of Mars that has evidence of tectonic extension. - correct answers striped looking part on right side Extension of the lithosphere produces linear valleys in the crust. Click on the feature that is the result of tectonic contraction on Mars. - correct answers lines along left side of picture Contraction (shortening) produces lobate and positive relief structures like wrinkle ridges. Mass movement commonly affect steep slopes on the planets. Click on a landslide in this image of Mars. - correct answers looks like a tongue Landslides are a mass movement process that produces a deposit that look like tongues that stick out from mountainous terrain. These landslides result from debris flowing off of a topographically high area. Click on a young volcanic plain in this colored shaded relief map along Mars' Great Escarpment. - correct answers in the top left corner, blue, smooth Low viscosity, basaltic lava flows smooth out surfaces on planets by filling in cracks and craters and usually contain abundant wrinkle ridges. Lesson 20 - Mars: History and Life(?) - correct answers Which "planet's" interior stayed warm longer? - correct answers Mars What is the probable origin of the smooth plains in the Northern Hemisphere of Mars? Choose all that apply. - correct answers -the depression probably started to form as a giant impact crater that covered half of the planet -sediment from a series of temporary seas smoothed it out Does Mars have a plate tectonic system like Earth? - correct answers No, it lacks a system of moving plates. What was the sequence of events that shaped this part of Mars? Put the following descriptions into the proper order with the oldest on bottom and youngest at the top. Not all descriptions apply and should be left out. - correct answers 1. Youngest -- formation of rampart crater 2. Second youngest -- extensional tectonics 3. Second oldest -- eruption of lava plains 4. Oldest -- development of shield volcano These diagrams show the history of Mars but they are not in the correct chronologic order. Put the event into the proper order with the oldest first and the youngest last. - correct answers oldest -looks like sun with rays coming out -bare with no rays -a little bit of light color on top -about half is light color -same as above but with more craters -has most spots and marks youngest Lesson 21 - Venus - correct answers ... Which of the following statements about Venus is (are) true? Choose all that apply. - correct answers - The diameter of Venus is almost the same as that of Earth. - The atmospheric gases create a large greenhouse effect. If Venus is so close to Earth, why has it taken so long to understand what the solid surface of Venus is like? - correct answers Its surface is buried beneath a very cloudy atmosphere. The carbon dioxide atmosphere is too thick to visibly see through. Other light wavelengths (radar) are needed to pierce the atmosphere. Which of the following is a major difference between Venus and Earth? - correct answers atmospheric composition Though the size, density, gravity, and volume are near identical between Earth and Venus. Venus does have some major differences from that of Earth, especially atmospheric composition. Earth's atmosphere is dominated by nitrogen and oxygen, while Venus's atmosphere is almost all carbon dioxide. Radar images of Venus show all of the following except __________. - correct answers river valleys Radar images do not show any dendritic valleys nor any evidence for liquid water on Venus. Study this colored topographic map of Venus and identify the following provinces using the letters on the map. Blue is low, with green, yellow, red, and white progressively higher. - correct answers A (blue) - a lowland B (red, center) - a highland C (red and white) - an upland The uplands are large plateaus and encompass large areas. The highlands are domes that create topographic highs, they do not take up as much area as the uplands. The lowlands are the topographic lows marked as blue. Lesson 22 - Venus: Atmosphere and Craters - correct answers ... Which of the following statements is an accurate description of the atmosphere of Venus? - correct answers The venusian atmosphere is rich in carbon dioxide. The composition of the venusian atmosphere is about 96% carbon dioxide. It is a secondary atmosphere that formed from outgassing. The composition and thickness of the atmosphere trap incoming heat, allowing the planet to become hot enough on the surface to melt lead. While Venus's atmosphere is incredibly dense (and the most dense of the inner planets), it is not the most dense. That title belongs to one of the Gas Giants. Conditions on Venus are such that which of the following are true? Choose all that apply. - correct answers - Pure lead would be a liquid on its surface. - The pressure is about 90 times that on Earth. The greenhouse effect is so strong on Venus, it raises the surface temperature high enough to melt lead. And the atmosphere is much more dense than Earth. We know that carbon dioxide was not sequestered into limestones, because the carbon dioxide would be gone from the atmosphere. And since there is no water vapor on Venus, water cannot precipitate. While there is sulfuric acid in the atmosphere, it does not result in the weathering of rocks on the surface. The acid will evaporate before it reaches the surface. What is one of the major causes of the high temperatures on the surface of Venus? - correct answers the greenhouse effect The high concentration of carbon dioxide in the atmosphere traps heat. Large amounts of water (as gas or liquid) on Venus _________. - correct answers have probably been lost to space and by contamination with surface materials Since there is no water observed on Venus, and there most likely was (since we have water on Earth), the water must have been lost to space. Impact craters on Venus that are larger than about 30 km in diameter are __________. - correct answers not common because of the planet's dynamic interior and young surface The surface of Venus is too young to have large craters. They would have been destroyed. The structure and appearance of impact craters changes with size. Study these radar images of impact craters on Venus. Arrange them from smallest (at the top) to largest (at the bottom). - correct answers - mostly black with a little bit of white - little white circle surrounded by wide white ring - circles have thinned, more black - looks like powder spewing out from a black circle Small craters are irregular and occur in clusters. With progressively larger craters have terraces, central peaks, and peak rings, and the largest are multi-ring basins Click on the letter of the area of this radar image of Venus that has been shaped by eolian (wind) processes. - correct answers B (looks like little bits of mud or something running down) Wind can produce a variety of features, including streaks, which are labelled as B. The others are tectonic or volcanic features. About how old is the surface of Venus as judged from the abundance of meteorite impact craters? - correct answers Millions of years old. Because there are few impacts, and even fewer large impacts, the surface is very young. On the order of millions of years old. Lesson 23 - Venus: Volcanism and Tectonism - correct answers ... The two large volcanoes of Venus, Theia Mons and Rhea Mons, lie on the flanks of a structure similar to which of the following? - correct answers The East African Rift valley. Devana Chasma is an extensional feature. This is most similar to the East African Rift valley (also extensional). A subduction zone produces contractional features and thickens the crust. Volcanic hot spots form volcanic edifices. The island arc is also volcanic not tectonic. Folded mountain belts are important tectonic landforms. Which of the following statements is the most accurate description of folded mountain belts? - correct answers They are found around the margins of highlands on Earth and Venus. These features are not seen across all of the terrestrial planets. The sinuosity and intertwining of the ridge belts are a distinctive feature are evidence of contractional and not extensional tectonics. Thus, they are not dominated by normal faults but by thrust faults. What is the most important factor in the volcanic and tectonic evolution of Venus as compared to Mars? - correct answers The size of Venus which makes it cool slower than Mars. As we have discussed with Mercury and Mars (and terrestrial planets in general). The volcanic and tectonic evolution is determined by the planetary body's size. The larger the planet, the more heat it has, and the longer volcanic and tectonic activity will occur. Which of the following are major extensional features on Venus? - correct answers Rift valleys and grabens associated with lithospheric domes. Rift valleys and grabens form by extension. While ridge belts are contractional and Isthar Terra is also contractional. What is the most likely cause of the sinuous feature that extends across this radar image of Venus? The area is a few hundred kilometers across. - correct answers Erosion by hot flowing magma. These features are formed by flowing lava that erodes down into the rock. The sinuous nature and small width of the channels suggest it is produced by flowing lava. We know they cannot form by water, because there is no water on Venus. The sinuous nature excludes extensional faulting, and there not being many, interconnected, sinuous faults excludes contractional faulting. What is the most likely cause of the radical tectonic features on this part of Venus? The image is a few hundred kilometers across. - correct answers Vertical doming Rising plumes can dome the crust and produce radial fractures. Other contractional or extensional features are usually linear and only form in one direction. Lesson 24 - Venus: History - correct answers ... What is the approximate age of the surface of Venus? - correct answers The average age of the surface is much younger than any of the Moon's major terranes. Venus is a large planet and cooled slowly, unlike the small planetary bodies of the Moon and Mercury. The slow cooling would allow for volcanism and tectonic activity to occur and resurface Venus, or possibly, still. Does Venus have a plate tectonic system like the Earth? (Mark all that apply.) - correct answers - NO (check all the no answers) There are multiple reasons Venus does not have plate tectonics. Venus does not have a shallow asthenosphere for the plates to slide on because there is not water present to lower the melting temperature of the mantle. In addition, the high temperature of the surface makes the materials at the surface less dense, and perhaps they cannot subduct because of this. So, instead of plate tectonics, Venus' volcanism and tectonics are the result of mantle plumes. Why is the history of Venus so different from that of Mars? - correct answers Venus is significantly larger than Mars and cooled slowly. Heat controls the geologic history of planets, and in turn, heat is controlled by how large the planetary body is. The larger the planet, the longer it stays warm, and the longer the planet can have active volcanism and tectonism. What would have happened on Venus if it had been cool enough for liquid water to form? - correct answers Carbonate minerals may have formed in the water and removed the carbon dioxide from the atmosphere. Large bodies of liquid water and carbon dioxide in the atmosphere, can mix to precipitate carbonate minerals. Since Venus has a carbon dioxide-rich atmosphere, it can be assumed, if Venus had liquid water, there would be a lot of carbonate minerals on the surface. It is very possible that Venus once had more water and has lost it to space over the millenia. - correct answers True It is possible Venus had water early on in the planet's history, and just like Earth outgassed water. However, because of the high surface temperature of Venus, the water would have not been stable and was expelled into space as a vapor. Lesson 25 - Earth: Our Planet - correct answers ... Which gas was most efficiently removed from the Earth's atmosphere since the advent of life? - correct answers Carbon Dioxide -- CO2 The first forms of life on Earth were single-celled organisms that breathed in carbon dioxide by photosynthesis and produced free oxygen. Which of these factors control the Earth's hydrologic system? (Mark all that apply.) - correct answers ALL: - gravity - solar energy - topography - temperature All of these factors help control the hydrosphere. Topography and gravity bring water down in streams to the ocean, while solar energy and temperature determine if water will evaporate or condense and precipitate. The presence of oxygen (O2) in a planet's atmosphere is strong evidence for ___________________. - correct answers the presence of living organisms The only process we know of that produces free oxygen is photosynthesis. Which event drastically modified Earth's geologic history about 3.5 billion years ago? - correct answers The advent of life. Evidence for life is seen in rocks that are 3.5 billion years old. Karst topography is produced _______________. - correct answers because limestone is relatively soluble in water Karsts form by ground water dissolving limestones, since limestones are soluble. Considering the ways it forms, deforms, and crystallizes, glacial ice can be considered to be which of the following? - correct answers a metamorphic rock