Geology 109 Exam 2 Written With Accurate Answers Graded A+.

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. 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 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 oldest types of terrains on both the Moon and Mercury are ________________________. - correct answers heavily cratered terrain Which of the following features are found on the Moon and Mercury? (Check all that apply) - correct answers flood lavas multiring basins impact craters faults related to contraction Which image shows a feature that formed by contraction of Mercury's surface? - correct answers B 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 Mercury's smooth plains ____________________. - correct answers may be similar in origin to 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 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. 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 Which planetary body has (basically) no magnetic field today? - correct answers Mars 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 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 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 horizontal lines that are right of the volcanoes 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 cratered region on bottom of picture 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 blue region at top of the picture 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 they look like volcanoes 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 pink strip at bottom of image How did these vast valleys on Mars form? - correct answers The outflow valleys were eroded by liquid water Martian valley networks are ____________________________________. - correct answers restricted in occurrence to the oldest parts of Mars 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 largest dune fields on Mars are ____________________. - correct answers in the polar regions Why does Mars lack a well-integrated hydrologic system? - correct answers It is too cold. 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 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 it make pits. What is the Tharsis "bulge"? - correct answers A large dome that was associated with the development of an extensive fracture system. Mars and Mercury differ substantially in what way(s)? Choose all that apply. - correct answers -The compositions of their atmospheres. -Their densitites. -The sizes of their cores. -Their surface temperatures. Graben formation is usually associated with which process? - correct answers lithospheric extension 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. 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 Examine this image of Mars carefully. What feature is a small shield volcano? - correct answers volcano second from the top Click on the part of this image of Mars that has evidence of tectonic extension. - correct answers vertical lines on right of picture Click on the feature that is the result of tectonic contraction on Mars. - correct answers C; on left of picture Mass movement commonly affect steep slopes on the planets. Click on a landslide in this image of Mars. - correct answers looks like a landslide Click on a young volcanic plain in this colored shaded relief map along Mars' Great Escarpment. - correct answers blue area on left side of picture 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 fo rampart crater 2. Second youngest- extensional tectonics 3. Second oldest- eruption of lava plains 4. Oldest- Development of shield volcano Lesson 20 question 5 - correct answers Oldest to youngest 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. Which of the following is a major difference between Venus and Earth? - correct answers atmospheric composition Radar images of Venus show all of the following except __________. - correct answers river valleys 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 highland - B (red) An upland- C (pink) A lowland- A (blue) Which of the following statements is an accurate description of the atmosphere of Venus? - correct answers The venusian atmosphere is rich in carbon dioxide. 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. What is one of the major causes of the high temperatures on the surface of Venus? - correct answers the greenhouse effect Large amounts of water (as gas or liquid) on Venus _________. - correct answers have probably been lost to space and by combination with surface materials. 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 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 smallest: -lots of black surrounding -lots of light gray surrounding - light ring in middle -looks biggest Click on the letter of the area of this radar image of Venus that has been shaped by eolian (wind) processes - correct answers B About how old is the surface of Venus as judged from the abundance of meteorite impact craters? - correct answers Millions of years old. 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. 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. 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. The size of Venus which makes it cool slower than Mars. - correct answers Rift valleys and grabens associated with lithospheric domes. 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. 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 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. Does Venus have a plate tectonic system like the Earth? (Mark all that apply.) - correct answers -No, the high surface temperature may prevent the lithosphere from becoming dense enough to subduct back into the mantle. -No, Venus may lack a shallow asthenosphere. -No, Venus is water-poor which makes the melting point of the mantle higher than on Earth. -No, Venus is dominated by mantle plume convection instead. Why is the history of Venus so different from that of Mars? - correct answers Venus is significantly larger than Mars and cooled slowly. 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. It is very possible that Venus once had more water and has lost it to space over the millenia. - correct answers True Which gas was most efficiently removed from the Earth's atmosphere since the advent of life? - correct answers Carbon Dioxide-CO2 Which of these factors control the Earth's hydrologic system? (Mark all that apply.) - correct answers -gravity -solar energy -topography -temperature The presence of oxygen (O2) in a planet's atmosphere is strong evidence for ___________________. - correct answers the presence of living organisms Which event drastically modified Earth's geologic history about 3.5 billion years ago? - correct answers The advent of life. Karst topography is produced _______________. - correct answers because limestone is relatively soluble in water Considering the ways it forms, deforms, and crystallizes, glacial ice can be considered to be which of the following? - correct answers a metamorphic rock On Earth and Mars, how is loess deposited? (Mark all that apply.) - correct answers -As a blanket which mantles the landscape -By the wind -As dust-sized particles A weak layer within Earth which behaves like a viscous fluid is _________________. (Mark all that apply.) - correct answers -the outer core -the asthenosphere How thick is the Earth's atmosphere? - correct answers Between about 10 and 200 km thick. Which of the following is not usually associated with a terrestrial subduction zone? - correct answers basaltic shield volcanoes The Earth's oceanic crust is composed mostly of ____________________. - correct answers igneous rocks of basaltic composition Which of the following are true about mid-ocean ridges? (Select all that apply.) - correct answers -the site of the production of oceanic crust -has abundant extensional normal faults On Earth, lithospheric plates converge at which plate boundary? - correct answers subduction zones Where are the oldest rocks on Earth found? - correct answers In its continental shields. Why did continents develop on Earth and not on the Moon, Mercury, or Mars? - correct answers Only Earth has subduction zones. Click on the letter of the cross section of Earth that shows where the mafic ocean crust is made. - correct answers C Click on the letter of the cross section of Earth that shows where the silicic continental crust is made. - correct answers D Click on the letter on this shaded relief map that shows a transform plate boundary. - correct answers B Click on the letter on this shaded relief map that shows a divergent plate boundary. - correct answers C Click on the letter on this shaded relief map that shows a convergent plate boundary. - correct answers D How many meteorite impact craters have been identified on Earth? - correct answers About 100 What explains the number of impact craters that have been identified on Earth? (Select all that apply.) - correct answers -Earth has few impact craters because its ancient surface has been extensively modified by erosional processes. -Earth has few impact craters because many were obliterated by subduction, mountain building, and volcanism. How did the Chicxulub impact affect Earth? - correct answers The impact triggered a series of climate changes that led to the extinction of many species, including dinosaurs. These images show impact craters on the Moon, Mars, Venus, and Earth. Each has distinctive features because of the geologic processes that affect the surface. Click on the image of the crater on Earth. - correct answers A These images show impact craters on the Moon, Mars, Venus, and Earth. Each has distinctive features because of the geologic processes that affect the surface. Click on the image of the crater on the Moon? - correct answers B These images show impact craters on the Moon, Mars, Venus, and Earth. Each has distinctive features because of the geologic processes that affect the surface. Click on the image of the crater on Mars? - correct answers C These images show impact craters on the Moon, Mars, Venus, and Earth. Each has distinctive features because of the geologic processes that affect the surface. Click on the image of the crater on Venus? - correct answers D These images show 5 stages in Earth's 4.6 billion year evolution. Sort the images from youngest (present day) at the top, to oldest (primordial Earth) at the bottom. - correct answers Youngest: C E A D B Oldest: Why is the Earth a dynamic planet, whereas the Moon and Mercury have undergone very little change during the last 3.5 billion years? (Select all that apply.) - correct answers -A major difference is that Earth is much larger than the other two. -The Moon and Mercury lack atmospheres, but Earth has retained one, which has greatly modified the surface. What are some of the ways that the advent of life modified Earth's atmosphere/hydrosphere and the geologic processes which act on its surface? (Select all that apply.) - correct answers -Using energy from the Sun, organisms consumed carbon dioxide and released oxygen into the atmosphere. -The oxygen produced by living things oxidized (weathered) the minerals and rocks at the surface. -The evolution of creatures that make shells of calcium carbonate helped remove carbon dioxide from the atmosphere. -Large quantities of dissolved iron were removed from the ovean to form delicately banded iron-rich sediments In what way is the history of Earth similar to the history of the Moon? - correct answers Both "planets" once had heavily cratered surfaces. What are some of the main reasons Venus and Earth have such different histories? - correct answers Venus was hot enough that liqu