Exam 2 Quizzes

PHOTO - This is a colored topographic map of Mars, with high elevations in brown and white and low elevations in blue. Match the letters with the correct geologic province. Valles Marineris cratered highlands youngest plains volcanoes of Tharsis bulge an ice sheet

VM - D highlands - B youngest - A volcanoes - C ice sheet - E All the above and labelled locations are the geologic provinces discussed in section 6.3.

PHOTO - 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. Which of the images is of crater on Venus?

D

PHOTO - One of these impact craters is on the moon and the other is on Mercury. Which one is on Mercury?

A Crater A has secondary impacts close to the rim, while B has secondary craters farther from the crater.

Which of the following statements about Venus is (are) true? Choose all that apply. A. The diameter of Venus is almost the same as that of Earth. B. It is the only planet without a natural satellite. C. The atmospheric gases create a large Greenhouse effect. D. Venus is heavily cratered like the moon.

A & C

PHOTO - What image shows a feature that formed by contraction of Mercury's surface?

B Contraction produces lobate features, while extension produces linear valleys.

Graben formation is usually associated with which process? A. catastrophic flooding B. lithospheric contraction C. lithospheric extension D. lithospheric cooling E. dust storms

C Grabens are fractures that form from expansion and extension of the lithosphere.

PHOTO - Which part of this image of Mars has evidence of tectonic extension?

D Extension of the lithosphere produces linear valleys in the crust.

What is the evidence for ground ice (or ground water) on Mars? Choose all correct answers. A. fluidized crater-ejecta patterns B. faulted plains C. chaotic (collapse) terrains D. the great Valles Marineris

A & C Evidence of water on Mars is seen in impact features produced by melted water ice and the chaotic terrain produced by flowing water.

Which of the following features are found on the Moon and Mercury? (Check all that apply) A. flood lavas B. dunes C. multiring basins D. impact craters E. faults related to contraction

A, C, D & E 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.

What is one of the major causes of the high temperatures on the surface of Venus? A. high volcanic activity B. the greenhouse effect C. high radioactive element concentrations D. tidal heating

B The high concentration of carbon dioxide, in the atmosphere, traps heat.

PHOTO - Which of the letters on this shaded relief map is a transform plate boundary?

B Transform plate boundaries often offset segments of mid-ocean ridges.

Which event drastically modified Earth's geologic history about 3.5 billion years ago? A. The advent of life. B. Beginning of a period of intense impact cratering. C. Outgassing of the atmosphere. D. The onset of mantle convection to form plumes and associated volcanoes.

A Evidence for life is seen in rocks that are 3.5 billion years old.

It is very possible that Venus once had more water today and has lost it to space over the millenia. A. True B. False

A 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.

On Earth, lithospheric plates converge at which plate boundary? A. oceanic ridges B. subduction zones C. transform faults

B Trenches form at the boundary between two converging, lithospheric plates.

PHOTO - 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. Which of the images is of crater on Mars?

C

PHOTO - What is the most likely cause of the radical tectonic features on this part of Venus? A. NW-SE extension B. E-W compression C. Vertical doming D. Vertical down-warping

C Rising plumes can dome the crust and produce radial fractures. Other contractional or extensional features are usually linear and only form in one direction.

If Venus is so close to Earth, why has it taken so long to understand what the solid surface of Venus is like? A. Its surface is buried beneath a very cloudy atmosphere. B. The temperature is so high the normal imagining is not possible. C. It is covered by a thick layer of water (an ocean). D. The radiation environment is so harsh that the cameras do not function.

A The carbon dioxide atmosphere is too thick to visibly see through. Other light wavelengths (radar) are needed to pierce the atmosphere.

Why did continents develop on Earth and not on the Moon, Mercury, or Mars? A. Only Earth has subduction zones. B. Only Earth has mid-ocean ridges. C. Only Earth has mantle plumes. D. Only Earth has a lithosphere thick enough to support them.

A The continents are made of felsic materials, as we saw in the text, felsic magma is only produced at subduction zones. Since none of the other planets have subduction zones, there is not way for the planets to form continents.

PHOTO - 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. Which of the images is of crater on Earth?

A

Does Mars have a plate tectonic system like Earth? A. Yes, it has mobile plates of lithosphere. B. No, it lacks a system of moving plates.

B

PHOTO - 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.

Youngest - Rampart Crater Extensional tectonics Eruption of Lava Oldest - Development of Shield volcanoe.

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.) A. A major difference is that Earth is much larger than the other two. B. Because Earth is closer to the Sun than the Moon and Mercury, its hydrologic system has been more actively eroding the surface. C. Because Earth has a moon and the others do not, it has been tidally heated and kept warm and active for a long time. D. The Moon and Mercury lack atmospheres, but Earth has retained one, which has greatly modified the surface.

A & D There are two main ways a planet can be change and be dynamic. The first is from internal heat, which drives volcanism and tectonism burying and destroying previous surface features. The second is presence of an atmosphere that can move sediment and reshape the surface by wind and flowing water.

On Earth and Mars, how is loess deposited? (Mark all that apply.) A. As a blanket which mantles the landscape. B. By the wind. C. As dust-sized particles. D. By running water. E. On the floors of their oceans.

A, B, C Loess are dust-sized particles that are transported by wind and deposited as blankets on the Earth's surface.

Does Venus lack a plate tectonic system like the Earth? (Mark all that apply.) A. No, the high surface temperature may prevent the lithosphere from becoming dense enough to subduct back into the mantle. B. No, Venus may lack a shallow asthenosphere. C. No, Venus is water-poor which makes the melting point of the mantle higher than on Earth. D. No, Venus is dominated by mantle plume convection instead. E. Yes, Venus and the Earth both have a system of plate tectonics.

A, B, C & D 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.

Which of the following are important differences between the nature of the martian hemispheres (north and south)? (Mark all that apply) A. ages B. number of young volcanoes and volcanic plains C. elevations D. the number of impact craters

A, B, C and D The nothern and southern hemispheres are very different in almost every aspect. Including ages, crater density, volcanic activity, and elevations.

About how old is the surface of Venus as judged from the abundance of meteorite impact craters? A. Thousands of years old. B. Millions of years old. C. Billions of years old. D. So varied in age that a single age cannot be given.

B Because there are few impacts, and even fewer large impacts, the surface is very young. On the order of millions of years old. (0.5 billion)

How did the Chicxulub impact affect Earth? A. The impact did little to affect the Earth since about half of the crater was in the ocean. B. The impact appears to have triggered large outpourings of basaltic lava that filled the basin. C. The impact triggered a series of climate changes that led to the extinction of many species, including dinosaurs. D. The Gulf of Mexico was created by this huge impact.

C

PHOTO - Mass movement commonly affect steep slopes on the planets. Which letter labels a landslide on Mars?

C

PHOTO - Which part of this image of Mars has evidence of tectonic contraction?

C

What is the approximate age of the surface of Venus? A. Most of the surface of Venus is about the same age as the heavily cratered lunar highlands. B. The smooth volcanic plains of Venus are about the same age as the lunar maria. C. The average age of the surface is much younger than any of the Moon's major terranes.

C 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.

Which of the following are true about mid-ocean ridges? (Select all that apply.) A. a site of deep earthquakes B. the equivalent of a subduction zone C. the site of the production of oceanic crust D. becomes progressively younger toward Iceland E. has abundant extensional normal faults

C & E Mid-ocean ridges are a type of divergent plate boundary. Here oceanic crust is formed as two oceanic plates move away from one another, and upwelling mantle partially melts, then solidifies as basalt. This makes a thin layer of crust, and because it is thin, only shallow earthquakes occur here. Because they are divergent there are many extensional faults within mid-ocean ridges.

Which of these geologic features are not found on all of the following planets—Mercury, Mars, and Earth? (Choose all that apply) A. impact craters B. tectonic landforms C. sand dunes D. volcanoes E. river valleys

C & E 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.

PHOTO - These images show 5 stages in Earth's 4.6 billion year evolution. Using the drop downs below, sort the images from youngest at the top, to oldest at the bottom.

C, E, A, D, B Earth started off forming a primitive crust that was pelted by many impacts (B). Subsequently, small nuclei of continents began to form (D). These nuclei began to grow into large continents with a granitic composition and plate tectonics began (A). These continents collided and attached to one another to form the super continent known as Pangea (E). Ultimately, Pangea broke up, dispersing the continents and placing them in the locations we see today (C).

PHOTO - What is the probable origin of the features shown in this image of the surface of Mars? A. Glaciers of flowing ice shaped this landscape. B. Volcanic processes shaped these landforms. C. These are dendritic channels eroded by liquid water. D. These features are dunes shaped by the wind. E. This is part of the polar ice cap of Mars. F. Sublimation of ground ice caused collapse of the surface G. vast floods of water caused these outflow channels

D

Which "planet's" interior stayed warm longer? A.Vesta B. the Moon C. Mercury D. Mars

D

PHOTO - Which of the letters on this cross section of Earth labels where the silicic continental crust is made?

D Continental crust is made at convergent plate boundaries. Where the under riding plate induces partial melting of the mantle wedge, creating magmas with andesitic to rhyolitic compositions.

Karst topography is produced _______________. A. by glacial melt waters B. because rocks behave differently at high pressure C. because groundwater is abundant in tropical climes D. because limestone is relatively soluble in water E. by collapse of the roofs of lava tubes

D Karsts form by ground water dissolving limestones, since limestones are soluable.

PHOTO - Which of the letters on this shaded relief map is a convergent plate boundary?

D Oceanic crust juxtaposed to continental crust always marks a convergent plate boundary.

Which of the following is not usually associated with a terrestrial subduction zone? A. a trench B. one lithospheric plate moving under another C. andesite—rhyolite volcanism and stratovolcanoes D. basaltic shield volcanoes

D Subduction zones are located where two plates are colliding (converging) together. The more denser of the two plates will move underneath the less dense plate, and this location is usually marked by a trench. The lower trench will induce partial melting of the mantle wedge, creating magmas with compositions between andesite and rhyolite. However, this tectonic process never produces basaltic shield volcanoes.

Which gas was most efficiently removed from the Earth's atmosphere since the advent of life? A. Oxygen—O2 B. Helium—He C. Nitrogen—N2 D. Carbon Dioxide—CO2 E. Water—H2O

D The first forms of life on Earth were single-celled organisms that breathed in carbon dioxide, by photosynthesis, and produced free oxygen.

Radar images of Venus show all of the following except __________. A. mountain chains B. volcanoes C. rift valleys D. plains E. river valleys

E Radar images do not show any dendritic valleys nor any evidence for liquid water on Venus.

PHOTO - Which of the letters on this shaded relief map is a divergent plate boundary?

C Divergent plate boundaries often occur in oceanic crust and produce grabens and normal faults.

PHOTO - 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. Which of the images is of crater on the Moon?

B

PHOTO - Study these radar images of impact craters on Venus. Arrange their letters from smallest to largest.

Smallest B A D C Largest Small craters are irregular and occur in clusters. With progressively larger craters have terraces, central peaks, and peak rings, and the largest are multiring basins

PHOTO - Which letter is on a young volcanic plain in this colore shaded relief map along Mars Great Escarpment?

A Low viscosity, basaltic lava flows smooth out surfaces on planets by filling in cracks and craters and usually contain abundant wrinkle ridges.

Although both Mercury and Mars have similar gravity fields, Mars has an atmosphere whereas Mercury does not. What is a possible explanation? A. Mars is more volatile rich. B. Mercury's volatiles are frozen at its poles to form ice caps. C. Mercury has no volcanic activity but Mars has many volcanoes that belched gases to the surface. D. Because there was life on Mars that released gas to form the atmosphere.

A 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.

In what way is the history of Earth similar to the history of the Moon? A. Both "planets" once had heavily cratered surfaces. B. Both eventually developed plate tectonics. C. Both once had thick atmospheres of carbon dioxide and nitrogen. D. Both have magnetic fields to this day, shaped by convection of molten iron cores.

A Earth once had a heavily cratered surface, just like the Moon has today. None of the other answers have occurred on the Moon. The Moon did not develop plate tectonics, and is volatile poor not allowing an atmosphere to develop, nor does the Moon have a magnetic field or convection in a molten iron core; in fact the Moon may not even have a core.

The Earth's oceanic crust is composed mostly of ____________________. A. igneous rocks of basaltic composition B. shales and lamiestones C. accumulations of salt deposited from sea water D. granite plutons formed at the mid-ocean ridge

A Earth's oceanic crust is formed at divergent plate boundaries. Here upwelling mantle partially melts and is extruded through fissures and creates the oceanic crust. The rocks that form by this process are basaltic in composition.

Why is the history of Venus so different from that of Mars? A. Venus is significantly larger than Mars and cooled slowly. B. Venus is smaller than Mars and cooled more quickly. C. Venus lacks multiple impact craters because it is so far from the asteroid belt.

A 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? A. Carbonate minerals may have formed in the water and removed the carbon dioxide from the atmosphere. B. The high sulfur content of the atmosphere may have made the water acidic promoting extensive weathering. C. The greenhouse effect may have been even more intense.

A 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.

Would you be surprised if tomorrow's newspaper reported that a volcano was discovered erupting on Mercury? A. Yes, that is not expected to happen on Mercury today. B. No, Mercury is so hot because it is near the Sun that this would be expected. C. No, Mercury has such a large iron core that it has cooled very slowly and could still have volcanoes erupt on its surface. D. No, the tidal heating from the nearby Sun keeps it volcanically active.

A Mercury no longer has volcanic activity because its lithosphere is too thick for magmas to penetrate.

The largest dune fields on Mars are ____________________. A. in the polar regions B. in the equatorial canyons C. at the base of Olympus Mons D. in Hellas Basin

A See Sections 6.7.4 Polar Regions: Ice and Wind and 6.8.2 DunesLinks to an external site. The largest dune fields are seen in the polar regions of Mars. See figure 6.24.

Mercury's smooth plains ____________________. A. may be similar in origin to the lunar maria B. are cut by large grabens or linear rilles C. are older than Caloris basin D. are probably thick deposits of dust

A The smooth plains have few craters compared to the heavily cratered terrain and resemble the lunar maria.

Which of the following is a major difference between Venus and Earth? A. atmospheric composition B. mass C. volume D. density E. gravity

A Though the size, density, gravity, and volume are near identical between the 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' atmosphere is almost all carbon dioxide.

PHOTO - Examine this image of Mars carefully. Which feature is a small shield volcano?

A Volcanic shields are low relief volcanoes that are reminiscent of Greek shields. These volcanoes are produced by low viscosity lava that cannot build up much topography.

What is the probable origin of the smooth plains in the Northern Hemisphere of Mars? Choose all that apply. A. The depression probably started to form as a giant impact crater that covered half of the planet. B. The elevated highland started to form above a rising mantle plume and volcanic eruptions buried it. C. Sediment from a series of temporary seas smoothed it out. D. The crust in this region became so thick that it started to subside into the mantle. E. Eolian erosion carved the basin.

A & C

Which of the following tectonic processes are thought to have occurred on Mercury? (Check all that apply) A. thrust faulting due to contraction of the planet B. thrust faulting due to expansion of the planet as it heated C. graben formation due to contraction D. graben formation due to extension

A & D Both extensional and contractional tectonics have occurred on Mercury. Extension produces grabens while contraction produces thrust faults. It is important to remember extension cannot produce thrust faults nor contraction produce grabens.

A weak layer within Earth which behaves like a viscous fluid is _________________. (Mark all that apply.) A. the outer core B. the crust C. the lithosphere D. the asthenosphere E. the inner core

A & D There are two layers within the Earth that behave like a viscous fluid: the asthenosphere (which is partially molten because it is near its melting temperature) and the outer core which is totally liquid. The crust, lithosphere, and inner core are all solid (as evidenced by seismic waves).

Click on the possible explanations for Mercury's large core. Choose the two most likely. A. Mercury formed near the Sun in a zone that was oxygen-poor and rich in metallic iron. B. Mercury's magnetic field collected large masses of iron during accretion. C. During its early accretion, a large iron asteroid collided with Mercury and the iron sank to its core. D. A large impact stripped away the silicate shell from an already differentiated Mercury.

A & D There are two main theories as to why Mercury has such a large iron core. The first is, Mercury accreted in a 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.

Conditions on Venus are such that which of the following are true? Choose all that apply. A. Pure lead would be a liquid on its surface. B. Most of the CO2 is trapped in carbonate rocks (limestone). C. Precipitation of water as rain occasionally occurs. D. Sulfuric acid drips from the sky to cause intense weathering of rocks on the surface. E. The pressure is about 90 times that on Earth.

A & E 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.

Which of these factors control the Earth's hydrologic system? (Mark all that apply.) A. gravity B. solar energy C. topography D. temperature

A, B, C & D (all of the above) 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.

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.) A. Using energy from the Sun, organisms consumed carbon dioxide and released oxygen into the atmosphere. B. The oxygen produced by living things oxidized (weathered) the minerals and rocks at the surface. C. The evolution of creatures that make shells of calcium carbonate helped remove carbon dioxide from the atmosphere. D. Large quantities of dissolved iron were removed from the ovean to form delicately banded iron-rich sediments.

A, B, C & D (all of the above) The advent of life effected Earth in many ways. Life released free oxygen into the atmosphere and consumed carbon dioxide by the process of photosynthesis. This free oxygen has (and continues) to oxidize the rocks and minerals on the surface. removed carbon dioxide from the atmosphere by breathing and creating shells of calcium carbonate, this allowed Earth to have a moderate surface temperature in opposition to Venus. Oxidizing of iron in the ocean removed the iron from the ocean by causing the precipitation of banded iron-rich sediments.

Mars and Mercury differ substantially in what way(s)? Choose all that apply. A. The compositions of their atmospheres. B. Their densitites. C. The sizes of their cores. D. Their surface temperatures. E. The strength of their gravity fields.

A, B, C, D (not E) Notes: Mercury way more dense (2nd most dense), mercury no atmosphere, mercury much larger core, Mercury has extremes while Mars is freezing. Gravity field the same (mars has none and mercury has some) 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.

How many meteorite impact craters have been identified on Earth? A. About 10 B. About 100 C. About 1,000 D. About 10,000 E. About 100,000

B

What is the most important factor in the volcanic and tectonic evolution of Venus as compared to Mars? A. The distance Venus is from the Sun which elevates its surface temperature and makes its lithosphere thin. B. The size of Venus which makes it cool slower than Mars. C. The composition of Venus with higher concentrations of radioactive elements like potassium, uranium, and thorium.

B 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.

What causes the important differences between craters on the Moon and those on Mercury (the extent of the ejecta blanket and secondary cratering)? A. differences in the cratering rate B. different gravitational attractions on each planet C. crustal deformation D. the size of the meteorites impacting Mercury

B Gravitational pull can effect the extent of crater ejecta and secondary craters. Both of these features will extend for greater distances on planetary bodies that have less gravity

The oldest types of terrains on both the Moon and Mercury are ________________________. A. smooth, flood lava plains B. heavily cratered terrain C. folded mountain belts D. characterized by sinuous rilles and linear rilles

B Heavily cratered terrain is older than terrain with less craters, since cratering rate has decreased with time.

What is the Tharsis "bulge"? A. The elevated part of the polar ice cap of Mars. B. A large dome that was associated with the development of an extensive fracture system. C. The result of rebound in an impact basin. D. Weight gain associated with middle age. E. A large region elevated by crustal contraction when Mars was young.

B Multiple, large volcanoes sit a top the Tharsis "bugle". This bulge is associated with fractures that radiate away from the bulge. The presence of large volcanoes is evidence for an ancient mantle plume that may have risen in this location, lifting the crust and producing volcanism.

The outflow channels on Mars are different from river systems on Earth in what way? A. they lack extensive transport sytems B. they appear to come from below the surface and lack extensive collection systems C. they are proportionally smaller D. they are more sinuous E. they show numerous flow features

B The lack of smaller tributaries connected with the large outflow channels suggest water did not flow from other places into a larger channel. Instead, the outlfow 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.

How thick is Earth's lithosphere? A. Less than about 10 km thick. B. Between about 10 and 200 km thick. C. Between about 200 and 1000 km thick. D. Thicker than the Moon's lithosphere.

B The lithosphere is the solid, outer shell of the Earth. It includes the crust and the solid mantle that is above the asthenosphere. It ranges in thickness from ~10 km at mid ocean ridges to 200 km below convergent continental margins.

PHOTO - What is the most likely cause of the sinuous feature that extends across this radar image of Venus? A. Erosion by running water. B. Erosion by hot flowing magma. C. Erosion by hot, near-surface winds. D. Thrust faulting. E Extensional faulting.

B 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.

PHOTO - Select the letter of the area of this radar image of Venus that has been shaped by Eolian processes.

B Wind can produce a variety of features, including streaks, which are labelled as B. The others are tectonic or volcanic features.

PHOTO - 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. A. iscous lava flow B. Low viscosity lava flow C. Basaltic lava flow D. Landslide tongue E. Silicic lava flow F. Glacier

B & C 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.

PHOTO - Study this colored topographic map of Venus and identify the following provinces using the letters on the map. - highland - upland - lowland

B - highland C - upland A - lowland The uplands are large plateaus and encompass large areas (red) 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

PHOTO - What is the probable origin of the features shown in this image of the surface of Mars? A. Glaciers of flowing ice shaped this landscape. B. Volcanic processes shaped these landforms. C. These are dendritic channels eroded by liquid water. D. Vast floods of water caused these outflow channels. E. Sublimation of ground ice caused collapse of the surface. F. This is a dune shaped by the wind. G. This is part of the polar ice cap of Mars.

C

The two large volcanoes of Venus, Theia Mons and Rhea Mons, lie on the flanks of a structure similar to which of the following? A. A subduction zone like the one that formed Andes Mountains of South America. B. A volcanic chain over a "hot spot" like Hawaii. C. The East African Rift valley. D. An island arch such as Japan.

C Devana Chasma is an extenisonal 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.

PHOTO - How did these vast valleys on Mars form? A. The wide valleys formed as flood lavas crossed the surface. B. The valleys were carved by winds blowing off the Tharsis rise. C. The outflow valleys were eroded by liquid water. D. The valleys formed as glaciers eroded the landscape but then melted away.

C Flowing water erodes the landscape and produces sinuous stream channels that flow from higher elevation (left) to lower elevation (right). Look at the images within this section as well to get a feel for what outlfow channels look like especially figure 6.2a.

PHOTO - Which of the letters on this cross section of Earth labels where the mafic ocean crust is made?

C Mafic oceanic crust is made at mid-ocean ridges, where upwelling mantle partially melts and the magma is erupted through a fissure.

Why does Mars lack a well-integrated hydrologic system? A. It is poor in water. B. It is too hot. C. It is too cold. D. It never differentiated.

C 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 the following are major extensional features on Venus? A. The wide belts of ridges on the lowlands. B. The continental highland known as Ishtar Terra. C. Rift valleys and grabens associated with lithospheric domes.

C Rift valleys and grabens form by extension. While ridge belts are contractional and Isthar Terra is also contractional.

What do thermal models of Mercury's evolution suggest about its history? A. That it has developed a core in the last billion years or so. B. That it experienced global expansion to produce domical bulges. C. That it developed a metallic core early in its history. D. That its history is more like the Earth's than the Moon's.

C See Section 5.9 Geologic Evolution of MercuryLinks to an external site. and pay attention to figure 5.31 The iron within Mercury separated out into a core early in the planet's history.

Considering the ways it forms, deforms, and crystallizes, glacial ice can be considered to be which of the following? A. regolith B. an igneous rock C. a metamorphic rock D. a sedimentary rock

C Since the ice in glaciers deforms and recrystallizes without melting it is similar to metamorphic rocks. Unlike igneous rocks that come from melt or sedimentary (which come from fragments of previously eroded rocks) or regolith (dust)

Large amounts of water (as gas or liquid) on Venus _________. A. lie in shallow oceans near its cool polar regions. B. probably never existed C. have probably been lost to space and by combination with surface materials. D. exist beneath the surface in shallow aquifers.

C 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.

Which of the following statements are accurate descriptions of the atmosphere of Venus? A. It is cold and dry. B. It is the densest of all the planets. C. The Venusian atmosphere is rich in carbon dioxide. D. It is an inherited remnant of the gaseous solar nebula. E. It has abundant water vapor.

C The composition of the Venusian atmosphere is ~96% carbon dioxide. It is a secondary atmosphere that formed by 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' 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.

Impact craters on Venus that are larger than about 30 km in diameter are __________. A. rare because of the planet's dense atmosphere B. abundant on the cratered highland of Ishtar Terra C. not common because of the plante's dynamic interior and young surface D. not visible because of the low resolution of current images

C The surface of Venus is too young to have large craters. They would have been destroyed.

Folded mountain belts are important tectonic landforms. Which of the following statements is the most accurate description of folded mountain belts? A. They are found on all of the terrestrial planets. B. They are dominated by normal faults and grabens. C. They are found around the margins of highlands on Earth and Venus. D. They are produced by impact compression of thin lithospheres.

C 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.

Which features of Mars indicate a distinctive geologic process that doesn't operate on Mercury or the Moon? A. Linear rilles caused by tectonic activity. B. Volcanic plains and volcanoes. C. Wrinkle ridges caused by tectonic processes. D. Domal upwarps of the lithosphere and associated fractures caused by mantle plumes.

D Formation of lithospheric domes but rising mantle plumes are not seen on the Moon or Mercury, while Mars has several.

Where are the oldest rocks on Earth found? A. At points farthest from an ocean ridge. B. At points farthest from a subduction zone. C. In Hawaii. D. In its continental shields.

D The oldest rocks on Earth are found on continental shields because they are not disturbed in this location. At the fartherest point from a mid-ocean ridge, the plate is subducting and being destroyed. And vice versa, at the farthest point from a subduction zone the rocks are being created at a mid-ocean ridge, therefore they are young. Hawaii has rocks being created right now, so most of them are very young.

The presence of oxygen (O2) in a planet's atmosphere is strong evidence for ___________________. A. an ancient surface B. a young surface C. loss of CO2 to space D. the presence of living organisms E. the T-Tauri stage in the Sun's evolution

D The only process we know of that produces free oxygen is photosynthesis.

Which planetary body has (basically) no magnetic field today? A. Earth B. Jupiter C. Mercury D. Mars

D 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.

What are some of the main reasons Venus and Earth have such different histories? A. Venus is a much smaller planet so it cooled more quickly than Earth and preserves heavily cratered terrain. B. Because Venus is so close to the Sun, the atmosphere of Venus was blown away during the T-Tauri stage of the Sun's evolution, but Earth was able to keep one. C. The giant Chicxulub impact heated Earth dramatically and started plate tectonics, but Venus has not had any large young impacts. D. Venus was hot enough that liquid water never precipitated on its surface to make oceans.

D Venus and Earth have different histories because the Earth developed oceans while Venus was too hot for liquid eater to precipitate. We know that Venus and Earth are nearly identical in size, which suggests they are cooling at about the same rate and so both will have active volcanism and tectonism to create a young surface. Venus has such a thick atmosphere of carbon dioxide we cannot see to the surface, so we know the T-Tauri state of the Sun did not blow away the atmosphere. While we may not know exactly why plate tectonics began on Earth and not on Venus, we know a giant impact could not have initiated it because all terrestrial bodies have experienced large impacts.

Martian valley networks are ____________________________________. A. related to the development of highland volcanic centers B. related to huge catastrophic floods C. developed by wind erosion D. restricted in occurrence to the oldest parts of Mars

D Water flows from higher to lower elevation. This means, on Mars, the water channels will flow from the southern highlands to the northern lowlands.

What explains the number of impact craters that have been identified on Earth? (Select all that apply.) A. Earth is so large that it has many meteorite impact craters on the surface. B. Earth formed 4.6 billion years ago and so it has accumulated many impact craters on its surface. C. Earth has only a few impact craters because it is shielded heavily by the Moon. D. Earth has few impact craters because its ancient surface has been extensively modified by erosional processes. E. Earth has few impact craters because many were obliterated by subduction, mountain building, and volcanism.

D & E

PHOTO - What is the probable origin of the features shown in this image of the surface of Mars? A. This is a dune shaped by the wind. B. These are dendritic channels eroded by liquid water. C. Volcanic processes shaped these landforms. D. This is part of the polar ice cap of Mars. E. Sublimation of ground ice caused collapse of the surface. F. Glaciers of flowing ice shaped this landscape. G. Vast floods of water caused these outflow channels.

E

PHOTO - These diagrams show the history of Mars but they are not in the correct chronologic order. Put the events into the proper order with oldest first in your list and the youngest last in your list.

Oldest A, D, F, B, E, C youngest