Concept Inventory

Question 1. Four layers of sedimentary rock are shown in the cross-section diagram. Which layer is oldest?  
http://commons.wvc.edu/rdawes/GEOL101/strat1.gif Links to an external site.

a. A 

b. B 

c. C 

d. D 

e. There is not enough information in the diagram to tell. 

 

2. Three layers of sedimentary rock and one of igneous rock are shown in the cross-section diagram. Which layer of rock is youngest?
http://commons.wvc.edu/rdawes/GEOL101/strat2.gif Links to an external site.

a. A 

b. B 

c. C 

d. D 

e. There is not enough information in the diagram to tell. 

 

3. A layer of conglomerate is on top of a large body of granite (see cross-section diagram). There are rounded pebbles of granite in the conglomerate. (Conglomerate is sedimentary rock made of gravel that was buried, compacted, and cemented into rock by natural processes.) Which rock is older, the conglomerate or the granite?

a. The conglomerate is older 

b. The granite is older 

c. They must be the same age 

d. There is not enough information to tell. 

 

4. A layer of conglomerate is on top of a large body of granite (see cross-section diagram). There are angular pieces of conglomerate within the granite. Which rock is older, the conglomerate or the granite?

a. The conglomerate is older 

b. The granite is older 

c. They must be the same age 

d. There is not enough information to tell 

 

5. The cross-section below shows some rocks and geologic structures as seen in the face of a vertical cliff. Going from oldest to youngest, what is the correct relative age sequence?

a. A, B, C, D, E, F, G 

b. F, G, E, B, C, A, B 

c. D, G, E, F, A, C, B 

d. D, G, E, B, F, A, C 

e. D, G, A, C, E, F, B 

 

 

6. A radioactive isotope is measured to determine its half-life. After 10 days of analysis of a carefully measured sample of the isotope with a Geiger counter, it is found that 1% of the isotope atoms have decayed. This measurement indicates that the half-life of the isotope: 

a. Is 1000 days. 

b. Is 10 days. 

c. Is more than 1000 days. 

d. Has a value that can be calculated using the data from the experiment plugged into the appropriate equation for exponential decay. 

e. Both c and d are true. 

 

7. Potassium-40 has a half-life of 1.3 billion years. In a granite with crystals of potassium feldspar, the feldspar was analyzed and it was found that 7/8 of the original amount of potassium-40 had decayed. How old is the granite? 

a. 0.33 billion years 

b. 2.6 billion years 

c. 3.9 billion years 

d. 0.65 billion years 

e. Older than whatever rock is on top of the granite. 

 

8. Accumulation of clay in the deep ocean, far from any continent, was measured in several spots and found to average 0.1 mm/year, with little variation. A body of rock made of many layers of clay, with deep-ocean fossils, was found to be 250 m thick (one m = 1000 mm). If you divide 250 m by 0.1 mm (after converting to common units), the result is 2,500,000. From this which of the following can be concluded? 

a. The earth is no more than 2,500,000 years old. 

b. The body of rock accumulated in no more than 2,500,000 years. 

c. The body of rock is made of layers of sediment that may have taken about 2,500,000 years to accumulate. 

d. The body of rock probably represents at least 2,500,000 years of sediment accumulation. 

e. There is not enough information to form a conclusion. 

 

9. Plate tectonics is the idea that: 

a. The earth's crust is broken into plates that move around on top of the liquid mantle. 

b. The earth's crust is broken into plates that move around on top of the soft, solid upper mantle. 

c. The earth's crust is broken into plates that move around on top of the soft lithosphere. 

d. All the continents were once joined together as the super-continent Pangaea. 

e. Earthquakes and volcanoes are all caused by plates colliding. 

 

10. Which of the following lines of evidence supports plate tectonics? 

a. Magnetism of rocks that allows measurement of the movement of the rocks across the face of the Earth since they first formed. 

b. Patterns of earthquakes, including depths of earthquakes, which provide three-dimensional views of plates moving alongside or colliding into one another. In addition, patterns of volcanic eruptions, which are consistent with where plates are tearing apart from each other and where they are colliding. 

c. The shape of continents on either side of the Atlantic Ocean, which fit together almost exactly, like pieces of a jig-saw puzzle. In addition, the fossil record is consistent with when the continents would have been joined together and when they drifted apart. 

d. Satellite-based precision measurements of positions of points on the continents (GPS measurements), which shows them moving as predicted by plate tectonic theory. 

e. All of the above. 

 

11. The Pacific Northwest coast is at which specific type of plate boundary? 

a. convergent: oceanic crust - continental crust 

b. convergent: oceanic crust - oceanic crust 

c. convergent: continental crust - continental crust 

d. transform fault 

e. divergent plate boundary 

 

12. The idea that California will "fall into the sea" during a cataclysmic earthquake is based on: 

a. plate tectonic theory 

b. the elastic rebound theory of earthquakes 

c. extrapolation of current trends of plate motions 

d. all of the above 

e. a non-scientific source with no scientific validity 

 

13. Because of the location of north central Washington relative to plate tectonic activity, the region is at what sort of risk from earthquakes and volcanoes?

a. virtually no risk from the effects of earthquakes or volcanic eruptions 

b. moderate risk from the effects of earthquakes or volcanic eruptions 

c. extreme risk from the effects of earthquakes or volcanic eruptions 

d. moderate risk of earthquake effects but no risk of volcanic eruptions 

e. unknown risk of volcanoes and earthquakes 

 

14.       In science, a mineral is defined as: 

a. something that is not animal or vegetable 

b. something that is solid and hard 

c. an inorganic solid made of a symmetric lattice of bonded atoms 

d. a solid that in aggregate composes rocks 

e. -there is no agreed-upon definition 

 

15. Which of the following is not made of minerals? 

a. granite 

b. basalt 

c. ice 

d. obsidian (volcanic glass) 

e. limestone 

 

16. Which of the following factors do not affect which minerals will naturally form? 

a. the presence of specific chemical elements 

b. geologic period 

c. solid pressure 

d. gas pressure 

e. temperature 

 

17. For hot rocks inside the Earth, which of the following is NOT likely to cause the rocks to start melting? 

a. increased pressure 

b. increased temperature 

c. addition of water 

d. decreased pressure 

e. upwelling (uplift of the rocks towards Earth's surface) 

 

18. Which of the following is NOT a common trigger of volcanic eruptions? 

a. earthquake 

b. dissolved volatiles (gas inside molten rock) 

c. water turning to steam 

d. decreased pressure on molten rock beneath Earth's surface 

e. input of a new batch of hot, molten rock beneath a volcano 

 

19. For sediment such as sand to be turned into sedimentary rock, what generally happens to the sediment? 

a. It is struck by lightning 

b. It is infiltrated by rainwater (or melted snow) and gets cemented together by precipitated minerals 

c. It goes down a subduction zone and is melted, then solidifies into solid rock 

d. It is buried deep enough to be compacted and naturally cemented together 

e. It is erupted from a volcano 

 

20. Where does sediment on the Earth come from? 

a. mainly from meteorites 

b. mainly from humans digging up the dirt 

c. from explosive volcanic eruptions 

d. from wind and water 

e. from solid rocks, which get turned into sediment by weathering and erosion 

 

21. What is the root meaning of "metamorphism"? 

a. multiplication of a basic form 

b. corruption 

c. change of form 

d. completion of final stage of growth 

e. melting and recrystallization 

 

22. If a major earthquake occurs in your vicinity, then by how much the ground moves and the type of damage it does to buildings and other structures, you can estimate: 

a. what particular type of earthquake it was 

b. the magnitude of the earthquake 

c. how far away the earthquake was 

d. how deep in the ground the earthquake was 

e. the intensity of the earthquake 

 

23. If you are in a brick building that is suddenly struck by a major earthquake, then the safest thing to do is: 

a. do not move; brick buildings are the one type of structure that withstands earthquakes 

b. get outside 

c. get under a desk or doorway 

d. call for help on a cell phone 

e. get into the basement 

 

24. Earthquakes can be predicted in terms of: 

a. where the next one will occur 

b. when they occur, down to the day 

c. when they occur, down to the month 

d. when they occur, but only down to the year 

e. the odds of one occurring in the next year in a given area 

 

25. When an earthquake occurs, what happens to the rocks that moved along the fault? 

a. They go back to their previous position along the fault. 

b. They are broken into rubble. 

c. On each side of the fault, the rocks recover most of their original shape, but along the fault the rocks will have shifted relative to the other side of the fault. 

d. They melt and recrystallize into metamorphic rock. 

e. They develop an electrical charge that could create lightning in the air above the fault zone. 

 

26. Compared to the crust, the mantle is: 

a. made of iron and other metals, more basic than the silicate minerals of the crust 

b. mostly liquid, in contrast to the solid crust 

c. less dense (which makes it prone to erupt through the crust) 

d. more dense (which keeps it beneath the crust) 

e. cooler  

 

27. The Earth's core is known to be made largely of iron because: 

a. Pieces of the core expelled in volcanic eruptions are made of iron. 

b. It is the only way to account for a wide variety of known properties. 

c. Pieces of the core brought to the surface along fault zones are made of iron. 

d. Drilling by the Soviet Union in the 1970s penetrated the core and showed that it is made of iron. 

e. The core must be essentially a bar magnet to account for the Earth's magnetic field, and iron is the only common magnetic element. 

 

28. Unlike the Moon and the planet Mercury, Earth does not have a surface extensively scarred by meteorite craters. What is this a result of?

a. The Earth is younger and did not exist during the stage of intensive meteorite bombardment early in the history of the solar system. 

b. The Earth is larger, so it has retained more internal heat that drives geological renewal of its surface, and has retained an atmosphere that drives weathering and erosion of its surface. 

c. The Earth is extensively covered by oceans. 

d. The Earth has an atmosphere, which burns up most meteors (by frictional heating) before they can reach the surface. 

e. The gravity of the Moon expels most large meteors from the vicinity of Earth. 

 

29. On a magnetic compass, the North arrow points: 

a. to the Earth's geographic North Pole. 

b. to the Earth's magnetic North Pole. 

c. to the Earth's geographic South Pole. 

d. to the Earth's magnetic South Pole. 

e. to the local magnetic inclination, which varies from place to place. 

 

30. The Earth's magnetic field: 

a. is constant and unchanging. 

b. is constant and unchanging in modern history, but geological evidence suggests it once wandered and even reversed itself. 

c. wanders a few miles and changes strength on a year-by-year basis, and in the past has undergone reversals of its north and south magnetic poles 

d. varies with the intensity of the solar wind 

e. does not really exist; it is a pseudo-field caused by the Earth's rotation in the solar magnetic field 

 

31. Waterfalls are: 

a. part of an equilibrated stream system 

b. the source of most power in streams 

c. where most stream erosion occurs 

d. a temporary aberration of a stream profile which, given enough time, will be eroded away and smoothed out 

e. a normal part of stream development, which, by undermining and landsliding, will move downstream and become less steep 

 

32. As seen on a map, most tributaries join main streams at an angle that: 

a. points in the downstream direction 

b. is usually more than 90° 

c. is usually less than than 90° 

d. increases in the downstream direction 

e. is actually random when analyzed statistically 

 

33. Most valleys on Earth are: 

a. the result of faults 

b. the result of volcanic processes 

c. the result of erosion by streams 

d. the result of erosion by wind 

e. of unknown origin 

 

34. Floods on rivers are: 

a. unusual and unpredictable 

b. normal and predictable 

c. common only in high-rainfall climates 

d. the result of sudden thunderstorms with heavy short-term rainfall 

e. less common now than in the recent past, due to recent climate change 

 

35. Groundwater moves inside the Earth mainly through: 

a. caverns and caves 

b. thermal pressure gradients created by volcanic heat 

c. going down subduction zones and coming out in volcanic outgassing 

d. slowly percolating through tiny spaces and cracks in rocks 

e. changing phases, from ice to liquid to steam 

 

36. Many cities along the Columbia River, including Wenatchee and East Wenatchee, get their municipal water supply from: 

a. wells (from an aquifer of groundwater) 

b. the Columbia River (it is then filtered and purified) 

c. reservoirs on local stream drainages into which Columbia River water is pumped 

d. catching and storing rainwater 

e. local tributaries of the Columbia River (which have cleaner, faster-flowing water than the impounded Columbia River does) 

 

37. In much of the High Plains (an agriculturally rich zone that includes much of north Texas, Oklahoma, Kansas, Nebraska, South Dakota, and eastern parts of Colorado and Wyoming), where does most water for irrigation of crops come from? 

a. the rivers of the area, which flow down from the Rocky Mountains 

b. the High Plains Aquifer (also called the Ogallala Aquifer) 

c. local aquifers, which each farm or neighborhood of farms locates and taps 

d. the Mississippi River 

e. the Missouri River 

 

38. When Admiral Peary was the first to go to the North Pole, he and his companion mushed their dogsled across ice to reach the pole. Technically, this ice was: 

a. a glacier 

b. sea ice 

c. a leftover remnant of the "Little Ice Age," which has since melted 

d. a highly viscous liquid 

e. actually salt, consisting less than 50% of water 

 

39. What evidence is there that the Wenatchee area was glaciated during the most recent "ice age"? 

a. boulders dropped onto the local landscape by the moving glacier, which carried the boulders in from elsewhere (the boulders do not match the local bedrock) 

b. scratches and scrapes left on local bedrock by the moving glacier 

c. patches of glacial till in the area (glacial till is sediment carried and directly deposited by glacial ice) 

d. all of the above 

e. none; the Wenatchee area was not glaciated 

 

40. What was the source of the giant glacier that reached into parts of western and eastern Washington during the Pleistocene Epoch (during the most recent "ice age")? 

a. high mountains of the Cascades such as Mt. Rainier, which formed glaciers that flowed out and joined together into one large sheet in the lower areas adjacent to the mountains 

b. the North Pole region (north of Canada), from which continental ice sheets spread out not only into parts of western and eastern Washington, but most of Canada and other parts of northern states in the US, as well as northern Europe and Russia. 

c. the mountains of British Columbia and western Alberta, Canada 

d. local plateaus and highlands, including the Samish Plateau (western Washington) and the Okanogan Highlands (eastern Washington), where glacial ice formed due to high precipitation and low temperatures 

e. the only glaciers to reach into Washington State during the Pleistocene Epoch were confined to high valleys in the Cascade and Olympic Mountains, and originated on local high peaks 

 

41. The fact that "ice ages" have come and gone in the geological past means that: 

    recent climate change is probably entirely natural 

   the Earth is unlikely to go into another "ice age" in the future 

   we cannot test models of climate by looking at the geologic record 

   we can predict a warmer future based on ice age history 

   there are natural factors that can cause climate change 

 

42. Most fresh (unsalty) water on Earth is in the form of: 

a. glaciers, ice, and snow 

b. streams and rivers 

c. water vapor in the air 

d. groundwater 

e. lakes 

 

43. Which agent causes most erosion and movement of sediment on Earth? 

a. moving water (streams) 

b. moving ice (glaciers) 

c. moving air (wind)  

d. gravity (landslides) 

e. plate tectonics 

 

44. Alluvial fans occur: 

a. only in arid climates that are subject to flash floods 

b. wherever a high-gradient stream discharges onto a much flatter area 

c. where alluvium fans out in several directions 

d. where stream meanders get cut off during floods 

e. where ephemeral streams dry up 

 

45. Your body contains minerals such as apatite, which are built into the structure of your body and necessary for it to function. In Earth system terms, this is an example of: 

a. the lithosphere in the hydrosphere 

b. the atmosphere in the lithosphere 

c. the biosphere in the lithosphere 

d. the lithosphere in the biosphere 

e. the core in the crust 

 

46. Volcanoes, plate tectonics, and most earthquakes receive their energy from: 

a. plate tectonics 

b. gravity and tides 

c. the heat of friction 

d. heat from the interior of the Earth 

e. solar radiation 

 

47. Small planets and moons, such as Earth's moon and the planet Mercury, show no signs of volcanic activity or tectonics since long ago. This is because: 

a. they have no plate tectonics 

b. they are too far from the Sun to have enough heat 

c. they are too small to have retained much interior heat since long ago 

d. nobody knows 

e. their geologic activity was halted by gigantic meteorite impacts 

 

48. Rivers, storms, wind, erosion, and the biosphere receive most of their energy from 

a. plate tectonics. 

b. gravity and tides. 

c. the heat of friction.. 

d. heat from the interior of the Earth 

e. solar radiation. 

 

49. Natural systems tend to move toward: 

a. the center of the Earth 

b. the center of the Universe 

c. equilibrium 

d. chaos 

e. lower entropy 

 

50. Compared to physics and chemistry, geology is: 

a. not a true science, because it is based on clues of an unseen past 

b. a science in its own right, which applies physics and chemistry to understanding the history and dynamic of the Earth 

c. less exact 

d. a younger science 

e. not a true science, because its hypotheses cannot be tested