Student #:
Please answer each question on your scantron sheet. Circle each correct answer on your test sheet in case there is a problem with the scantron form. Hand in both your test sheet and scantron form.
1. Thorium that is found in marine shells predominantly forms from ________.
a. radioactive decay of Uranium
b. precipitates of Thorium weathered from terrestrial rocks
c. atmospheric Thorium
d. degassing of hot spots.
e. biological processes within the mollusks.
2. Why does it become progressively more difficult to assign numerical ages to ice sheet records with increasing depth of the core?
a. snowfall levels were less in the past and the layers are harder to discriminate.
b. compaction and ice flow cause smearing of annual layers.
c. there is no difference in ice layers with progressive depth changes.
d. it is difficult to get deep ice cores therefore they have never been measured.
e. all of the above are correct
3. Cosmogenic isotopes can be used to date the surface exposure age of a landform if one knows the isotopic decay rate, altitude and latitude scaling factors, chemistry of the rock, erosion rate and __________.
a. the time of day that the sample was collected.
b. density of the rock sample
c. the production rate of the cosmogenic isotope in the rock
d. climatic regime from which the sample was collected
e. all of the above are correct
4. What other dating methods are used to calibrate radiocarbon years to calendar years?
a. tree ring counting and the potassium argon dating of lava
b. tree rings and uranium thorium dating of corals
c. fission track dating of tephras and uraniuim thorium dating of corals
d. tree ring counting and varve counting
e. answers b and d are both correct
5. The Younger Dryas climatic cooling was likely initiated by ___________?
a. increased ice berg flux out of Davis Strait cooled North Atlantic
b. eccentricity effects 11,000 years ago
c. sunspot cycles
d. volcanic eruption
e. draining of glacial Lake Aggasiz through St. Lawrence River system placed a freshwater cap on the North Atlantic.
6. Isostatic uplift of the northern Great Lakes region will result in drainage to be diverted through ______.
a. the Davis Strait
b. the Hudson Bay.
c. the Mississippi River.
d. the Hudson River.
e. the MacKenzie River.
7. How would you reconcile a 50,000 year surface exposure age for the Vashon Till using 36Cl dating when you know that deglaciation occurred only ~15,000 years ago.
a. the surface of the boulder spalled during multiple forest fires
b. the boulder was moved by a logging operation
c. The boulder fell onto the surface of the ice from a nunatak and possesses a prior exposure age
d. the radiocarbon ages must all be incorrect.
e. all of the above are correct
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8. Soil development on the loess plateau region of China is more extensive during interglaciations because:
a) the winter monsoon is enhanced bringing increased moisture into Asia during the winter.
b) summer temperatures are cooler causing moisture to be retained in the soil.
c) the summer monsoon is enhanced bringing increased moisture into Asia during the summer.
d) uplift rates of the Himalaya Mountains is increased during unloading of the Tibetan ice sheet.
e) none af the above
9. Why do we not use the K-Ca system (potassium-calcium) for dating earth rocks?
a. Radioactive potassium does not decay to calcium.
b. Radiocative potassium mostly decays to argon.
c. Most of the calcium in earth rocks is naturally occurring and is not radiogenic.
d. Calcium atoms are large and cannot be measured in a mass spectrometer.
e. none of the above are correct
10. Why do we not find long varve sequences in Cascade lakes?
a. Deglaciation only occurred recently.
b. The relatively temperate climatic regime promotes bioturbation which would disturb rhythmite layers.
c. varves do not form in alpine settings
d. We do find long varve sequences in Cascade lakes; sometime greater than 12,000 layers.
e. none of the above are correct
11. According to the marine oxygen isotope record at least _______ glacial-interglacial have occurred during the past 2 million years.
a) 10
b) 23
c) 100
d) 1000
e) 100,000
12. Long ice core records (>150,000 yr) are most commonly dated using ____________.
a) radiocarbon
b) fission track
c) annual ice layers in the top and modeling ice flow for the bottom of the core
d) uranium-thorium
e) annual ice layers from the top to the bottom of the core
13. As CO2 content increases in the atmosphere:
a) the Earth's climate cools
b) the Earth's climate does not change
c) the Earth's climate warms
d) tropical regions of the Earth warm considerably more than polar
e) tropical regions of the Earth cool considerably more than polar
14. Lake levels were higher during the maxima of the last glaciation in Nevada and Utah because:
a) the Jet Stream (storm track) was displaced to the south by the Cordilleran and Laurentide ice sheets.
b) the Jet Stream (storm track) was displaced to the North by the Cordilleran and Laurentide ice sheets.
c) evaporation rates were lower during the last glaciation.
d) evaporation rates were higher during the last glaciation.
e) answers a and c are correct
15. To determine surface ocean water temperatures _________.
a) 18O/16O ratios of planktonic forams are measured
b) 18O/16O ratios of benthic forams are measured
c) the difference between 18O/16O ratios of planktonic and benthic forams are measured
d) 18O/16O ratios can tell you nothing about temperature
e) none of the above
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16. During the last glacial maximum (18,000 yr, ago) lake levels were higher in North Africa because:
a) the Finno-Scandinavian ice sheet displaced the jet stream to the south.
b) evaporation rates were lower.
c) the Nile River was dammed by mountain glaciers in Ethiopia
d) the lakes were being filled by subsurface meltwater streams originating from Europe.
e) High solar insolation in the Northern Hemisphere promoted greater monsoon effects in North Africa.
17. During glacial cycles 18O/16O ratios in Greenland ice core record ________.
a) decreases
b) increases
c) remains the same
d) depends on where the ice core is taken
e) are nonexistent
18. Changing 18O/16O ratios in the marine oxygen isotope record largely reflect changes in _______.
a) sea surface temperatures
b) deep ocean temperatures
c) global ice volume
d) respiration rates of foraminifera
e) precipitation rates
19. If the ELA of alpine glaciers in full-glacial time was 1000 m lower than modern alpine glaciers, what would be the expected change in average temperature for this region, providing precipitation remained constant and the environmental lapse rate decreased by 0.6 °C for every 100 m increase in elevation?
a) the temperature would have been 0.6 °C warmer
b) the temperature would have been 0.6 °C cooler
c) the temperature would have been 6 °C warmer
d) the temperature would have been 6 °C cooler
e) there would be no change in the temperature for this region.
20. Large proglacial lakes formed in the Puget lowland because:
a) the Jet Stream (storm track) was displaced to the south by the Cordilleran and Laurentide ice sheets.
b) the Jet Stream (storm track) was displaced to the North by the Cordilleran and Laurentide ice sheets.
c) evaporation rates were lower during the last glaciation.
d) the Puget Lobe blocked the outlet of north flowing streams
e) answers a and c are correct.
21. Why do we tend to get loess deposition during glaciations?
a) climate tends to be cool and arid over large regions of the world.
b) glacial abrasion by large ice sheets produces large quantities of silt.
c) wind velocities tend to be high because of large pressure gradients
d) all of the above answers are correct
e) none of the above answers are correct
22. Shells living off the coast of western North America would have radiocarbon ages that exceed their actual age because ______________.
a. the radiocarbon production rate has changed in the last century
b. carbon in the ocean is older because of upwelling of deep water
c. carbon in the ocean is younger but mollusks live for centuries
d. carbon in the ocean is the same age as atmospheric carbon
e. shell ages are actually younger than atmospheric carbon
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23. What effects does time have on soil development?
a. soils become redder
b. soils become finer
c. soil profiles become thicker
d. all of the above are correct
e. none of the above are correct
24. Past ELA's of glaciers can be calculated using:
a) their accumulation area ratio for a previously glaciated valleys
b) the median altitude of the cirque headwall and the terminal moraine
c) the highest altitude of a lateral moraine representing a particular glaciation
d) all of the above
e) none of the above
25. Tree ring records of dead wood can be correlated with one another by:
a) directly comparing ring widths
b) comparing ring width pattens
c) comparing the number of rings
d) radiocarbon dating
e) counting cambian cells
26. To determine temperature changes in the deep oceans basins _________ foraminifera are most useful.
a) benthic
b) planktonic
c) living
d) Icelandic
e) polar
27. To develop ice wedges subsurface temperature________.
a) will always be below freezing
b) will always be above freezing
c) will fluctuate between periods of freezing and thaw
d) will be below the geothermal gradient
e) will remain constant
Below is a diagram showing the typical isostatic uplift curve. Answer
questions 28-31 using this curve.
28. Restrained uplift is:
a) that part of the curve where isostatic uplift occurs while ice still covers a region
b) uplift that occurs after ice retreats from a region
c) uplift that will occur in the future
d) is always smaller than post-glacial uplift
e) uplift that occurs under the Earth's gravitational attraction
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29. Uplift that is occurring today in the Hudson's Bay region is described by
part _____ of the above curve.
a. restrained uplift
b. post-glacial uplift
c. residual uplift
d. eustatic uplift
e. tectonic uplift
30. The uplift that occurred in Seattle prior to the retreat of the ice is represented by part _______ of the above curve.
a. restrained uplift
b. post-glacial uplift
c. residual uplift
d. eustatic uplift
e. tectonic uplift
31. The fact that we find glacio-marine drift 10 m above present sea level on Whidbey Island is due to ________.
a. restrained uplift
b. post-glacial uplift
c. residual uplift
d. eustatic uplift
e. tectonic uplift
32. If eustatic (global) sea level rise is less than the rate of isostatic uplift for a previously glaciated region then _______.
a. relative sea level will be rising
b. relative sea level will be lowering
c. relative sea level will be constant
d. the land will be submerged
e. all coastlines will be submerged
33. What geologic event is believed to cause the return to abrupt cooling at the end of the last glaciation (also known as the Younger Dryas Oscillation) in Northern Europe?
a. Milankovich parameters
b. Catastrophic discharge of glacial Lake Aggasiz into the North Atlantic as the Laurentide Ice Sheet retreated
c. Catastrophic discharge of the Baltic Sea into the North Atlantic as the Fenno-Scandia Ice Sheet retreated
d. plate tectonics
e. major volcanic eruption in Northern Europe
34. ____________ foraminifera would best reflect changes in sea surface temperatures.
a. benthic
b. planktonic
c. polar
d. sub tropical
e. thermohaline
35. What factors control eustatic sea level changes?
a. build-up of continental ice sheets
b. sea floor spreading rate
c. local tectonic uplift
d. all of the above are correct
e. only answers a and b are correct
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To answer questions 36-40 use the three relative sea level curves
labeled A-C below.
36. Based on the relative sea level curves, which location do you think had thicker ice.
a. Ottawa Island
b. New York City
c. Delaware
d. you cannot tell the relative ice thickness from these curves
e. all the locations had the same thickness of ice
37. Which location do you think was in the peripheral bulge?
a. Ottawa Island
b. New York City
c. Delaware
d. the peripheral bulge was absent from all locations
e. the peripheral bulge passed through all locations during retreat of the ice.
38. Why do you think relative sea level was lowering in Ottawa between 18 and 9 ky (thousand years) ago?
a). there was no isostatic uplift
b. eustatic sea level was greater than isostatic uplift during this time interval.
c . isostatic uplift was greater than eustatic sea level rise during this time interval.
d. Ottawa was tectonically subsiding.
e. the global ice volume was increasing.
39. Based on the New York City diagram, how many meters below modern sea level would the land have been submerged at 18 k.y. ago (Assume eustatic sea level was 150 m lower than modern at that time)?
a. 15 m
b. 165 m
c. 800 m
d. 400 m
e. 0 m
40. Based on the Ottawa Island diagram, how many meters below modern sea level would the land have been depressed 18 ky ago? (Assume eustatic sea level was about 150 m lower than present sea level).
a. 700 m
b. 550 m
c. 120 m
d. 250 m
e. 0 m
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41. The Laurentice Ice Sheet is believed to have catastrophically down wasted by:
a. rapid surface melting with increasing solar insolation
b. calving into marine embayments
c. surging
d. subsurface flow
e. none of the above
42. In order to use TL dating to assign numerical ages to the loess record __________.
a. you must determine the natural TL content of the sediment
b. you must determine the equivalent dose rate for the sediment
c. you must measure the radioactivity of sediment
d. all of the above are correct
e. only answers a and b are correct
43. Chlorine-36 dating allows geologists to date ____________.
a. the age of rock crystallization
b. the age of chlorine in salt domes
c. the age of rain water
d. the age of exposure of a landform
e. all of the above
44. Chlorine-36 is produced in terrestrial surface rocks by:
a. spallation of calcium atoms
b. spallation of potassium atoms
c. adding a neutron to chlorine-35
d. all of the above are correct
e. none of the above
45. Heinrich events are likely caused from ________________.
a. increasing atmospheric CO2.
b. surges and rapid calving of the Laurentide Ice Sheet
c. sunspot cycles
d. precessional effects of the earth's orbit
e. none of the above
46. What percentage of a glacier's total area comprises its accumulation zone?
a) 50%
b) 10%
c) 35%
d. 80%
e. 65%
47. To date a volcanic tephra using the fission track dating method you must _______________.
a) know the number of fission tracks/unit area
b) determine the length of each fission track
c) know the initial uranium content of the sample
d) all of the above are correct
e) only a and c are correct
48. Which Milankovich parameters are most conducive to ice sheet buid up in the northern Hemisphere?
a. high eccentricity, perihelion occurring in northern hemisphere summer, low obliquity
b. low eccentricity, perihelion occurring in northern hemisphere summer, low obliquity
c. high eccentricity, perihelion occurring in northern hemisphere winter, low obliquity
d. low eccentricity, perihelion occurring in northern hemisphere summer, low obliquity
e. high eccentricity, perihelion occurring in northern hemisphere summer, low obliquity
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49. The polar front was situated ___________ during last glacial maximum.
a. at the Iberian Peninsula (Portugal and Spain)
b. at the equator
c. at latitude of Mexico
d. at the latitude of Iceland
e. none of the above are correct
50. The temperature changes during the Little Ice Age were about ________ lower than present.
a. 5-10 °C
b. 0°C
c. 5-7 °C
d. 10-15 °C
e. 1-2 °C
Bonus Questions:
51. During the Whidbey Island field trip we visited the Coupeville erratic at __________.
a. Captian Whidbeyís Lodge
b. Coupeville Motor Inn
c. the Big Rock Apartments
d. the Erotic Erratic Bar and Grill
e. the South Whidbey Hospital parking lot
52. During the East Cascades field trip we got stuck __________.
a. in a ditch along Mountain Home Road above Icicle Creek
b. in wet lake sediments in Moses Coulee
c. in the rest stop at Steven Pass
d. on a forestry road above Lake Chelan
e. on the Leavenworth Moraine behind the school parking lot
53. On the Whidbey Island field trip we were looking for _________ in the Partridge gravels at Fort Ebey State Park.
a. pumice clasts
b. mammoth bones
c. foraminifera
d. agates transported by the Cordilleran Ice Sheet
e. buried paleosols
54. On the East Cascades trips our first field stop was ___________.
a. at Late Glacial moraines at Stevens Pass
b. the Wedgewood erratic as we were leaving the U District
c. looking at lake sediments along the Tye River near Skykomish
d. looking at a large gravel pit near Monroe
e. at the Leavenworth Moraines behind the high school in Leavenworth.
55. What factors control d18O ratios in the ice sheets?
a. the source region of the air mass bringing snow to the ice sheet
b. global ocean d18O ratios
c. elevation of the ice sheet where the snow accumulates
d. all of the above are correct
e. none of the above are correct