1

• Mesozoic climates were generally warm because there were no continents at the poles.
• Cretaceous climate is warm & wet because the continents are significantly dispersed & sea level is high due to fast seafloor spreading rates along the Mid-Ocean Ridge.
• Movement of the continents by plate tectonics & decreasing sea level resulting from decreased rates of seafloor spreading along the Mid-Ocean Ridge had no effect on Cenozoic climate.
• The temperature of bottom waters in the ocean changed from about 15 degrees C during the Cretaceous & early Tertiary to -1 degrees C at present.
• Antarctica became permanently ice-covered during the Cretaceous Period.
• Antarctica became permanently ice-covered during the Mesozoic Era.
• Significant glaciation of Antarctica began during the Late Eocene and Early Oligocene (~40 to 35 my ago).
• Greenland became permanently ice covered 15 my ago.
• The climate at the beginning of the Mesozoic was _________.

  A. warm B. cool C. dry D. both A & C E. both B & C

• Greenland (in the Northern Hemisphere) became permanently ice-covered during the _____________.

  A. Triassic (~225 my ago) B. Jurassic (~175 my ago) C. Cretaceous (~100 my ago) D. Eocene (~45 my ago) E. Late Pliocene (~2.4 my ago)

• Antarctica (in the Southern Hemisphere) became permanently ice-covered during the ___________.

  A. Triassic (~225 my ago) B. Jurassic (~175 my ago) C. Cretaceous (~100 my ago) D. Miocene (~15 my ago) E. Late Pleistocene (~25 ky ago)

2

• There were only 4 advances & retreats of the Northern Hemisphere ice sheets during the Pleistocene.
• Terrestrial glacial deposits in North America & Eurasia record more than 15 advances & retreats of continental glaciers during the last 1 my.
• Terrestrial glacial deposits record many more advances and retreats of ice than do deep marine sediments.
• No widely accepted hypothesis as to the cause of the glacial to interglacial cycles during the Quaternary Period has been presented by climatologists.
• The glacial to interglacial fluctuations apparent during the last 2.4 my are apparently caused by variations in the Earth's orbit that vary the amount of sunlight received at critical spots on the Earth's surface.
• The glacial to interglacial cycles of the Quaternary Period are due to small changes in the amount of sunlight the Earth receives that result from small changes in the characteristics of the Earth's orbit.
• The glacial to interglacial cycles of the Quaternary Period are caused by small changes in the rate of seafloor spreading along the Mid-Ocean Ridge.
• The CO2 content of air trapped in bubbles in Greenland and Antarctic ice cores is relatively high (~290 ppm) during glacial advances & relatively low (~200 ppm) during interglacials.
• The CO2 content of the atmosphere changed from ~79% during the last 2 glacial advances (~140 & 18 ky ago) to ~20% during the last 2 interglacials (~125 ky ago & the present prior to 1850).
• How many Quaternary glacial advances & retreats are recorded by terrestrial glacial deposits?

  A. 4 B. 5.5 C. 10 D. 25 E. more than 30

• Which of the following is a true statement about the Earth's orbital characteristics?
  • A. The eccentricity of the Earth's orbit varies with a frequency of 26,000 years.
  • B. Precession of the rotational axis occurs with a frequency of 41,000 years.
  • A. The eccentricity of the Earth's orbit varies with a frequency of 41,000 years.
  • B. Precession of the rotational axis occurs with a frequency of 26,000 years.
  • C. The tilt of the rotational axis changes from 32-34° with a frequency of 100,000 years. D. all of these. E. none of these.
• Quaternary glacial advances occur when:
  • A. the axial tilt is large (24°), precession has the northern hemisphere summer occurring when the Earth is closest to the Sun, & eccentricity is minimum.
  • B. the axial tilt is small (22°), precession has the northern hemisphere summer occurring when the Earth is farthest from the Sun, & eccentricity is maximum.
  • C. the axial tilt is intermediate (23°), precession has the northern hemisphere summer occurring when the Earth is farthest from the Sun, & eccentricity is minimum.
  • D. the axial tilt is large (24°), precession has the northern hemisphere winter occurring when the Earth is farthest from the Sun, & eccentricity is intermediate.
  • E. none of these.
• The glacial to interglacial cycles of the Quaternary Period are due to ________________.
  • A. large changes in the rate of seafloor spreading along the Mid-Ocean Ridge
  • B. large changes in the amount of sunlight the Earth receives that result from small changes in the characteristics of the Earth's orbit
  • C. small changes in the rate of seafloor spreading along the Mid-Ocean Ridge
  • D. small changes in the amount of sunlight the Earth receives that result from small changes in the characteristics of the Earth's orbit
  • E. no one knows why there have been glacial to interglacial cycles during the Quaternary Period
• The CO2 content of the atmosphere changed from _______ during the last 2 glacial advances (~140 & 18 ky ago) to _________ during the last 2 interglacials (~125 ky ago & the present prior to 1850).

  A. ~700 ppm, ~350 ppm B. ~290 ppm, ~200 ppm C. ~200 ppm, ~290 ppm D. ~79%, ~20 % E. ~20%, ~79%

• The concentration of CO2 in the Earth's atmosphere during the last glacial episode was:

  A. 100 ppm. B. 200 ppm. C. 350 ppm. D. 600 ppm. E. 3000 ppm.

• The CO2 content of the atmosphere changed from _______ during the last glacial advance to _________ during the present interglacial prior to 1850.

  A. 700 ppm, 350 ppm B. 290 ppm, 200 ppm C. 200 ppm, 290 ppm D. 79%, 20 % E. 350 ppm, 200 ppm