Cenozoic Era

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Cenozoic Era
http//www.ucmp.berkeley.edu/cenozoic/cenozoic.htm
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Events of the Cenozoic

• The final breakup of Pangea.

• India collides with Asia to form the Himalayas.

• Australia and S. America tear away from
  Antarctica.

• Africa collides with Europe to form the Alps.

• The Farallon plate subducts under the N. American
  plate. This causes volcanic events that lead to
  the formation (uplift) of the western basin and
  range system and the formation of the Cascade
  Mtn. Range.

• The northwest movement of the Pacific plate
  causes the transform faulting of S. California
  and the formation of San Andreas fault system.

• The Great Ice Age

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Glaciation Theories

• Changes in solar radiation

• Astronomical or orbital effects involving changes
  in the earth-sun geometry. Milankovitch Cycles
  p.482

• Terrestrial changes Atmospheric transparency or
  changes in the Earths surface reflectivity.

• Variation in heat exchange rates due to changes
  in ocean currents. Pangea breakup.

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GLACIAL GEOLOGY TERMS
Ablation- the processes by which snow ,ice, or
water are lost from a glacier. Accumulation- the
processes by which snow and ice build up
(accumulate) to form a glacier Glacial Till or
Till- Unsorted, unstratified mixture of fine and
coarse rock debris deposited by a
glacier. Moraine- Rock debris deposited by
glacier. Lateral Moraine- Piles of loose
unsorted rocks along the side margins of a
glacier. Terminal (End) Moraine- Piles of loose
unsorted rock at the leading margins of a
glacier. Loess- Finely ground material that is
deposited by glacial melt waters and
then transported by wind to form a blanket of
fine soil forming material. A loess soil
consists of a mixture of sand, silt and
clay. Glacial Landforms- kames, kettles, flutes,
drumlins, erratics and eskers.
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THE GREAT ICE AGE

• During the Pleistocene epoch ice sheets up to
  8000 feet thick advanced and retreated several
  times into N. America
• 4 major glaciations separated by 4 interglacial
  periods over the last 1.6 million years.
• Glacial Periods Nebraskan, Kansan, Illinoian,
  and Wisconsinan
• Interglacial Periods Aftonian, Yarmouth,
  Sangamon, and
• the present.
• No record of the Nebraskan or Kansan glaciers in
  Illinois
• Yarmouth formed the Mehomet River Basin,
  Sangamon formed the Illinois River Basin

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Illinois Geologic Column
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Illinois Bedrock Geology
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Glacial History of Illinois
http//jove.geol.niu.edu/faculty/fischer/429_info/
429trips/NIF/Glaciers.htm_Illinois_Glacial_Histor
y
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Glacial Deposits Map
Search Site Map About ISGS Employment
Contact Us HomeIllinois Department of Natural
Resources State of Illinois
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Wisconsin Glacial Episode
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Loess Thickness Map
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Paleontology of Illinois
http//www.paleoportal.org/