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Continental Glaciers(Ice Sheets)
and
Illinois Glaciation
Phanerozoic – EON
Cenozoic – ERA
Quaternary – PERIOD
Pleistocene - EPOCH
(1.8 mya - 10,000 years ago)
2. Ice sheets (Continental glacier)
• Large scale – cover 10% of Earth’s land
Greenland – 1.7 million km2
Antartica – 13.9 million km2
Glacier Types
Continental Glaciers
Glaciation in Illinois
1. Wisconsinan 75,000 – 10,000 ya
2. Illinoian 300,000 – 125,000 ya
3. Kansan 700,000 – 500,000 ya
4. Nebraskan 1,800,000 – 900,000 ya
Glaciation in Illinois
1. Wisconsinan 75,000 – 10,000 ya
2. Illinoian 300,000 – 125,000 ya
3. Pre-Illinoian
End moraines
and
till plains
Glacial Deposits
Drift – Sediment deposited on land or in water as a result of glaciation.
Till – Unsorted debris transported by glaciers and deposited on land.
Diamicton – Does not infer digenesis
Moraine – a sediment pile composed of till deposited by a glacier
Glacial Deposits
Till – Mixture of unsorted mud, sand, pebbles, and larger rocks deposited by glaciers
Ice Sheet Landforms
Outwash – sand and gravels deposited by glacial meltwater
Pro-Glacial Lake Sediments
Ice Sheet Landforms – Kettle Lakes
Ice Sheet Landforms - Eskers
Ice Sheet Landforms - Drumlins
Ice Sheet Landforms
Drumlins
Glaciation relocated rivers
Pre-Illinoian Drainage
Illinoian Glaciation & Drainage
Wisconsinan Glaciation & Drainage
Lobes
And
Moranic systems
Chief Waupansee
Was this change unique in time?
Why did the climate change?
Points to Ponder
1. changing continental positions
2. uplift of continental blocks
3. reduction of CO2 in the atmosphere
4. changes in the Earth's orbit
Why did the climate change?
Plate Tectonics is one of the keys to paleozoic glaciation 250 million years ago
Changes in Earth’s Orbit
• The Milankovitch Theory
The Milankovitch Theory
Eccentricity of the orbit
Changes in Earth’s tilt
The Milankovitch Theory
Earth-Sun Relations
Precession of the Equinoxes
The Milankovitch Theory
Cycles of Global Warming
Snowball Earth