continental glaciers (ice sheets) and illinois glaciation

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