Geology of Illinois

Garden of the Gods – Shawnee Hills

Apple River, Near Galena

Mississippi Palisades, Savannah, IL

Rockford, Illinois

Starved Rock State Park

Major cycles of variation in temperature

Causes of 100,000 year cycle in temperature variation

EarthduringWisconsinianglaciation

Wisconsinian Glaciation

Wisconsinian vs. Today

Glacial Landforms – North America

Glacial Moraines

Glacial Deposits

• Glacial till - unsorted, unstratified mixture of clay, silt, sand and cobbles deposited directly by glaciers - glaciers pick up tremendous amounts of sediment and rock

• Glacial drift - the general term for sediment and rock left by glaciers is drift - deposits of clay, silt, sand, gravel and boulders left by glaciers or their meltwater streams

Exposed glacial till

Glacial Drift at Fox River Stone Company – St. Charles, IL – 100 feet of drift over

bedrock

Illinois River Valley

Glacial Moraines

Moraines in Illinois – Wisconsinian Glacier

Moraine View State Park

Moraine on Illinois Hwy 4

Recent Geology - Illinois

Endangered Wetland Regions and Endangered Species

Prairie pothole ponds and marshes

Prairie pothole ponds and marshes

Drainage Ditches

Installing drainage tiles

Glacial erratic in Alberta

Glacial Erratic – New York

Exposed Loess Deposit

Glacial Landscape – Cross-section

Glacial Landscape – McHenry County, IL

Illinois Climate

Mean Monthly Temperatures – Urbana, Illinois – 1961-2000

Pollen Data – from Nova Scotia

Tree Distributions – Post-Glacial

Cyclical climate and ecological change at Billy’s Lake, MN

• 10,000 to 8020 BP - jack pine, red pine forest with some oaks

• 8020 to 3400 BP - grassy prairies with sage (5000 to 4000 BP) and with oak after that

• 3400 to 1000 BP - deciduous forest - oak-grass to oak-birch to birch-hornbeam

• 1000 BP to present - pine forest - birch-white pine