Content adapted with permission from the Indiana Geological Survey, a partner in the Natural Heritage of Indiana project. Credit for this article goes to Ned Bleuer and Deborah DeChurch. More information can be found here.
Left much as when the last glacier melted 16,000 years ago, the landscape today reflects a series of climate-related surges of the massive Laurentide ice sheet that still covered all Canada and parts of the Midwest. About 17,000 years ago, a tongue of the ice sheet surged southwestward to Indianapolis, then melted in place over many centuries. The icy surface was covered with deep crevasses and frigid ice-walled lakes in what is now Russiaville. Eventually the ice advanced again straight westward, carving the remarkable Young America flute field (mostly north of State Road 18), and then again southwestward to form the Windfall crevasse fan. Finally, the glacier made one last massive advance to the Union City Moraine.
Beneath the scoured glacial debris, called "drift," is the land surface as it was before the presence of the glacier, about a million years ago. The thick rich soils that grow Indiana's corn and soybeans owe their existence to this glacial debris. This soil is one of the most beneficial legacies of the ice age; Indiana's agricultural wealth can be attributed, in part, to sediments carried by the glaciers from as far away as Canada. Buried soils represent warm periods between glacial advances and are key markers for geologists sorting out the periods of time that the ice surged and retreated.
The understanding of glaciers and the geology of the region is tied to future planning for land use, the extraction of minerals, and the protection of the ground water we need for drinking and irrigation of farmland. These issues are directly related to the nature of glacial deposits, since aquifers—the water-bearing formations under the surface—are also part of the legacy of the glaciers. More»
Get the Book: The Natural Heritage of Indiana Marion Jackson described his vision for the book The Natural Heritage of Indiana as “a celebration of Indiana’s natural heritage – its natural and human history, its landscape and its life – what it once was, what it is now, and what it promises to be.” He emphasizes the importance of understanding the past to prepare “us better to mold Indiana’s future.” He issued this challenge: “if you feel moved to help protect what remains of Indiana’s natural heritage, our objective will have been fulfilled.” This lavishly illustrated book contains essays by Indiana's leading scholar-teachers and concludes with "a call to arms for those who would presernve Indiana's environment. Purchase the book»
Get the DVD or VHS: Naturally Indiana Host Michael Atwood will lead viewers on a breathtaking tour of Indiana's state parks, nature preserves, and other natural wonders that make the Hoosier landscape so unique. Set against a backdrop of changing seasons, Naturally Indiana is a spectacular journey through the state's four major eco-regions: Tallgrass Prairie (Central), Great Lakes (Northwest), Tillplain (North Central) and Low Plateau (Southern Indiana). Producer J. Robert Cook and his production team spent ten months on-location in some of Indiana's most treasured state parks, nature preserves and fish and wildlife areas. The result is a picturesque video postcard of Indiana that captures the subtle power of Clifty Falls in Southern Indiana, the regal glory of the Northern Dunes, the quiet grace of Kankakee Sands, the shaded depths of the Southern Highlands, and many more Indiana gems. Purchase DVD or VHS»