Glaciers

Glaciers. Ancient ice sheets shaped northeast Kansas' landscape. , While thoughts of Kansas do not typically conjure images of glaciers, these ancient ice sheets shaped northeast Kansas' landscape of rolling hills and rock-strewn valleys as little as 600,000 years ago. Glaciers are some of earth's largest moving objects - rivers of ice formed when snow falls more than it melts. As snow piles up over hundreds or thousands of years, it begins to move under its own weight by either spreading or by sliding down a slope. Glaciers "flow" because the intense pressure makes layers of ice flexible; however, upper layers remain brittle., During the ice age, two glaciers advanced into Kansas. , Called the Independence glaciations, the first only covered the northeastern tip of Kansas, while the second reached south to the Kansas River and west to the Big Blue River. Ice was as thick as 500 feet in some areas. As the glaciers crossed the landscape, they left behind sediment from their path called tills, including remnants of clay, silt, sand, boulders, plants, and animals. In Kansas, the first glacier left the remains of a dead spruce forest as a dark gray till, suggesting that the trees had died as the ice approached. The latter deposited a brown till and erratics, many of which are still visible today., Loess , Loess is a windblown silt created by the movement of the glaciers. As ice moved over the land, it ground rock into a fine-grained sediment. Water from melting glaciers then deposited this silt into river valleys where intense winds blew it further abroad. Around the Missouri River floodplain, loess covers the landscape, forming hills of up to 350 feet. Because loess is porous, it is especially fertile, allowing roots to easily penetrate the soil and absorb nutrients. However, it can be prone to erosion., Erratics , During glaciation, the movement of ice broke large boulders off from outcrops in South Dakota, lowa, and Minnesota, carrying them all the way to Kansas. Often these boulders, called erratics, are hard and erosion-resistant rock, such as the pinkish Sioux quartzite boulders originally from the mountains in South Dakota., Glaciers and Agriculture , The glaciated regions' natural vegetation is mostly comprised of forests and grasslands. Tall-to-medium prairie grasses cover much of the west and central part of the region, while forests are found in the eastern part. A transition area with both prairie and forest together separates the two. The loess soils that supported this vegetation also made the Glacial Hills ideal for agriculture. As a result, farmers have cultivated much of the land, using the rich soil to harvest crops since settlement. In most areas, corn, soybeans, hay, and cattle are the most important agricultural products, though sorghum, dairy milk, and wheat also play a role in the region.