The Udell Moraines

Moraines are ridges or mounds of rock, soil, and debris deposited by a moving glacier. They are composed of unsorted glacial till--a mixture of boulders, pebbles, and finer materials--that was picked up and carried by the ice and then left behind as the glacier melts or retreats. Common types of moraines include lateral (along the sides), medial (between two merging glaciers), terminal (at the glacier's furthest advance), and ground (blanketing the land where a glacier melted).

Over the last two million years, glaciers repeatedly advanced and retreated across the Michigan area. The final major glaciation, when Michigan was largely covered by glaciers, was during the Wisconsinan glaciation, which was part of the Pleistocene Epoch. As the Laurentide Ice Sheet receded, Michigan began to emerge from the ice over the last 14,000 to 10,000 years. This final glaciation was when the Udell moraines were formed.

You can tell the different types of moraines by their characteristics. Terminal moraines appear as a large mound or ridge that spreads across a valley floor. Lateral moraines appear as long, high mounds of debris that are often steeper close to the glacier. Medial moraines appear as a ridge of material that represents combined lateral moraines of two merging glaciers. Ground moraines appear as a layer of debris forming a flat plain.

This is an earthcache with a lesson in geology. To log this cache, send answers to the following questions and post a picture:

1)  Driving east toward the posted coordinates, you will drive through the Udell Hills. How many hills do you drive over?
2)  In your own words describe the type of moraines these are based on the reading and your observations of the area.
3)  At the posted coordinates, describe what sediments make up the glacial till (type of ground).