This earthcache is located north of Wadena, Minnesota on County Road 75 just north of the Leaf River. The drumlin to be observed is a few miles to the north of this spot on the east side of the road.
A Drumlin (Irish for “little ridge”) is an elongated hill in the shape of an inverted spoon formed by glacial ice moving on top of the underlying glacial till (rocks, sand, and gravel). Drumlins form near the edge of glacial systems where there is a fast flow of glacial meltwater deep within the ice sheets. They are typically .62 to 1.29 miles long, less than 160 feet high, and 980 to 1970 feet wide. Drumlins may comprise layers of clay, silt, sand, gravel, and boulders in various proportions- perhaps indicating that material was repeatedly added to the underlying core of glacial till. A thin layer of topsoil often accumulates at the top layer.
Tens of thousands of years ago the Wadena Ice Lobe deposited drumlins and other glacial drift in Wadena County and adjacent parts of West Central Minnesota. Referred to as the Wadena Drumlin Field, it has a fanlike form that runs from east to west in a 70 mile arc. The fan pattern suggests that the glacial ice movement was from the northeast. It is estimated that these drumlins are about 30,000 to 60,000 years old.
To receive credit for this earthcache, send your answers to the following questions as a message to my Geocaching Profile page:
- Estimate the height of the drumlin visible to the north and on the east side of the road.
- Describe the landscape around you. Why do you think this type of landscape is here?
- Why do geologists think drumlins run from east to west in the Wadena Drumlin Field?