Glacial Features Around St. Walburg

Eskers Ice tunnels formed within the glacier. As the ice melted in and around these tunnels, beds of sand and gravel (which accumulated as the ice pack scraped forward) were deposited in long, snake-like ridges.

            A cross section of an Esker

Moraine At the front of the retreating glacier, mounds of unsorted soil particles including sand, gravel and small and large rocks were deposited. Between St. Walburg and the Village of Spruce Lake, a series of terminal moraines were left behind signifying rapid retreat and then slowing down, rapid retreat and then slowing down... 

Terminal moraine south of St. Walburg

Glacial Spillways As the glaciers melted, the flowing meltwater cut channels in the land creating outflow valleys. The river water carried enormous amounts of silt, sand and fine gravel which as the water slowed, was deposited in layers along the banks. 

The Englishman River   Deposited silt

ErraticsThe glacier scraped, scooped up and carried rocks of many sizes great distances. As the ice melted, these rocks were deposited. Very often their makeup is not at all similar to the bedrock underlying them.

TillSoil rubble left by a retreating glacier.

Unsorted material

Kettle Holes A chunk of ice sometimes would break away from the main pack and create a depression in the ground. As meltwater flowed by these chunks of ice, silt and sand were deposited around and over the top of the chunk of ice. When the ice melted the soil settled causing raised edges which would fill with water, hence the reference to kettle. These features are also known as fluvial pits. I know them better as sloughs.

A typical kettle hole or fluvial pit

Soil ProfileAs glacial particles were deposited the heaviest particles settled first. Over the course of thousands of years, decaying vegetation added organic material to the surface of the profile giving it a much darker appearance. The soil located deeper in the profile has little nutritional value to plants. Often rocks are caught in the layers of the profile. This is known as boulder clay.

If you look closely at the picture you can see boulders which gives it the name, boulder clay.