Gravel pit

This is the first station in the field study guide, although your group may not have started here. In fact you probably finished the trip here. This enitre station is located on top of a deposit of sediments left behind by a glacier. The sediments are mixed in size, varied in composition and origin, and sub-rounded in shape. Over at the outcrop, you can view an immature soil profile. The upper layer with roots, insect burrows, etc is a slightly darker color, this is due to the humus (decaying organic material) in the A Horizon. Below that, is a layer of broken up bedrock with no organic materials or minerals to speak of. This is called the C Horizon. There is no B horizon, that is because this sediment was deposited by the retreat of the glaciers at the end of the last ice age, approximately 15 to 12 thousand years ago. Top soil forms at an average rate of 1 cm per 400 years. There has not been enough time for a B-horizon to form. That is why this is called an immature soil profile.