Our Earth (1.5 hours)

In the classroom, students will microscopically examine samples soil to see what they look like and how they differ.  Using a set of sieves, students will be given a quantity of dried soil that they will sift through the sieves, dividing it up into its various sized components for a textural analysis.  Diagrams and discussion will introduce the concepts of erogony (mountain building through tectonic activity ie: uplift), erosion and deposition (water, wind and frost as agents of erosion, with running water as the agent of deposition). With a hike onto the preserve, students will see some examples of deposition and erosion (stream erosion, bank undercutting, sandbar deposition, glacial depostion eg. esker), and will examine  several soil profiles by taking samples with a soil probe ( O-Horizon, organic layer; A-Horizon - surface mineral layer, where organic matter mixes with mineral layer; E-Horizon - eluvial layer where organic and inorganic material have been leached from the overlying layer by organic acids, B-Horizon (horizon where leached materials accumulate, and the C-Horizon, parent material layer).  The instructor will explain how soil is formed and what the various layers are composed of.  Students will learn how soil is formed, where it comes from, how it is layered, and the organisms that rely on it.