Soil morphology is the study of the formation and description of soil types within various soil horizons. C.F. Marbut championed reliance on soil morphology instead of on theories of pedogenesis for soil classification because theories of soil genesis are both ephemeral and dynamic. Observable attributes typically analyzed in the field include the composition, form, soil structure and organization of the soil. Color of the base soil and features such as mottling, distribution of roots and pores, consistency of the soil and evidence of mineral presence also contribute to the classification. The observations are typically performed on a soil profile in order to analyze the various soil horizons. A profile is a vertical cut, two-dimensional, in the soil and bounds one side of a pedon. A pedon is the smallest unit, containing all soil horizons. Pedons are typically 1 square meter on top and capture the lateral range of variability of the soil down to the bedrock. Soil horizons Soil horizons are different layers of a soil profile that are characterized by different properties obtained from various soil forming processes. O Horizon - layer that is dominated by organic material, usually from plant or animal litter. This horizon is subject to rapid change, and thus not usually used in the description of a soil. A Horizon - Layer formed just below the O horizon, usually referred to as the topsoil. This layer is a mineral horizon that has been darkened by organic matter. E Horizon - Mineral horizon that is characterized by the loss of oxides, iron, and clay through the process of leaching, also known as eluviation. Usually has a high concentration of sand and silt particles as the clay is leached out. B Horizon - Mineral horizon that is defined by the materials that have accumulated from the above horizons. The minerals and oxides that were lost to eluviation in the above E horizon illuviate into this layer. C Horizon - Layer that is most representative of the soil’s parent material. Made up of semi-weathered material that is between soil and rock. This is the layer that holds the most biological activity. R Layer - Unconsolidated bedrock Soil formation Form Soils are formed from their respective parent material, which may or may not match the composition of the bedrock that they lie on top of. Through biological and chemical processes as well as natural processes such as wind and