Soil By: Alejandro Meza Moreno Lina Lovera Valeria Morales

Types of soil There are many Types of soil that form the crust for exampel the humus, the top soil, eluviation layer, the sub soil, the regolish and finally the bed rock. Up next i will show you the layers and then explain themto you.

The order of the layers

Top soil layer Topsoil is the upper surface of the Earth's crust, and usually is no deeper than approximately eight inches (20 centimeters). The Earth's topsoil mixes rich humus with minerals and composted material, resulting in a nutritious substrate for plants and trees.

Humus layer The humus layer is the first layer of the soil its also the layer of organic soil. The organic matter largely is built up by the death and decay of organisms that live in soil. Some such organisms include bacteria, beetles, earthworms, and moles.

Eluviation layer This eluviation (leaching) layer is light in color; this layer is beneath the A Horizon and above the B Horizon. It is made up mostly of sand and silt, having lost most of its minerals and clay as water drips through the soil (in the process of eluviation).

Sub soil It contains clay and mineral deposits (like iron, aluminum oxides, and calcium carbonate) that it receives from layers above it when mineralized water drips from the soil above.

Regolith layer It consists of slightly broken-up bedrock. Plant roots do not penetrate into this layer; very little organic material is found in this layer

Bed rock The unweathered rock (bedrock) layer that is beneath all the other layers.