Weathering and Soil
Types of Weathering Chemical Weathering: a rock being changed into 1 or more new compounds Oxidation- turns the rock into a rusty color Acid Rain- Acid in the rain breaks down the rock Biological Activity – acids from plants weather rocks Dissolution- when the rock dissolves in a solvent Carbonic Acid- deterioration of rock causing it to change color or texture Spheroidal Weathering- water breaks down minerals into a spherical shape. Mechanical Weathering: the breaking down of a rock, the rock’s mineral composition does not change. Unloading and Exfoliation- rock breaks off in sheets of layer Abrasion- the wearing down of rock particles by friction due to water, wind or ice. Frost Wedging- The process of water freezing and expanding in the cracks of rocks, making the cracks larger Biological Activity- activities by organisms like animals, plants and humans that cause weathering. (ie burrowing)
Soil - Weathered rocks that form the top layer of Earth’s surface. There are 3 types- pedalfer, pedocal, and laterite. Pedalfer Soil Pedocal
Soil Composition
Soil Profile Horizon A (Topsoil)- Loose and partly decayed organic matter Horizon B (Subsoil)- Clay transported from C horizon Horizon C- Partially weathered plant material Unweathered Plant Material
Soil and Climate
Temperate Climates Pedalfer is formed in temperate climates. Pedalfer is found in the Eastern US, mostly in forests. Pedalfer is rich in iron, has lots of aluminum rich clays and is brown to red-brown in color.
Desert Climates Pedocal is found in dry climates. It can be found in the Western US. Pedocal is rich in calcite, and calcium carbonate. Light grey-brown
Humid Tropical Climates Laterite soil is formed in humid, hot climates in the tropics. Found in places like Cambodia and Southeast Asia. Laterite has lots of iron and aluminum