Weathering and Soil Types of Weathering Chemical Weathering

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 typespedalfer, 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