Soil
Videos
Soil, also commonly referred to as earth, is a mixture of organic matter, minerals, gases, water, and organisms that together support the life of plants and soil organisms. Some scientific definitions
Surface-water-gley developed in glacial till in Northern Ireland
Soil measuring and surveying device
A, B, and C represent the soil profile, a notation firstly coined by Vasily Dokuchaev (1846–1903), the father of pedology. Here, A is the topsoil; B is a regolith; C is a saprolite (a less-weathered regolith); the bottom-most layer represents the bedrock.
Desertification
Clay
Videos
Clay is a type of fine-grained natural soil material containing clay minerals. Most pure clay minerals are white or light-coloured, but natural clays show a variety of colours from impurities, such as
Soil
…the lithopedon (in contact with the subsoil). The soil texture is determined by the relative proportions of the individual particles of sand, silt, and clay that make up the soil. The interaction of the individual mineral particles with organic matter, water, gases via biotic and abiotic processes causes…
Boulder clay cliff south of Withernsea, England
A 23,500 times magnified electron micrograph of smectite clay
Italian and African-American clay miners in mine shaft, 1910
Clay layers in a construction site in Auckland, New Zealand. Dry clay is normally much more stable than sand in excavations.