Soil and soil mechanics Mohammed Jameel 201403603 Dr

Soil and soil mechanics Mohammed Jameel 201403603 Dr. Saidur Rahman Chowdhury Geology Talal AL-Qahtani 201301714

Outline: DIFNATION OF SOIL. . Soil Formation Soil profile Soil Horizons Types of soil

DIFNATION OF SOIL. . Soil is a mixture of organic matter, minerals, gases, liquids, and organisms all the fragmented mineral material at or near the surface of the earth, the moon, or other planetary body, plus the air, water, organic matter, and other substances which may be included therein”.

How does soil form? Residual soils form by weathering of rock in place Transported soils develop by weathering of sediment Every soil originally formed from parent material: a deposit at the Earth’s surface. The material could have been bedrock that weathered in place or smaller materials carried by flooding rivers, moving glaciers, or blowing winds. Over time, sun, water, wind, ice, and living creatures help transform, or change, the parent material into soil.

WHAT IS THE Factors Influencing Soil Formation? Climate • (most important) Time • Earthworms • Burrowing animals • Plant roots • Bacteria and Fungi (decomposers) • Position on slope • Rainfall • Soil p. H

Climate and Soil Climate is the most important factor in soil formation because of its strong influence on chemical weathering. Parent material, relief and slope, organisms, and time are other factors. Climate affects soil type, thickness, and fertility

Time and soil The rate of soil formation varies extensively from site-to-site because it is dependent on the other soil- forming factors. Nonetheless, an overall average of about 2. 5 cm/100 years is often quoted. Soil formation operates rapidly in the context of geologic time, but is a slow process from the human perspective.

Soil Horizons O) Organic matter: Litter layer of plant residues in relatively undecomposed form. A) Surface soil: Layer of mineral soil with most organic matter accumulation and soil life b)Subsoil: This layer accumulates iron, clay, aluminium and organic compounds C) Parent rock: Layer of large unbroken rocks. R) bedrock: R horizons denote the layer of partially weathered bedrock at the base of the soil profile.

Gravel Sand Silt Clay

Gravel soil Gravel is a loose aggregation of rock fragments. Gravel is classified by particle size range and includes size classes from granule- to boulder-sized fragments The size of gravel soil (2 mm to 75 mm) Gravel

Sand soil Sand is a naturally occurring granular material composed of finely divided rock and mineral particles. The size of sand soil (0. 05 mm – 2 mm) Sand

Silt soil Silt is granular material of a size between sand clay, whose mineral origin is quartz The size of silt soil (0. 002 mm – 0. 05 mm) silt

Clay soil Clay is a finely-grained natural rock or soil material that combines one or more clay minerals with possible traces of quartz, metal oxides and organic matter. clay

Video of soil prosperities https: //www. youtube. com/watch? v=ko-GJDbn. XE 8

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