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Dirt I. The Abiotic Side of Soil. Soils. Soils divided into horizons: Topsoil A horizon - Dark loam, with more organic material than lower layers E horizon - Light loam B Horizon - Subsoil More clay, lighter in color C Horizon - Parent material. Soil profile. How do we get soil?.
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Dirt I The Abiotic Side of Soil
Soils • Soils divided into horizons: • Topsoil • A horizon - Dark loam, with more organic material than lower layers • E horizon - Light loam • B Horizon - Subsoil • More clay, lighter in color • C Horizon - Parent material Soil profile
How do we get soil? • Soil is formed through the interaction of climate, parent material, topography, vegetation, living organisms and time.
Parent material - Rock that has not been broken down into smaller particles
Rock Types • Igneous – Volcanic • Sedimentary - Deposited by glaciers, water or wind • Metamorphic - Changes in igneous or sedimentary rocks from pressure or heat
Igneous - solidified from molten material
Focus on Metamorphic Metamorphic - recrystallized by heat and/or pressure.
Gumbo… not the tasty stew. gumbo: any of various fine-grained silty soils that become waxy and very sticky mud when saturated with water.
Soils: How good is it? Why? • Climatevaries throughout the globe, as does its role in weathering of rocks • Deserts - Little weathering by rain, and soils poorly developed • In areas of moderate rainfall - Well-developed soils • Areas of high rainfall - Excessive water flow through soil leaches out important minerals.