Landforms are essentially the lay of the land, or the qualities that determine Earth’s landscapes. Examples of landforms are mountains, plateaus and canyons. They are always changing, shaped by geologic forces deep underground and also by climate. Climate acts to wear away the parent stones, transporting and redepositing different substances as they weather off. As stones degrade into small particles, the particles aggregate to form soils. It can take thousands of years to make a small quantity of soil. Soils exist almost everywhere, supporting Earth’s plant and animal life.
Parent Rocks
Parent stones are formed through the years by volcanic action, metamorphosis because of heat and pressure applied to substances within the Earth, and also by sedimentation, where water action deposits materials which then descend into stone. The different parent rocks give rise to soils with different qualities, such as particle size, pH, and also the sorts of minerals that they have in them. They affect the soil’s colour, structure, drainage and texture. The United States alone has over 50,000 distinct soils.
Weathering and Erosion
Two of the major climatic factors which cause rocks to weather are moisture and temperature. Water seeps into rock crevices, and as it freezes in cold weather and also heats in warm temperatures, it expands and contracts, making pressures that can break stones. Weathered stone is subject to further breakdown from erosion. The climatic factors of rain, hail, snow, and end all behave to wear away stone, breaking it into smaller particles Wind can have a scouring effect, driving sand against parent stone and abrading the exposed surfaces. Weathering and erosion result in the basic soil particles of sand, silt and clay.
Transporting Agents
After particles weather out of their parent stones, the particles can get transported from the area they’re formed in from the action of wind, rain and bodies of water. Rain washes out finer soil particles, carrying it downstream to redeposit in lakebeds or alluvial fans. When glaciers are present, as they spread they carry as deposits of rock and soil materials that can travel long distances over time. Glaciers also scrape parent rock material, helping it to split into bigger particles. Glaciers wear away stones to form U-shaped valleys in mountain systems throughout the world.
Soil Organic Material
Once soil particles have been formed, climate proceeds to behave on soil characteristics by changing the quantity of organic material present in different soil types. Plants contribute organic matter to soils as they perish and decay, using the result being a natural substance called humus. The organic substance is important to retain soil moisture and also to hold on to mineral nutrients required for plant growth in order that they do not leach away. The organic substance decays more quickly in regions with a moist, warm climate. It can have quite a long time for organic material to decompose in cold or waterlogged soils.
