4.2 & 4.3 Soil Formation and Erosion Flashcards
Weathering
the physical, chemical, and biological processes that convert large rock particles into smaller particles
Parent Material
Original rocks broken down to form the basis of soil
What factors contribute to soil formation?
Type of parent material, climate, topography, biological factors, and time
Humus
dark, spongy, crumbly mass of material made of complex organic compounds
Leeching
Soil particles suspended or dissolved in liquid are transported to another location
Erosion
the removal of material from one place and its transport to another by the action of wind or water
Deposition
the arrival of eroded soil at a new location
Soil Horizon
a distinct layer of soil
Sand
does not adhere to one another, 0.05-2mm (very porous)
Silt
powdery when dry, smooth when wet, 0.002-0.05 mm
Clay
readily adhere to each other, sticky when moist, <0.0002 mm (impermeable)
O Horizon
Organic material; living things carry on life activities. Contains carbon with millions of dead plant and animal organisms that are slowly decomposing. Takes 100-600 yrs to form
A Horizon
Topsoil containing humus, organic matter, roots, worms, insects, and other living organisms, small rock and mineral fragments, dark in color
B Horizon
The subsoil, contains some roots and other living organisms, materials leached by water from the A horizon, clay, rock fragments, minerals. Lighter in color than topsoil
C Horizon
Weathered Plant rock, materials leeched by water from B horizon, partly weathered rock fragments. Organish, yellow color
