13 terms

Stages of Weathering

hard, unweathered rock of the planet
The first stage of weathering bedrock is to produce a layer of rock chips, pebbles, and fragments
a dark material composed of decaying organic matter
Parent Rock
The original rock that was weathered
Transported Soil
Sometimes soil is not related to the rock it sits on or to a nearby rock
Residual Soil
stays put on top of its parent rock
This soil often develops distinct layers called horizons
Horizon A- Topsoil
Water leaches minerals form here
Horizon B- Subsoil
Contains minerals leached from the topsoil of Horizon A. Contains clay and perhaps some hummus. May contain the minerals remaining after water has evaporated.
Horizon C- Partly Weathered Bedrock
This is in the first stages of chemical and mechanical weathering. Continued weathering will turn into Horizon B or even Horizon A material. Transported soil is an undifferentiated mix of material and has no horizon.
In tropical climates, the heavy rains cause rapid chemical weathering.
Rains about 25 inches per year. Contains clay, quartz, and iron. Found in states east of the Mississippi River and in the Gulf Cast states.
Rains about 25 inches per year. Contain calcium carbonate which combines with excess hydrogen to make soil less acidic. Found in states west of the Mississippi Rive. A very fertile soil
lay of the land, is a factor in soil development