Process that breaks down rock and other substances at Earth's surface

heat,cold,water,and ice all contribute

oxygen and carbon dioxide in the atmosphere as well

the removal of rock particles by wind, water, ice and gravity

the principle states that the same processes that operate today operated in the past-- that is weathering and erosion have shaped the Earth's surface millions of years ago

the weathering and erosion that happens today also happened millions of years ago

the type of weathering in which rock is physically broken into smaller peices over long periods of time

examples:freezing and thawing, erosion, animal actions,plant growth and abrasion

the process of the freezing and thawing of water as water seems into cracks in rocks and freezes and ice acts as awedge that forces things apart...the wedges widen and deepen the cracks

breaks down rocks through chemical changes

causes include the action of water which can disolve rock over time, oxygen combined with iron and water creates oxidation (rust) which crumbles rock, carbon dioxide mixed with rain and water goes in soil and weathers marble and limestone, living organisms send roots into weakened rocks and acid rain chemically weather rocks as pollution mixes with air and rains onto the Earth

it produces new minerals in rocks as it breaks it down

The Type of Rock (the minerals that disolve easily that make up the rock determine how fast the rock weathers)

and 

Climate (where it is both wet and hot it weathers fastest)

a material is full of tiny, connected air spaces that allow water to seep through it.  this type of rock weathers chemically at a fast rate

water seeps through, dissolves it and removes material broken down by weathering

soil that is made up of equal parts of clay, sand, and silt. it has a crumbly texture and holds air and water. it is the best for growing most types of plants

soil made from clay, sand and silt. Crumbly, holds air and good for plants

C is contains only WEATHERED ROCK and is LIGHT brown

Below it is Big Rocks called Bedrock

scientists classify the different tyles ofsoil into major groupsbased on:

• climate
• plants
• soil composition

make humus, the material that makes soil fertile

OR

mix the soil and make spaces in it for air and water

living organisms in soil that turn litter and dead organic material into humus by breaking the remains of this stuff into smaller pieces and digest them with chemicals

very small animals like mits and worms decompose and mix material with the soil