Transcript River PPT2

Tom
Karen
Paul
Jessie B.
Ethan
Leah
Katie
Jess
Brianna
Emily
Bear
Abby
Melissa
Jesse
Jessie C.
Soil~ The top layer of the earth's surface, consisting of rock and mineral particles
mixed with organic matter.
• O Horizon~ Organic Matter( No Mineral)
•A Horizon~ Mixture of organic matter and minerals
•B Horizon~ Slightly weathered mineral
•C Horizon~ Unweathered mineral
•Bedrock
Topsoil is a crucial layer
because it holds moisture and
very important nutrients for plant
life.
It takes about 500
years to develop 1
new inch of topsoil.
Topsoil has the highest
concentration of organic matter
and microorganisms.
 A good way to tell what kind of
history a piece of land has is through it’s
soil. If the soil in a given piece of land
contains large round rocks, it is safe to
assume that at one point in time a river
was running through that land.
 Another way to tell the history of a
piece of land is if the line of separation
between the A Horizon (organic matter and
minerals) and the O Horizon is a straight
line. This indicates that the land was once
plowed.