Download Chapter 7 – Weathering and Erosion

Chapter 7 – Weathering and Soil
Section 7-2: The Nature of Soil
Study Guide

Soil
______________ is a mixture of weathered ____________, decayed
_____________ _____________, ________________ fragments,
______________, and ______________.

Soil can take ________________ of years to form.

There are _________ factors that affect soil formation:
1.
2.
3.
4.
5.

Different soils develop in different ________________; tropical soil is different
than _____________ soil.

Soils that develop on ____________ slopes are different than soils that develop on
__________ land.
Composition
of Soil

The rock and mineral fragments found in soils come from__________ that have
been ______________.

Organic matter in soil comes from _______________, ________________, and
________________________.

Decayed organic matter turns into ________________, a source of
________________ for plants.

Soil has many _____________ between particles that holds __________ and
___________________.
Soil Profiles

Different layers of soil are called _______________________.

All the horizons of a soil form a ______________ _________________.

There are __________ main horizons for most soils.
o _______ Horizon: the _______ layer of soil.

It is usually covered by ___________, made up of leaves, twigs,
and organic matter, which helps prevent _____________ and
_______________________ of water from the soil.

Also known as _________ _______________.

It is ___________ in color and _________________.
o ________ Horizon: the _______ layer of soil.

Because there is less _____________ matter in this horizon, it is
_____________ in color than A Horizon.

Contains materials from A horizon that were moved down by
_________________: the removal of ___________ that have been
________________ in water. Water reacts with ____________
and carbon dioxide to form ____________. The acid dissolves the
_______________ in ____ horizon and carries them to ______
horizon.
o ________ Horizon: the ____________ of the soil profile.

Consists of partially _________________ rock.

The ___________ soil horizon.

Does not contain much _____________ ___________ and is not
affected by ___________________.


The soil layer that is the most like the ______________ material.
At many places on Earth, land is covered by a thick layer of ______________ that
was deposited by _________________.
o This material is an unsorted mixture of _________, __________,
__________, and _______________ that was left after the glacial ice
melted. It is extremely __________________.
Soil Types

Many different ____________ of soil exist, based on ______________ and
_______________.

Desert soils are _____________ and have little _____________ matter.

Prairie soils have thick, dark ______ horizons because of the grasses contributing
lots of ____________ _______________.

_______________ also affects soils.
o Steep slopes have _____________ soils because material moves downhill
before it can be weathered.
o Bottomland soils are _________ , _________, and full of organic matter
because sediment and water are plentiful.