Rocks, Minerals, and Soil
http://techalive.mtu.edu/m
eec/module10/Decomposit
ion.htm
Minerals
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Minerals are ‘ingredients’
of rocks
There are over 3,000
known minerals in the
world
*
Properties
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We use many different kinds of words to describe and
sort rocks including:
Color
 Luster (dull or shiny)
 Texture
 Hardness
 Transparency
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Igneous Rocks
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Obsidian
Granite
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Basalt
*Google images
Igneous means made from
fire or heat
There are two major types of
igneous rock; extrusive and
intrusive
Extrusive is created when
magma comes to the earth’s
surface and becomes lava.
When lava cools, it becomes
rock, such as obsidian
Intrusive like granite is formed
inside the earth’s crust when
magma hardens
Sedimentary
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http://www.fi.edu/fellows/fellow1/oct98/create/sediment.htm
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*Google images
Large rocks break down into
smaller rocks and sand
(sediment)
Over time, this sediment
settles to the bottom of bodies
of water and creates
sedimentary rock due to time
and pressure
Fossils are found in
sedimentary rocks
It can often be identified by its
layered or conglomerate
design or sandy texture
Metamorphic
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Gneiss
Marble
*Google images
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Metamorphic means to
change form
They are created when
sedimentary and igneous
rocks are heated, squeezed
and folded during movement
of the earth’s crust
Marble is a metamorphic rock
Banding and layering can
occur; they are the least
common of the three kinds of
rocks
Soil
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Soil is made of:
-air and water
-living organisms
-organic matter ( leaves,
grass, twigs, roots)
-rocks and minerals
-decomposed plants and
animals
Soil is different from place to
place because of weather and
climate, parent material, and
organisms.
How is soil created?

Soil is created over
time by:
-rocks and minerals
breaking down;
weathering and
erosion: wind, water,
chemical, ice, plant
-decomposition
Three Types of Soil
Clay
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Silt
Sand
Clay
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There are three types of soil,
and they are classified by
their texture and particle size.
In clay, particles are small
and they clump together.
When wet, clay soil feels like
modeling clay.
Clay doesn’t drain water very
well because it is packed
together tightly.
Silt
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Silt has smaller particles
than sand, but larger
particles than clay.
Silt’s texture is similar to
that of flour, powdery.
It is the darkest and
loosest of the three soils.
Sand
- www.rain.org
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Sand has the largest
particles (like sugar).
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Its texture is gritty.
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It has the best ability to
drain water out of all
three types of soil.
Soil Profile
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O: Organic Matter
A: Topsoil (loam)
E: Subsoil- mostly silt
and sand
B: Subsoil- mostly clay
C: Parent Material
R: Bedrock
What if there was no soil?
Without soil we wouldn’t have blue jeans! Jeans are
made of cotton denim stitched together with cotton
thread. Their blue color comes from indigo dye.
Cotton and indigo come from plants that need soil to
grow. If we did not have soil healthy soil the plants
necessary to make jeans would not exist!