Download Sedimentary rocks

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1. Wind , water, ice, sunlight, and gravity
all cause rock to physically weather into
fragments.
2. Through the process of erosion, these
rock and mineral fragments, called
sediments, are moved from one place to
another.
3. eventually , the sediment is deposited in
layers.
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4. As new layers of
sediments are
deposited, they cover
the older layers. The
older layers become
compacted.
2. Organic
sedimentary rock
forms from the
remains of once-living
plants and animals.
 Some limestone is
made of the skeletons
of tiny organisms
called coral. They are
small but live in
colonies called reefs.
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 . 3. Chemical
sedimentary rocks
form when minerals
crystallize out of a
solution, such as sea
water, to become a
rock.
They form from
solutions of dissolved
minerals and water.
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The skeletons of sea
animals which are
made of calcium
carbonate, collect on
the ocean floor.
These animal remains
eventually become
cemented together to
form fossiliferous
limestone.
Another type of
sedimentary rock is
coal.
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Coal forms
underground when
partially decomposed
plant material is
buried beneath
sediment and is
changed into coal by
increasing heat and
pressure.
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The most important
feature of sedimentary
rocks is stratification.
Stratification is the
process in which
sedimentary rocks are
arranged in layers.
Strata differs from one
another depending on
the kind, size, and color
of sediment.
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Sedimentary rocks sometimes record the
motion of wind and water waves on lakes,
oceans , rivers, and sand dunes in features
called ripple marks.
Structures called mud cracks form when
fine grained sediments at the bottom of a
shallow body of water are exposed to the
air and dry out.