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1. SEDIMENTARY ROCKS
GROUP 1

2. What is Sedimentary
Rocks?
• Sedimentary rocks are formed
on or near the Earth’s surface,
in contrast to metamorphic and
igneous rocks, which are formed
deep within the Earth. The most
important geological processes
that lead to the creation of
sedimentary rocks are erosion,
weathering, dissolution,
precipitation, and lithification.

3. EXAMPLE:

4. • These are formed at near the surface of
the Earth through SEDIMENTATION.
 SEDIMENTATION is the tendency for
particles/sediments to settle in a fluid.
• The factors which contributes to the
occurrence of sedimentary processes are
the LOW TEMPERATURE AND
PRESSURE at the Earth’s surface.
• These Rocks are classsified into
three:
 CLASTIC
 NONLASTIC

5. CLASTIC
SEDIMENTARY ROCKS
are composed of pieces of
pre-existing rocks, grains,
and cements that are
glued together.
This subgroup of rocks
are classified based on
their particle size.

6. NONCLASTIC
SEDIMENTARY ROCKS
• are formed be chemical reactions giving these rocks
organic origins.
• Evaporites, Precipitates, and Bioclastics are the
classification of these rocks.
• EVAPORITES - are rocks formed when water
evaporates leaving the dissolve minerals to
crystallize.
• PRECIPITATES - are rocks formed when minerals
from a mineral supersaturated waters start to
crystallize at the bottom of the solution.
• BIOCLASTIC/ORGANIC sedimentary rocks - are
formed when campacted organic matter undergoes
compaction and cementation.

7. Before we end up this discussion we will know first the overview
on how the sedimentary rocks are formed. Kindly check the
following illustration.
Weathering has two major parts:
1. Mechanical Weathering/Disintegration
 processes that break a rock or mineral into smaller pieces
without altering its composition.
• This type of weathering would produce Clastic
Sedimentary Rocks.
2. Chemical Weathering/Decomposition
 processes that change the chemical composition or rocks
and minerals.
• Oxygen gas is seen to be agent of this type weathering as
it oxidize rocks when mix with water.
• This type of weathering would lead to the formation of non
clastic rocks.

8. • Water, wind or ice are seen to be the agent
of erosion.
• If the wind is dusty, or water or glacial ice
is muddy, erosion is taking place
• Bits of rock and soil are suspended in the
fluid (air or water) and being transported
from one place to another. This transported
material is called SEDIMENT.

10. These are the processes involved in the
formation of SEDIMENTARY ROCKS.

11. These are the processes involved in the
formation of SEDIMENTARY ROCKS.
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YOU