1) Sedimentary rocks form when sediments from eroded and weathered pre-existing rocks are transported, deposited, and lithified. 2) Sedimentary rocks can be classified based on grain size as argillaceous (clay), arenaceous (sand), or rudaceous (gravel/cobbles). They can also be classified based on origin as mechanical, chemical, or organic. 3) The key processes in sedimentary rock formation are erosion, transportation of sediments by water, wind or ice, deposition of sediments, and their transformation into rock through compaction and cementation.

1. APPLIED GEOLOGY
NAME:MUHAMMAD UMAR SHAIKH

2. CONTENTS
SEDIMENTARY ROCK FORMATION OF SEDIMENTARY ROCK IT’S CLASSIFICATION

3. SEDIMENTARY ROCK
What is Sediment?
Sediments are loose material such as rock
fragments, mineral grains, and remains of some organisms.
Sedimentary Rock:
• Sedimentary rock are derived from the Latin word
“Sedimentum” means “Settle Down”.
• A rock that has been derived through pre-existing rock by
the process of Erosion,Transportation and Deposition by
natural ageries such as wind water.
• Sedimentary rock forming the earth crust cover about
75% of the continental area nearly 100% of the oceanic
floor..

4. FORMATION OF SEDIMENTARY ROCK
• Sedimentary rock account for approximately 5% of the
crust. The upper 16Km of Earth.
• Regardless of this low percentage, approximately 75% of
all rocks exposed at the surface is Sedimentary rock .
• Factors leading to the formation of sedimentary rocks
include;
1. Erosion and Weathering
2. Transportation
3. Deposition
4. Transformation of the deposited material.

5. EROSION AND WEATHERING
• In reference to the Rock Cycle, the origin of
sedimentary rock begins with the processes of
Weathering and Erosion.
• Pre-existing rocks can be broken down both
mechanically or chemically to produce Sediment.
Mechanical Weathering:
• Mechanical Weathering happens when a Material
is broken into smaller pieces still retain the
characteristics of original material. Example: freeze
– thaw action

7. CHEMICAL WEATHERING
• Chemical Weathering happens
when a material is altered by
chemical action and a new
material is produced which is
chemically different than the
original material.
• Examples: Statues and
headstones

8. TRANSPORTATION OF SEDIMENT
• Erosional agents (such as; wind, water & Ice,)
influenced by gravity, transport the Sediment to
new locations where it is deposited.
• Sediment is broken down during the Transport
phase. This process is called Abrasion.
• Three main agents tend to transport the Sediment,
these being;
1. Water (Rivers and groundwater)
2. Ice (Glaciers)
3. Wind

9. DEPOSITION OF THE MATERIAL
• The eroded material which is
transported by the
transporting agents is
deposited sooner or later
depending upon the
circumstances. These
Sediments continue to
accumulate in suitable basins
of sedimentation.

10. TRANSFORMATION OF THE DEPOSITED MATERIAL
• After Sometime when the accumulation is sufficient, the loose
rock particles are subjected to compaction (sometime due to
overlaying Sediments or earth movements) And finally conversion
into sedimentary rocks, under favourable circumstances. The
process pf transformation of loose rock particle into hard and
massive sedimentary rock is achieved through the the following
two ways:
• (i) Welding
• (ii) Cementation

11. WELDING & CEMENTATION
• Welding: Sometimes the Sediments are compacted under the
Influence of pressure. As a result of the compaction, the water
present in the Sediment is squezed out. This process invariably
result in a very dense packing of the sediments, which are firmly
held together; as if they are subjected to welding.
• Cementation: Sometimes the sediments are Held together by a
foreign binding or cementing material (as the stone chip are held
together by the cement mortor). This cementing material is
generally supplied by the percolating waters.The most common
cementing materials are carbonates pf calcuim and magnesium as
well as oxides of iron and silicon.

12. CLASSIFICATION OF SEDIMENTARY ROCKS
• The sedimentary rock have been classified by different scientists
on different bases. But there is no definite classification, which
may be accepted universally. The following two classification are
important from the subject point of view:
1. Classification based on the grain-Size of the sediments of the
rocks.
2. Classification based on the mode of formation or origin of the
rocks.

13. CLASSIFICATION BASED ON THE GRAIN-
SIZE OF THE SEDIMENTS OF THE ROCKS.
• Sedimentary rocks may be classified on the basis of
grain-size of their sediments into the following three
groups:
1.Argillaceous
2.Arenaceous
3.Rudaceous

14. 1. Argillaceous:
Argillaceous (Latin, arigilla=clay) are those sedimentary
rocks which are made up from the finest clay particles.
2. Arenaceous:
Arenaceous (Latin, Arena=Sand) are those
sedimentary rock which are made of particles, having grain size
between 1/10 mm and 2 mm in diameter.
3. Rudaceous:
Rudaceous (Latin, Rudnus=rubble) are those sedimentary
rock which are made of particles, having grain size more than 2 mm
in diameter.

15. CLASSIFICATION BASED ON THE MODE OF
FORMATION OR ORIGIN OF THE ROCKS.
• Sedimentary rocks may be classified on the basis of
their mode of origin into the following three
groups:
1.Mechanical Origin
2.Chemical Origin
3.Organic Origin

16. 1. Mechanical Origin:
All those sedimentary rocks, which are derived from the pre
existing rocks by the mechanical action (disintegration i.e; fraction and abrasion,
Transportation , Deposition amd consolidation) of the denuding agents, without
any change in their chemical composition, are called sedimentary rocks of
Mechanical Origin.
2. Chemical Origin:
All those sedimentary rocks, which are derived from the pre
existing rocks by the chemical action (decomposition, precipitation
crystallization, etc) of the denuding agents, are called Sedimentary rocks of
Chemical Origin.
3. Organic Origin:
All these sedimentary rocks, which are derived from the pre
existing rocks by the activities of the organisms (Both plants and animals) are
called sedimentary rocks of Organic Origin.