This PPT about Sedimentary Rock Classification of Clastic and Non-Clastic Rocks; Its tells about the origin and Types...

1. Annamalai University
Department of Earth Sciences
M.Sc.Geology Int
Batch(2016 – 2021)

2. CLASTIC AND NON-CLASTIC
SEDIMENTARY ROCK
Presented by
1.N.Giridharan
2.T.Gokul
3.M.Gopinath
4.C.V.Haribalaji
5.Ibrahim Ali Hirad

3. Sedimentary Rocks
The sedimentary rock was classified into two types:-
 Detrital Rock (Clastic rock)
 Chemical Rock (Non-Clastic rock)

4. Clastic sedimentary rocks:
Clastic sedimentary rocks are the rocks composed predominantly of
broken pieces or clast of older weathered and eroded rocks. These
particles are that have been packed together with spaces between grains
(pores). Later these pores are filled with cementing materials such as silica
or calcite etc. deposited by groundwater moving through these
sediments. Eg. Sandstone and conglomerate.

5. Clastic Rocks

6. Clastic Rocks
Clastic Sedimentary rocks are named according to the grain size
of the sediment particles.
Example:
Conglomerate: Coarse (64mm to > 2mm) rounded grains.
Breccia: Coarse (64mm to > 2mm), Angular grains.
Sandstone: grains ranging in size from 2mm to 1/6mm.
Shale: grains ranging from less than < 1mm.

7. Grain Size of Clastic Rocks

8. Clastic Rocks
The Nomenclature of clastic sedimentary rocks is given by the following
rules:
 Sandstone is composed of >50% sand sized particles. The mineral
composition is dominated by quartz and feldspar.
 Siltstone is composed of >50% silt sized particles; they are generally
less rich in quartz than is sandstone.
 Claystone is composed of >50% clay sized particles; they are generally
formed by clay minerals.

9. Clastic Rocks
 Classification of Clastic Sedimentary Rock(Pettijohn
1969)
Clastic
rock
Rudecous Rock
(Coarse grain
>2mm)
Argillaceous Rock
(Medium grain
1/16 – 2mm)
Arenaceous rock
(fine grain
<1/16mm)

10. Clastic Rock
Rudaceous rock:
These include all coarse grained clastic rock of heterogeneous
composition
Made up of rounded or sub-rounded pebbles – cobbles (Conglomerate)
and angular to sub-angular pebbles cobbles (Breccia)
Example:-
1.Conglomerate
2.Breccia

11. Conglomerate
It is consist rounded fragments of various sizes, but generally above 2mm.
Conglomerate rock is a sedimentary rock formed from rounded gravel and
boulder sized clasts more than 30% by volume cemented together in a
matrix.
A Conglomerate in which clasts are exotic(i.e., derived from outside the
depositional basin). Clasts are normally very well rounded and well sorted
as they have been transported for longer distance.

13. Characteristics of Conglomerate:-
 Rounded clasts.
 Unique clast composition.
 Uniform clast-size.
 Chaotic clast orientation.

14. 1)Extraformational Conglomerate:-
These rocks are characterized by the presence of clasts that have a very
different composition as that of the cement or matrix. This indicates that
they have formed in a different environment and were transported to a
completely different area, where the cement was formed. For example:
basalt clasts embedded in calcareous matrix

15. Extraformational Conglomerate:-

16. Conglomerate
a)OrthoConglomerate:-
Conglomerate may have no matrix between clasts(open framework)
or spaces between clasts may be filled by less than 15% matrix of finer
sediment (closed Framework)

17. Orthoconglomerate

18. Conglomerate
b) Para conglomerate:-
Conglomerate which most clasts are not in contact; i.e., the matrix supports
the clasts which is more than 15%
Oligomictic Conglomerate:-
A conglomerate in which the clasts are made up of only one rock type.
Suggest that the source area was nearby and have one or similar source rock.
Polymictic Conglomerate:-
Conglomerates that include clasts from a wide-variety of source rocks,
possibly derived over a wide geographical area or a smaller but geologically
complex area.

19. Para Conglomerate

20. Oligomictric Conglomerate

21. Polymictric Conglomerate

22. Conglomerate
2) Intraformational Conglomerate:-
 A conglomerate in which clasts are derived locally from
within the depositional basin (e.g., clasts composed of
local muds from up by currents; such clasts are commonly
termed “rip-up clasts” or “mud clasts”).
 Deposition in an environment where muds accumulated.
Muds were in very close proximately to the site of
deposition as the class would not withstand considerable
transport.

23. Intraformational Conglomerate

24. Clastic Rock
2.Breccia:-
If grains are Angular, the rock is termed as ‘Breccia’
Grain Size – 2mm to several cm, in finer matrix.

26. Breccia
 Origin of Breccia:-
Parent
Rock or
Magma
Volcanic or
Pyroclastic
Tectonic or
Cataclastic
Breccia
Founder or
Epiclastic
Breccia
Impact or
Fall back
Breccia

27. Pyroclastic or Volcanic Breccia
Pyroclastic or Volcanic Breccia
The rock was composed solely or
primarily of volcanic materials Where
the volcanic material has been
transported and reworked through
mechanical action, such as by wind or
water, these rocks are
termed volcaniclastic.

28. Cataclastic or Tectanic Breccia
The Cataclastic breccia its type of
cataclastic rock formed by
mechanical deformation. It’s is a type
of fault rock that has been wholly or
partly formed by the progressive
fracturing and comminution of
existing rocks, a process known
as cataclasis. Cataclastic rocks are
associated with fault zones
and impact event breccia.

29. Epiclastic Breccia
The epiclastic breccia was
formed by transportation of
loose volcanic material by
epigenic geomorphic
agents or by gravity

30. Impact Breccia
Impact breccia, a type of
impactite, forms during the
process of impact cratering when
large meteorites or
comets impact with the Earth or
other rocky planets or
asteroids. Breccia of this type may
be present on or beneath the
floor of the crater

31. Clastic Rock
 ARGILLACEOUS ROCKS:-
Made up of clay size sediments. This is fine grained rock and grain size
1/25mm to 1/64mm.
Example:-
1. Shale
2. Mudstone
3. Claystone

32. Clastic Rock
Shale:-
 Shales are clastic rocks, made up mainly fine slit/clay
 They are most abundant sedimentary rocks, accounts for about 80% of them
 Often contain fossil
 Mostly hydrous aluminium silicate in composition from weathered feldspars
Shale = Quartz + Feldspar + Mica
 Shales are made of fine well sorted silt and clayey sediments, where normally one can
expect high porosity and permeability.

33. Shale

34. Clastic Rock
Mudstones:-
A grey or black rock formed from mud, mudstone contain both detrital minerals,
such as quartz, feldspar, clay minerals and carbonaceous matter. Individual
grains, however are too small to be seen without a hand lens. Some mudstones
are fossiliferous, others are calcareous and react with acid.
 Grain Size- Less than 0.1mm.
 Essential components Quartz and Feldspar

35. Mudstone

36. Clastic Rock
Clay stone:-
Clay is typically dark to light grey a pure white variety called china clay can
occur, individual grains may be seen only under powerful microscopes.
Grain Size – Less than 0.005mm.
Essential Components – Clay Minerals, such as Kaolinite, Illite

37. Claystone

38. Clastic Rock
ARENACEOUS ROCK:-
Made up of mainly sand e.g. sandstone. These rocks are either accumulated by wind
action or deposited under water action or marine to non marine. This rock is medium
grained and grain size 1/16mm to 2mm.
Example:-
1. Sandstone
2. Silt stone
3. Arkose
4. Greywacke
5. Grit

39. Clastic Rock
Sandstone:-
One of the most common sedimentary rocks, sandstone is
usually quartz dominated with visibly sandy grains.
Grain Size – 0.1 -2mm.
ESSENTIAL COMPONENTS – Quartz and Feldspar.
ADDITIONAL COMPONENTS – Mica and many others.

40. Sandstone

41. Classification of Sandstone
Sandstone
Siliceous
Sandstone
Silica (Sio2) is
Cementing
material
Calcareous
Sandstone
In Cemeting
Material is CaCo3
& Mg
Argillaceous
Sandstone
Cementing
Material is Clayey
in character
Ferruginous
Sandstone
Cementing
material is fe
composition

42. Siliceous Sandstone

43. Calcareous Sandstone

44. Argillaceous Sandstone

45. Ferruginous Sandstone

46. Clastic Rock
Siltstone:-
Siltstone is another detrital sedimentary rock, lying in grain size between
sandstone and mudstone. Like sandstone, it can form in different environments
and have different colours and textures, but reds and greys, and planar bedding
are typical. Plant fossil and other carbonaceous matter are common in darker-
coloured siltstones. The presence of mica may produce a flaggy siltstone.
GRAIN SIZE 0.1-2mm.
ESSENTIAL COMPONENTS – Quartz and Feldspar.
ADDDITIONAL COMPONENTS – Mica and many others

47. Siltstone

48. Clastic Rock
 Arkose:-
A pink sandstone the colour of which is due to an abundance of feldspar,
especially pink alkali feldspar. Arkose forms by the fast deposition of sand
weathered from granites and gneisses
GRAIN SIZE – 0.1-2mm.
ESSENTIAL COMPONENTS – Feldspar and Quartz.

49. Arkose

50. Clastic Rock
 Greywacke:-
 Greywacke has formed from a mixture of sand and, proportionately less,
mud. It is a dark-coloured rock (grey, dark green or black) containing.
 Poorly sorted angular fragments of quartz and basic igneous rock and fine
grained chlorite or clay mineral.
 Greywacke may contain as much as 30% fine grained clay or chlorite or
both.
 GRAIN SIZE 0.005 – 2mm.
 ESSENTIAL COMPONENTS – Rock and Mineral fragments

51. Greywacke

52. Clastic Rock
 Grit or Grit stone:-
Grit is a hard, coarse grained rock, siliceous sandstone.
It is a sandstone containing sharply angular grain that may rub off
early.
Most of the grit are formed in water,
The chief miner components are quartz, feldspar and mica
This term is especially applied to such sandstone that are quarried
for building material.

53. Grit Stone

54. Non-clastic sedimentary rocks
Non clastic sedimentary rocks form from both chemical and
biological process. Based on these it is divided into two types: organic
sedimentary rocks and chemical sedimentary rocks.
 Organic sedimentary rocks:
It is formed from the remains from the plants and animals. It
includes limestone and coal. Limestone forms in warm, Clearwater as a
result of marine organisms which synthesize the calcium carbonate for their
shells and exoskeletons. When they die calcium minerals that pile on the
sea floor over a long time to form limestone.
Some of these rocks are also found on land. Eg coal.

55. Biogenic Sedimentary Rocks
 Carbonates made of CaCo3 ( Calcite or Aragonite) are called Limestones
 Carbonates made of CaMgCo3 (dolomite) are called dolostones and are
often the result of post-depositional substitution of limestones
 Most carbonated are biogenic, the bulk produced by algae and shelled
protists (single called eukaryotic organisms) + Coral + mollusks
 Some are precipitated(e.g. tufa)
 Most carbonates are marine
 Chalk is a very fine-grained limestone mostly made from the shells of
photosynthesizing nanno-plankton called coccolithophores.

56. Biogenic Sedimentary Rocks
 Already noted chert (microcrystalline quartz sediment of the formed from
diatom and radiolarian skeleton) Chalk( fine carbonate sediment formed from
coccolith and foraminifera skeletons) where no clastic deposition.
 Also coal formed from dead plants in anoxic swamps
 First Peat Lignite Brown Coal Bituminous coal
Anthracite with increased burial (increasing coal rank)
 Composed of maceral from different plant organs

57. Biogenic Sedimentary Rocks

58. Biogenic Sedimentary Rocks

59. Biogenic Carbonates Rock
 Several carbonate classification schemes but Dunham’s perhaps most useful
 Alsordule(Coarse) Arenite(Sandy) Jutite(muddy)
 Most limestones are skeletal made up of the calcium carbonate skeletons of
marine animals and algae
 Skeletons may be cemented to the substrate forming biochemical (mounds
rising above sea-floor) boundstone e.g. coral reefs
 More often, skeletons are fragmented forming grainstone

60. Microbial Carbonates
 Cyanobacteria and other microbes can precipitate carbonate or trap lime
mud, forming stromatolites of layered and attached thrombolites unlayered
of concoidal unattached.
 Photosynthesis remove Co2 increasing carbonate saturation causing
precipitation, cementation

61. Limestone
Limestone is a Sedimentary rock composed primarily of calcium carbonate
(CaCo3) in the form of the mineral calcite. it most commonly forms in clear,
warm, shallow marine waters.it is usually an organic sedimentary rock that forms
from the accumulation of shell, coral, algal and fecal debris. It can also be a
chemical sedimentary rock formed by the precipitation of calcium carbonate from
lake or ocean water.

62. Origin of Limestone:-
 Limestones may be deposited in seas, lakes, rivers and on the lands.
 Circulation and presence of land derived detritus, such as arenaceous,
argillaceous and ferruginous materials are factors of importance.
 Certain forms, such as algae, foraminiferas and corals are important rock
builders, while others are rarely so.
 Limestones may also form through evaporation.

63. Limestone
Fossiliferous Limestone Limestone Reef

64. Texture of Limestone:-
 The texture of limestone are variable and unequalled by any other group of rocks.
 Some are clastic(cementation of sand and/or mud by Calcite)
 Others result from processes of organic acceration
 Others are formed by post depoditional changes
 Some are coarsely crystalline, and others fine-grained or even aphanitic
 Ooilitic or pisolitic (chemically deposited limestone)
 Consist of carbonate grains all of uniform size, whereas other are molted large
crystals scattered through a matrix of finer grains
 Porous (owing to Algal structures)
 Other carbonate structure are so interlocked.

65. Ooilitic Limestone

66. Chemical Sedimentary Rocks:-
It is formed from the precipitation of chemicals in water. In order
for precipitation to occur, the water must be super saturated with
chemical substance.
Chemical precipitates are also play major role as cementing agent for the
coarse grained clastic rocks.
 Evaporites :-
It is also one of the types of non-clastic sediments. It is formed by
the evaporations of saline bodies of water.
Eg. Common salt

67. EVAPORITES
As a body of sea water or a saline lake experiences net evaporation, the
concentration of the ions dissolved in that water rises until the saturation
point of various materials is exceeded, and minerals precipitate or crystallize.
Many of these minerals are economically significant, such as gypsum, halite,
and potash salts from sea water, and epsom salts, borax and trona from
saline lakes. The first minerals to form as the water evaporates are
carbonates, which we have covered already under biochemical sedimentary
rocks. They are generally volumetrically minor components of evaporite
mineral assemblages.

68. Evaporites

69. Gypsum.
This is
hydrated
calcium
sulphate; the
sulphates are
the second
major group to
form as sea
water
evaporates.
Such large crystals as these are frequently formed by precipitation
from saturated groundwater circulating through near-surface
sediment deposits and soils, rather than precipitation from sea water.
Note the clarity of these large crystals, which have a Mohs hardness of
2.

70. Gypsum – the Effect of Crystal Size
Both photos illustrate the effect on opacity that crystal size has.
These evaporite samples consist of thousands of individual small
crystals, whose edges and grain boundaries dominate the optical
effects and render the samples opaque, even though gypsum is
transparent to translucent. The right sample is from the Devonian
age Elk Point Group of the Western Canada Sedimentary Basin.

71. Anhydrite.
This is calcium
sulphate
without the
bound
molecular
water that
defines
gypsum.
In this sample
it is white.
This is less likely to form as a primary evaporite mineral, because the
presence of water makes gypsum formation more likely. It is
possible to dehydrate gypsum after its initial formation, or as
apparently happened in this case, for anhydrite to form in a
carbonate host rock.

72. Thank You, Ciao..!!!