Transcript Geology

Gujarat Institute of Technical
Studies
Name: Pandya Drupad P.
Semester: 3st Sem.
Branch: Civil Engineering
Enrollment No. :130620106003
Topic: geology
1. Geology
Geology = Earth Science
What is the meaning of geology ?
Geology is the study of Earth, includes, Chemical and Physical
Properties, Earth Creation, Inner and Outer Processes Affected it,
Since Its Creation To Present Day.
Geological Branches
A-Basic geology:1- Crystallography .
B-Connected Branches:1- Geochemistry.
C- Applied Geology:1-Economic Geology.
2- Mineralogy.
2- Geophysics.
2-Engineering Geology.
3- Petrology .
3-Geomorpholpgy.
3-Petroleum Geology.
4- Paleontology .
4-Structural Geology.
4-Hydrogeology.
5- Stratigraphy .
5-Photogeology.
5-Mining geology.
6- Dynamic geology .
6-Oceanography.
6-Agricultural geology.
7- Historical geology .
7- Field geology. 33
7-Miltary geology.
8-Glacial geology.
9-Volcanology.
10-Cosmic geology.
11-Geodesy.
The relationship between geology and other sciences
1-Physics ----------- Geophysics ---------- 1-Gravity Method.
2-Magnetic Method.
3-Seismology.
4-Electrical Method.
2-Biology --------------- Paleontology ------Remaining of Animals and Botanical.
3- Chemistry ----------- Geochemistry.
4-Engineering ---------- Engineering geology.
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The site of Earth within Galaxy (Milky Way)
D = Day
Y = Year
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4
Nature of Earth
A-Dimensions of Earth :1-The polar Radius =6357 kilometre .
2-Equator Radius =6378 kilometre .
3-Polar Circumference = 6357 km x 2 x 22 ÷ 7 = 40 009 kilometre .
4-Equator Circumference = 6378 km x 2 x 22 ÷ 7 = 40 077 kilometre .
5-Area of earth surface = 510 000 000 square kilometre.
7-Dry area of earth surface = 29,22% = 149 000 000 square kilometre.
8-Water area of earth surface = 70.78% = 361 000 000 square kilometre.
9-highest point of dry area at earth surface = 8848 metre (Everest mountains crest).
10-Avverage of earth surface = 840 metre.
11-deeper point of ocean = 11033 metre (Mariana trench).
12-Average of ocean deep = 3808 metre.
Polar Dimension
Equator
5
7
C
R
O
S
S
S
E
C
T
I
O
sial
5 - 60 km Crust
5 - 60 km
sail
Crust
0C
Sima
Sima
870 C
Upper Mantle
Conrad Discontinuity
Conrad Discontinuity
Peridotite Rocks
Moho Discontinuity
Moho Discontinuity
Peridotite Rocks
Mantle
35 - 2900 km
Mantle
Lower Mantle
Pallasite
Rocks
(peridotite=Fe
) ()
Gutenberg Discontinuity
2 200 C
Gutenberg Discontinuity
2900 km
Upper Core
Upper Core
Fe = 90%
Ni = 10%
N
I
N
E
A
R
T
H
2900 - 6370 km
Core
Earth Crust Density= 2.85 gm/cm3
Lowe Core
Core
Iron+Ni
Lower
Core
Mantle Density = 4.53 gm/cm3
Core Density= 10.7gm /cm3
6370 km
6 000 C
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Earth Covers
1-Atmosphere cover.
3-Biosphere cover.
2-Hydrosphere cover.
4-Lithosphere cover.
1-Atmosphere cover :-It is Air cover, surrounding Earth. Its thickness about 316 km . atmosphere is consist of many Gases like :a- N2
about
78%
b- O2
about
21%
c- Ar
about
0.93
d- CO2 about
0.03%
e- H2
about
0.011
99.124%
About 35 PPM are inactive Gasses such as Neon, Helium and Ozone are present in Atmosphere .
1-Atmosphere Cover:-Atmosphere cover is divided into:A-Troposphere layer :1- Elevation of Troposphere layer is about 8 - 18 km .
2- Temperature is decreasing about 6 ْC every 1 km
rising
3-This layer is consist of homogenous gases, water
vapour, CO2 and dust.
B-stratosphere layer :1- The second layer with elevation about 50- 80 km .
2- The lower part of this Layer is (50 km) named
Ozone layer .
3- Stratosphere temperature is increase to 35 ْC with
no storm.
4- Stratospheric Pressure is 0.5 mm mercury (1/1520) of
Normal Pressure.
C-Ionosphere Layer:1- The elevation is about 80 – 316 km
2- the Ionization is due to the affects of the Cosmic and Ultra violent
Rays, so it is good Conductor for Electricity.
3- Many of (Meteors and Meteorites)are Burn with Traffic in this Layer.
4- This Layer is Good medium to cross Radio and Wireless Waves.
D-Exosphere layer :The highest layer in the Atmosphere ,so it is extend as far as entrance of outer
space .
Meteor:It is Solid, Small masses swimming in the space, but when it
falls on the Earth it called (Meteorites).
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Earth Crust – sial and Sima Layer
Sial Layer:-It is the upper part of Earth crust .Its thickness between 2-15 km, Density about 2.8gm /cm3 .
Sail is consist of light colours Granitic Rocks ( Aluminium Silicate).
Sial Layer is thick at Land while it is thin or absent at Oceans.
Sima Layer:-It is the lower part of Earth Crust. Its thickness about 20-25 km, Density about 3.4gm /cm3 . Sima consist of Magnesium
Silicate. The upper part of this layer is Crystalline but the lower part is uncrystalline (classy texture).
Conrad Discontinuity:- Interference zone which is separated between Sial and Sima.
Sea Level
Conrad Discontinuity
Sial Layer
Sima Layer
Moho discontinuity
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Outer Properties Of Crystals
The properties of Crystal are depend on:1-Crystal Faces:-The Crystals have regular outer planes named (Crystal Faces) A .
2- Crystal Angles:- a-The angle between two neighbor faces is named (Edge Angle) B .
b-The angle between three neighbor faces is named (Solid Angle) C .
c-The angle between two faces is (Interfacial Angle), It can measured by two perpendicular columns on
neighbor and 0pp0site faces C .
3-Crystal Form:- It means groups of Crystals are similar in shape, Area and its Crystal situation. The Crystal can be form of one
shape of faces named (Simple Form) or many shapes named (Compound Form).
A - Faces
C
A
B
Closed Crystal
Face
B - Edges Angle
C - Solid Angle
Interfacial Angle
Faces and angle of crystals
Open Crystal
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2-Evaporation of Assistant Dissolved Gas
Underground Solutions contains dissolved CO2 Gas as a result of Rainfall.
This is result H2CO3 (weak Carbonic Acid), Which is dissolved Limestone and to form Calcium Bicarbonate Ca (HCO3)2.The later is
Chemically unstable. So It is escape CO2 Gas and come back to Calcium Carbonate.
CaCO3+H2O+CO2
Ca(HCO3)2
Ca(HCO3)2 (Deposited Calcium Bicarbonate)
CO2+H2O+CaCO3 (Deposited Calcite)
(1)
(2)
This phenomena is clear in Rainy, Cavities and Limestone Regions, Since Limestone is Deposit in Conical Shape as above
Equation, Named:- Stalactite and Stalagmite.
Mountain
Travertine
CaCO3
Hot Spring
Water Table
Stalactite
Stalagmite
Cave
Aquifer
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Hot Body
Minerals Creation Of Gas
A-Volatiles
Cassiterite (SnO2)
B-Another Minerals
Tourmaline – Topaz
C-Through Volcanic
S - NaCl
Minerals Creation Of Solutions
A-Surface Solutions (Oceans, Seas, Lakes):1-Crystalline Minerals (Evaporation)
Calcite(CaCO3)
Gypsum(CaSO4)2H2O
2-Exchage Reaction (Special Minerals)
Barite(BaSO4)
Minerals Creation Of Magma
A-Magma Hardening:1-Sillicate Minerals
Plagioclase(Na-Ca)AlSi3O8
Olivine(Fe- Mg)SiO4
Quartz(SiO2 – Mica
2-Oxide Minerals
3-Creature Affected
1-Coral (Extract – CaCO3)
2-Foraminefra (Extract – Si)
3-Bacteria (Absorbed –Fe – S)
B-Underground Solution:1-Hydrothermal Solutions
a-Hypothermal Solutions (Walframi Fe,Mn)WO4 Cassiterite (SnO4)
Magnetite(Fe3O4)
Chromite(FeCr2)O4
3-Sulfide Minerals
Galena (PbS) – Pyrite(FeS2)
B.-Lava Hardening.
Obsidian (Complex Rocks)
b-Mesothermal Solutions
Galena- PbS – Sphalarite – ZnS
c-Epithermal Solutions
Quartz- SiO2 – Cinnabar- FeS2
2-Evaporation Of Assistant Dissolved Gas
Stalactite – Stalagmite CaCO3
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4-Isomorphism:-It means two minerals are different in chemical composition and similar in crystal shape. It is series of minerals which is create
through replacement between two atoms almost are equals radius like sodium (Na) and calcium (Ca) to consist a Plagioclase Series. It
Crystallized in Triclinic system.
Plagioclase Series
Albite %
Anorthite %
1-Albite
2-Oligoclase
3-Andesine
4-Labrodorite
5-Betonite
6-Anorthite
100 - 90
90 – 70
70 – 50
50 – 30
30 – 10
10 - 0
0 -10
10 – 30
30 – 50
50 -70
70 – 90
90 - 100
NaAlSi3O8
CaAl2SI2O8
Plagioclase Series is different in chemical composition, So it has graduation of physical properties at two end sides.
5-Pseudomorphism:- It means mineral has constant atomic building and chemical composition while its outer shape like another mineral
such as Pyrite(FeS2) may be change to the Gothite Mineral(FeO2) but the later is still has the same outer shape of Pyrite.
Classification of Minerals:-There are many kinds of Classification:A-Economic Classification :- It depend on Economic Value of Mineral like Diamond, Gold, Platinum and Silver, Cupper and Lead, Zinc.
B-Crystal Chemistry:-like Chemical Bonds, Co-Ordination Number and Isomorphism.
C-Similar Basic Ions:-Depend on Basic Ions Consist Minerals such as:1-Minerals Group contains Iron (Fe):- (Hematite-Fe2O3) (Magnetite Fe3O4)
(Pyrite-FeS2)
(Limonite-FeO(OH)nH2O.
2-Minerals Group contains Cupper (Cu):- (Chalcopyrite-CuFeS2) (Borenite- Cu5FeS4) (Anargite-Cu3AsS4) (Chalcosite Cu2S).
3-Minerals Group contain Lead (Pb):- (Galena-PbS)
4- The best Classification for Minerals is depend on (Kind of Acidic Ions) of J.D.Dana an American Scientist, So Minerals are Classify
into Oxides, Sulphates, carbonates, Phosphates etc.
Note:-More than 2000 Minerals are Known yet.
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ROCKS
Rocks:- It is a Solid substance Consist of one Mineral or Mixture of Minerals.
Earth crust is Consist of:- 1-Igneous Rocks. 2-Sedimentary Rocks.
3-Metamorphic Rocks.
Rocks Cycle
Magma
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D-Classification of Igneous Rocks
Ultra basic
Rocks
Basic Rocks
Blackish Color-Light Density
Basalt
Gabbro
Intermediate Rocks
Andesite
Diorite
Acidic Rocks
Light Color-Low Density
Dacite
Granodiorite
Obsidian
Glassy Texture
Rhyolite
Fine Grains
Texture
Granite
Coarse Grains
Texture
100%
Orthoclase
(KAlSi3O8)
PlagIoclase
(Na,Ca)AlSi3O8)
Quartz
(SiO2)
50%
Olivine
Pyroxene
Ferromagnesium Minerals
Amphibole
Porphyritic texture:-Coarse and fine crystals in the same rocks.
Pumice:-Classy texture with fine spaces as a result of gas escape.
Biotite
Mica
0%
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Shapes of Igneous Masses
Volcano
Sill
Phacolith
Dike
Lacolith
Lapolith
B a t h o l i t h
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E-Classification Of Sedimentary Rocks
Chemical And Organic Sedimentary Rocks
Chemical
Kinds Of
Sedimentary
Rocks
Texture
Chemical
Composition
Mechanical Or Clastic Sedimentary Rocks
Grains Size
Sediments
Rock Name
Rock Name
> 256 mm
Boulders
Conglomerate
Breccia
Clastic or
Non Clastic
CaCO3
(Ca,Mg)CO3
Limestone
Dolostone
2 – 256mm
Gravels
Conglomerate
Breccia
Non Clastic
CaSO4 2H2O
NaCl
Gypsum
Halite
2 – 1 /16 mm
Sand
Sandstone
CaCO3
SiO2 fine
Grains
Remaining of
Vegetable
Organic Lst
Chert
Coal
Organic or
Biological
1 /16 – 1 /256
< 1 /256mm
Silt
(50%Sand+50%Clay)
Clay
Siltstone
Clay stone
Coal Forming Stages :Plants Remaining in Swamps for a long Time
Bury
Anthracite
Beat
Heat and Pressure
Lignite
Bituminous
More Heat and Pressure For a Longer Time
Heat and Pressure for a Long Time
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Faster Wind
Wind Direction
Slower Wind
10ْ
30
ْ
Sand Dune Forming
Figure 2 B
Sand Dunes Forming is a result of reducing at wind velocity. Sand dues are growth around small part (Gravel or Sand) called Nucleus.
Some times it moves to another place with wind direction by way of Sand Dunes Migration. Dunes highest is between (few – many Tens) feet.
Loess Deposits :It is very fine grains (Dust) of quartz, mica, calcite and feldspar with reddish yellow, suspended in air for a long
distance, Then it is descend on earth surface by gravity or rainfall. The typical formation is Loess Area in France.
There are many kinds of Sand Dunes Figure 3 :17
50
1- Barchan (Crescentic) Dunes
4-Star Dunes
Figure 3 Types of Sand Dunes
2—Transvers Dunes
3-Longitudinal Dunes
5-Seif Dunes
6-U-Shape Dunes
Iraqi Sand Dunes
West of Beji – Tikreet
East of Najaf
West of Samawa18
West of Nasiriyah 51
Flood Plains
1-Youth Stage
Properties of Youth Stage:a- the cross section of River at
Youth Stage is V shape.
b- Ability to Grave its Riverbed.
c- Waterfalls are Present.
d- The Branches of River are Short
and Little.
e- It can not be Navigation of Ships
in this Stage.
f- It is Good for Electricity
Generation.
g- Dijla River is represent this stage
from (Armenia Highland) in
Turkey to Mosel City in North Iraq.
2-Mature Stage
Properties of Mature Stage :a- River is More Width and it had
Gentle Slope on both sides, So the
shape of Cross section is like half
Cycle.
b- The Branches is more than Youth
and Longer.
c- Velocity of Water is Moderate, So
it is suitable for Navigation.
d- Area between Mosel and
Baghdad is represent Mature Stage.
Stages Of River
3-Old Stage
Properties of Old Stage:a- River depth and Slope of both
Sides are Little.
b- Low Flow and much Deposits.
c- Flood plain is Present on both
sides of River. so the River was
loosed its Energy for Graving, Thus
the River is begin to Deposits to
form Flood Plain.
d- Meanders are Present in this
Stage.
e- Area between Baghdad and
Basra is represent this Stage.
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2-Hypogene Processes
(Interior Processes)
Hypogene processes means all internal processes which is lead to either a quick processes like earthquakes and volcanoes or slow processes
ike oroginic movement. plate tectonic theory explains this processes.
Plate Tectonic Theory
Plate Tectonic is the study of the origin and arrangements of the broad structural features of earths surface, including not only folds and faults,
but also mountains belt, continents and earthquakes belts.
The basic idea of Plate Tectonics is that, earth surface is divided into eight large Plates plus Few smaller Plates makeup the outer shell of
Earth (Lithosphere). Plates are move slowly With intense geologic activity occur at plate boundary where plate moves away from one another.
Volcano
Convection Currents
Mid- Oceanic Ridge
(Rift Valley at Ridge Crest)
Oceanic Trench
Outer Core
Asthenosphere
Inner Core
(Lower Mantle)
Figure 4 Convection Currents
Lithosphere
(Earth Crust + Upper Mantle)
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A-Quick processes
1- Earth Quakes:- It Is shaking of earth surface, as a result of sudden discharge of energy which is stored in Earths Rock.
strain
Fault Displacement
stress
A
B
Earthquake
C
Figure 4
Figure4 A- Is show rocks under the stress by tectonic forces in the earth.
B- Is show rocks have a bending or deformation shape (Strain).
C-Is show rocks are break with discharge of energy is released as Seismic Waves which causes the earthquake.
The break of earth Rocks is called Fault with move past one another along a fault. Usually, the energy stored in the rocks is more enough to
break the rocks suddenly and making earthquakes. The move of rock through a fault may be vertical or horizontal or both.
There are two idea for faulting:1-Classic (Old) idea:-It must be a very large stress acting to break rocks along a fault because the faults are very hard.
2-New idea:- Fault are weak, so little stress is enough to make rupture then earthquakes.
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Rocks behavior near earth surface is brittle, While at depth it subjected to more temperature
and pressure, which leads Rocks behave to be ductile rocks.
This means there are a limit of depth for faulting. Usually earthquakes are happened with faults displacement, But in some earthquakes are not with
urface faults displacement like earthquakes of eastern united states. Earthquakes also happened during volcanic activity.
Seismic Waves
Epicenter
Focus s
The source of seismic waves is Focus, While
the Epicenter is a point on earths surface vertically above
the Focus Figure 5.
There are two kinds of seismic waves:A- Body Waves:-It is seismic waves travels through
underground rocks in all ways, So it is divided
into two types:1- P-Waves (primary):-In this waves, Rocks are
shaking front and back parallel to direction of P
waves. The properties of this waves are:a-Travel near earths crust at velocity about
6 kilometers per second(figure-6- A).
b- P- Waves is faster than other waves.
c-It is first reaches the station of recording.
d-It can pass through solid, liquid and gas.
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Waves Propagation
Particle Motion
A
A-Primary-W
Expand
Compress
(Figure-7-Surface Waves)
(Figure-6-Body Waves)
B-Secondary-W
Particle Motion
Rayleigh Waves Propagation
B
Waves Propagation
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Constant, Pen Elevation
Moving Up
Normal
Figure 8 Seismograph – Vertical Movement
Moving Down
Hard Tower
Wire
Heavy Weight
Rotating Drum
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Figure 9 Seismograph Horizontal Movement
1-Distance between Epicenter and London :- 4 min x 60 x 6 km /sec =1440 km
2-Distance between Epicenter and Moscow :- 6 x 60 x 7 km /sec = 2520 km
Epicenter
3-Distance between Epicenter and Baghdad :- 11 x 60 x 6 km/sec = 3960 km
Moscow
London
London
Earthquake Time-Minute
25
Moscow
Baghdad
20
11 minute
interval
6 minute
interval
15
Surface
Waves
P
4 minute
interval
10
Baghdad
5
1000
2000
3000
Distance From Epicenter (Kilometers)
Figure 10 Seismogram
4000
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Figure 11 Location of
Earthquakes
2-Volcanoes
What is the Volcano?
When lava is being viscous and spread out of earth body as a flood, Lava is forming a hill or mountains named a Volcano Figure 12.
Table 1 is show characteristic of different type of Volcanoes.
Table 1 Types of Volcanoes
Type of Volcano
Form of Volcano
Size
1-Basalt Plateau
Flat to gentle Slope
2-Shield Volcano
3-Cinder Cone
4-Caldera
Type of Magma
Style of Activity
Examples
Large and thick
Basalt
Gentle eruption from long
fissure
Columbia River
plateau
Slope 2ْ – 6ْ
Up to 9000 m
high
Basalt
Gentle, some fire fountains
Hawaii
Moderate slope
100 - 400 m high
Basalt or Andesite
Ejections of pyroclastic
material
Paricutin Mexico
Cataclysmic explosion
leaving a circular
depression Called
Caldera
Less than 40 km
in diameter
Granite
Very Violent
Yellowstone, San
Juan Mountains
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Figure 12 Volcano Formation
Volcano
Volcano Mountain
Volcano Pipe
Volcano Hill (Extinct)
Lava Flow
Sill
Dike
Plutonic Body
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Spreading Center
Mid - Oceanic Ridge
Sea Level
Lithosphere
(Earth Crust + Upper Mantle)
Oceanic Crust
Magma
Convection Current
Rising Asthenosphere
Figure13– Magma of Spreading Center
3- Magma of Subduction Zone:- The subductinn plate of oceanic crust is saturated with water. Through the subduction, the water forming
stream into hot asthenosphere, As the subduction plate descends oceanic plate is slip asthenosphere rock down with it Figure 15. Rock from the
Deeper part in the Asthenosphere, then flow up word to replace the Sinking Rock, leaving zones of less Pressure at hot Rock rises.
Also Friction between Oceanic Crust and Continental crust is Generate heat in Subduction zone. Now water Vapor, less pressure and frictional
heating plays together to melt Asthenosphere Rock. Volcanoes and Plutonic Rocks are the Result of Subduction Zone The Pacific North west is
example of Volcano, So the Granitic Cliffs of Yosemite and Andes mountains are example of plutonic rocks
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Volcano
Extinct Volcanoes
Lithosphere
Oceanic Crust +Upper Mantle
Oceanic Crust
Magma Formation
(Partial Melting)
Rising Mantle Plume
Asthenosphere
Rising
Mantle
Plume
Figure 14 Magma of Mantle Plume
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Thank You!!