Chapter 1Chapter 1

Introduction to GeologyIntroduction to Geology

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OBJECTIVESOBJECTIVES Distinguish between physical and historical Distinguish between physical and historical

geologygeology

Discuss some geologic concepts: Discuss some geologic concepts: CatastrophismCatastrophism and and UniformitarianismUniformitarianism

Understanding the theory for the Understanding the theory for the origin of the origin of the solar system and Earthsolar system and Earth

Describe the earth's basic Describe the earth's basic internal structureinternal structure

Describe the Describe the face of the Earthface of the Earth

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1.1. Define geologyDefine geology

2.2. Geologic ConceptsGeologic Concepts

3.3. Geologic timeGeologic time

4.4. Origin of Earth & Solar SystemOrigin of Earth & Solar System

5.5. Earth’s internal structureEarth’s internal structure

6.6. The Face of EarthThe Face of Earth

7.7. Earth as a systemEarth as a system

OUTLINEOUTLINE

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Definition: what is geologygeology?

GeologyGeology: : the science that pursues an understanding of our planet “The Earth”.

1.1. Define GeologyDefine Geology

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Components of GeologyComponents of Geology

GeologyGeology is divided into two broad areas:1.1. Physical geologyPhysical geology::

Examines materials Earth is made of and processes occurring on and beneath the surface of the earth.

Deals with theDeals with the rock materialsrock materials and and geologic processesgeologic processes

2.2. Historical geologyHistorical geology::Examines origin of the Earth, origin of life, and

changes in Earth and life through time.

Deals with theDeals with the layered rock record and fossilslayered rock record and fossils

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Physical GeologyPhysical Geology

Physical GeologyPhysical Geology Deals With:Deals With:1.1. Earth materialsEarth materials::

atoms, minerals, rocks, salt, gems, sand, gravel, clay, soil, atmosphere, hydrosphere, organisms, building materials, coal, oil, gas, water, soil, salt, jewelry, etc.

2.2. Earth (Geologic) processesEarth (Geologic) processes: earthquakes, volcanic eruptions, floods,

continental drift, weathering, landslides, subsidence and collapse, tides, geysers, erosion, etc.

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CCatastrophismatastrophism; ; states that Earth's landscapes have been states that Earth's landscapes have been developed primarily by great developed primarily by great catastrophescatastrophes..

Features such as mountains and canyons were Features such as mountains and canyons were produced by sudden and often produced by sudden and often worldwide worldwide disastersdisasters.

UUniformitarianismniformitarianism:: one of the fundamental principles of one of the fundamental principles of modern geology advanced bymodern geology advanced by James HuttonJames Hutton in the late 1700in the late 1700ss, , states thatstates that: the physical, chemical, and biological the physical, chemical, and biological

operations that operateoperations that operate todaytoday have also operated in have also operated in

thethe geologic pastgeologic past..

The idea is often summarized asThe idea is often summarized as "the "the present is the key to the past“. present is the key to the past“.

2.2. Geologic ConceptsGeologic Concepts

Mountains.flv

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Geologists are now able to assign fairly accurate datesaccurate dates to to events in Earth history.events in Earth history.

i.i.Relative dating Relative dating

ii.ii. Absolute datingAbsolute dating

3.3. Geologic TimeGeologic Time3.3. Geologic TimeGeologic Time

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The fossils evolutionevolution is a clock of relative time, it is called the Principle of faunal successionPrinciple of faunal succession.

FossilsFossils

allows geologists to identify rocks of same age in different places.

mammalsmammals

reptilesreptiles

amphibiansamphibians

insectsinsects

plantsplants

fishesfishes

organisms with shellsorganisms with shells

multi-celled organismsmulti-celled organisms

one-celled organismsone-celled organisms

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TheGeologic

Time Scale

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How old is the Earth?How old is the Earth?

4.5 to 4.6 billion years4.5 to 4.6 billion years (4,500,000,000 to 4,600,000,000 years) determined through radiometric datingradiometric dating (Uranium, ThoriumUranium, Thorium).

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33. Natural Resources

22. External Geologic Processes

22. Internal Geologic Processes

11. Earth’s Materials

Aspects of Physical GeologyAspects of Physical GeologyAspects of Physical GeologyAspects of Physical GeologyD

EFIN

E

GEO

LO

GY

DEFIN

E

GEO

LO

GY Mineral & energy resources, economic / environmental

issues

Water, minerals, oil and gas

Effect of water, rivers, wind, and ice on landscapes

Earthquakes, magnetism, heat flow, plate tectonics

NOTICENOTICE

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5.5. Earth’s Origin & FormationEarth’s Origin & Formation

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How was Earth formed in space?How was Earth formed in space?Earth FormationEarth Formation::

1. Most researchers believe that Earth and the other Earth and the other planetsplanets formed at the same timeat the same time, and

2. It is formed from same material of the Sunsame material of the Sun.

Origin of planet Earth:Origin of planet Earth:

Nebular hypothesisNebular hypothesis::Solar systemSolar system formed from giant cloudgiant cloud mostly of hydrogen (hydrogen (HH) and helium () and helium (HeHe)), and a small small percentage of (percentage of (heavy elementsheavy elements)).

5.5. Early evolution of EarthEarly evolution of Earth5.5. Early evolution of EarthEarly evolution of Earth

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Origin of the Solar SystemOrigin of the Solar System

Nebular Hypothesis

Giant Cloud Rotating Disk

Star-like Bodies

Planets

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Nebular hypothesisNebular hypothesisFormation of the solar system according to the Formation of the solar system according to the nebular hypothesis.nebular hypothesis.

A. The birth of our solar system began as dust and gases (nebulanebula)

B. The nebula contractedcontracted into a rotating diskrotating disk

C.C. CoolingCooling of the nebular cloud caused rocky and rocky and metallic material to condense into tiny metallic material to condense into tiny solid solid particlesparticles.

C.C. Repeated collisionsRepeated collisions caused the dust-size particles to gradually gather into asteroid-size (star-like) asteroid-size (star-like) bodiesbodies.

D. Within a few million years these bodies accretedaccreted into the planetsplanets. 1-8-2011 KSGI Dept of civil engg

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( ) Cooling of the nebula causes condensation of dust into solid particles.

( ) Accretion of planets.

( ) Contraction of the nebula into a rotating disk.

( ) The early solar system is a dust and gas cloud (nebula).

Label the sequence of events describing the nebular origin of the solar system

(A)(A) The early solar system is a dust The early solar system is a dust and gas cloud (and gas cloud (nebulanebula).).

(B)(B) Contraction of the nebula into a Contraction of the nebula into a rotating disk. rotating disk.

(C)(C) Cooling of the nebula causes Cooling of the nebula causes condensation of dust into solid condensation of dust into solid particles. particles.

(D)(D) Accretion of planets. Accretion of planets.

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6.6. The face of EarthThe face of Earth

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The face of EarthThe face of Earth

Earth’s surfaceEarth’s surface::

1.1.ContinentsContinents

2.2.OceansOceans

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EARTH'S MOUNTAINEARTH'S MOUNTAIN

This map shows the general distribution of Earth's rocks: (1) shields, (2) stable platforms, and (3) mountain belts. 1-8-2011 KSGI Dept of civil engg

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Earth’s layered structureEarth’s layered structure::

1.1. CoreCore2.2. MantleMantle3.3. CrustCrust

7.7. Earth’s internal structureEarth’s internal structure

Layers of the Earth (for science class).mp4

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Earth’slayered

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Earth’s internal structureEarth’s internal structure

1. crust

2. mantle

3. core

OceanicOceanic 0 - 6 km (young, < 180 m.y.)ContinentalContinental 0 -34 km (older, up to 3.8 b.y.)

UpperUpper 34 - 670 kmLowerLower 670 - 2900 km

OuterOuter (liquid) 2900 - 5160 kmInner Inner (solid) 5160 - 6370 km

i.i. Layers defined by compositionLayers defined by composition::

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ii.Layers defined by physical properties

1.1. LithosphereLithosphere (Crust + upper most Mantle)

2.2. AsthenosphereAsthenosphere

3.3. MesosphereMesosphere

4.4. Outer CoreOuter Core

5.5. Inner CoreInner Core

Earth’s internal structureEarth’s internal structure

MantleMantle

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( ) oceanic crust ( ) mantle ( ) lithosphere

( ) inner core ( ) mesosphere ( ) continental crust

( ) asthenosphere ( ) outer core

(H) oceanic crust (G) mantle (E) lithosphere

(A) inner core (C) mesosphere (F) continental crust

(D) asthenosphere (B) outer core

Label the diagram with the appropriate termsLabel the diagram with the appropriate terms

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8.8. Earth SystemEarth System

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Earth is composed of four Earth is composed of four subsystemssubsystems::

1.1. HydrosphereHydrosphere

2.2. AtmosphereAtmosphere

3.3. Lithosphere (Solid Earth)Lithosphere (Solid Earth)

4.4. BiosphereBiosphere

Earth SubsystemsEarth Subsystems Earth SubsystemsEarth Subsystems

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The Earth system is powered byThe Earth system is powered by::i.i. The SunThe Sun drives external processesexternal processes at Earth’s at Earth’s

surfacesurface: AtmosphereAtmosphere HydrosphereHydrosphere

ii.ii. The Earth’s interior activityThe Earth’s interior activity drives internal internal processesprocesses:

Volcanic eruptionsVolcanic eruptions Earthquakes (EQs)Earthquakes (EQs)

Earth as a SystemEarth as a SystemEarth as a SystemEarth as a System

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HydrosphereHydrosphere

OceansOceans (most prominent): 71% of surface of Earth

Surface water (streams, lakes,…) Surface water (streams, lakes,…)

Underground water, Underground water,

GlaciersGlaciers, ,

CloudsClouds

Water portion of EarthWater portion of Earth

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AtmosphereAtmosphere

Protection from Sun’s heat & UV

Strong interactions with surface

Blanket of air surrounding EarthBlanket of air surrounding Earth

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BiosphereBiosphere

Concentrated near Earth’s surface

Strong relationship with atmosphere, hydrosphere and solid earth

All life on EarthAll life on Earth

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Solid EarthSolid Earth ““LithosphereLithosphere””

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top 10 natural disasters.flv

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Geology and ManGeology and Man

1. Urbanization programs 2. Natural resources 3. Natural hazards 4. Man-made hazards 5. Global problems

Briefly outline the importance of Briefly outline the importance of Geology in the modern society.Geology in the modern society.

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GEOLOGY FOR CIVIL ENGINEERS

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