01-InTRO Physical Geology

8/6/2019 01-InTRO Physical Geology

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Chapter 1Chapter 1

Introduction to GeologyIntroduction to Geology

Dr. Adly Kh. AlDr. Adly Kh. Al--SaafinSaafin

Engg. / Env. GeologyEngg. / Env. Geology

Earth Sciences Dept.Earth Sciences Dept.

KFUPMKFUPM -- DhahranDhahran


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OBJECTIVESOBJECTIVES

DistinguishDistinguish betweenbetween physicalphysical andand historicalhistoricalgeologygeology

DescribeDescribe thethe naturenature ofof scientificscientific inquiryinquiry

DiscussDiscuss somesome geologicgeologic conceptsconcepts:: CatastrophismCatastrophism

andand UniformitarianismUniformitarianism

UnderstandingUnderstanding thethe theorytheory forfor thethe originorigin ofof thethesolarsolar systemsystem andand EarthEarth

DescribeDescribe thethe earth'searth's basicbasic internalinternal structurestructure

DescribeDescribe thethe faceface ofof thethe EarthEarth

UnderstandUnderstand thethe RockRock CycleCycle andand howhow thetheformationformation ofof variousvarious typestypes..


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1.1. Define geologyDefine geology

2.2. Geologic ConceptsGeologic Concepts

3.3. Geologic timeGeologic time

4.4. Nature of scientific inquiryNature of scientific inquiry

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

6.6. Earths internal structureEarths internal structure

7.7. The Face of EarthThe Face of Earth

8.8. Earth as a systemEarth as a system

9.9. Rocks and the Rock CycleRocks and the Rock Cycle

OUTLINEOUTLINE


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Definition: what is geologygeology?

GeologyGeology:: the science that pursuesan understanding of ourplanet 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. PhysicalPhysical geologygeology::

Examines materials Earth is made of and processes

occurring on and beneath the surface of the earth.

DealsDeals withwith thethe rockrock materialsmaterials andand geologicgeologic processesprocesses

2.2. HistoricalHistorical geologygeology::

Examines origin of the Earth, origin of life, and

changes in Earth and life through time.

DealsDeals withwith thethe layeredlayered rockrock recordrecord andand fossilsfossils


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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;; statesstates thatthat Earth'sEarth's landscapeslandscapes havehave beenbeendevelopeddeveloped primarilyprimarily byby greatgreat catastrophescatastrophes..

FeaturesFeatures suchsuch asas mountainsmountains andand canyonscanyons werewereproducedproduced byby suddensudden andand oftenoften worldwideworldwide

disastersdisasters.

UUniformitarianismniformitarianism:: oneone ofof thethe fundamentalfundamental principlesprinciples ofofmodernmodern geologygeology advancedadvanced byby JamesJames HuttonHutton inin thethe latelate

17001700ss,, statesstates thatthat: thethe physical,physical, chemical,chemical, andand biologicalbiological

operationsoperations thatthat operateoperate todaytoday havehave alsoalso operatedoperated ininthethe geologicgeologic pastpast..

TheThe ideaidea isis oftenoften summarizedsummarized asas "the"thepresentpresent isis thethe keykey toto thethe pastpast..

2.2. Geologic ConceptsGeologic Concepts


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Geologists are now able to

assign fairly accurateaccurate datesdates totoeventsevents inin EarthEarth historyhistory..

i.i.RelativeRelative datingdating

ii.ii. AbsoluteAbsolute datingdating

3.3. Geologic TimeGeologic Time3.3. Geologic TimeGeologic Time


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i.i. RelativeRelative datingdating andand thethe geologicgeologic

timetime scalescaleRelativeRelative datingdating means that dates are placed

in their proper sequence or orderorder withoutknowingknowing theirtheir ageage inin yearsyears.

How are relative ages of rocks classified?

Ages of rocks are classified into several categoriesAges of rocks are classified into several categories

based on thebased on the fossils assemblagefossils assemblage..

TheThe magnitudemagnitude ofof geologicgeologic timetime;; involves vast times millions or billions of years.


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The fossils evolutionevolution is a clock of relative time, it is

called the PrinciplePrinciple ofof faunalfaunal successionsuccession.

FossilsFossils

allows geologists

to identify rocks

of same age in

different places.

mammalsmammals

reptilesreptilesamphibiansamphibians

insectsinsects

plantsplants

fishesfishesorganisms with shellsorganisms with shells

multimulti--celled organismscelled organisms

oneone--celled organismscelled organisms

YOUNGESTYOUNGEST

OLDESTOLDEST


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TheGeologicTime Scale


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

44..55 toto 44..66 billionbillion yearsyears (4,500,000,000 to

4,600,000,000 years) determined throughradiometricradiometric datingdating (Uranium,Uranium, ThoriumThorium).


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ScienceScience assumes the naturalnatural worldworld isisconsistentconsistent andand predictablepredictable mannermanner..

GoalGoal ofof sciencescience::

understandunderstand underlyingunderlying patternspatterns inin naturenature that letsus make predictionspredictions..

ScientistsScientists collectcollect datadata throughthrough::

(i)(i) Observation,Observation, andand

(ii)(ii) MeasurementsMeasurements

NOTENOTE: There is no fixed path that scientists follow andleading to scientific knowledge..

4.4. NatureNature ofof scientificscientific inquiryinquiry4.4. NatureNature ofof scientificscientific inquiryinquiry


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Nature of scientific inquiryNature of scientific inquiry

Things happen is explained using a:

HypothesisHypothesis:: IdeasIdeas toto explainexplainobservationsobservations or (untested explanation).

TheoryTheory:: aa wellwell--testedtested hypothesishypothesis.

A Theory is widely accepted explanationby scientific community.


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Nature of scientific inquiryNature of scientific inquiry

Four basic stepsFour basic steps::

1.1. COLLECTCOLLECT THETHE FACTSFACTS: Observations &measurements

2.2. DEVELOP HYPOTHESISDEVELOP HYPOTHESIS (one or more)

3.3. TESTTEST HYPOTHESISHYPOTHESIS:: REJECT,REJECT, MODIFY,MODIFY, oror ACCEPTACCEPT

4.4. THEORYTHEORY


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Geology and ManGeology and Man

1. Urbanization programs

2. Natural resources3. Natural hazards

4. Man-made hazards

5. Global problems

Briefly outline the importance ofBriefly outline the importance ofGeology in the modern society.Geology in the modern society.


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33. Natural Resources

22. External Geologic Processes

22. Internal Geologic Processes

11. Earths Materials

Aspects of Physical GeologyAspects of Physical GeologyAspects of Physical GeologyAspects of Physical Geology

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. Earths Origin &FormationEarths Origin &Formation


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HowHow waswas EarthEarth formedformed inin space?space?

EarthEarth FormationFormation::1. Most researchers believe that EarthEarth andand thethe otherother

planetsplanets formed atat thethe samesame timetime, and

2. It is formed from samesame materialmaterial ofof thethe SunSun.

OriginOrigin ofof planetplanet EarthEarth::

NebularNebular hypothesishypothesis::

SolarSolar systemsystem formed from giantgiant cloudcloud mostly ofhydrogenhydrogen ((HH)) andand heliumhelium ((HeHe)), and a smallsmall

percentagepercentage ofof ((heavyheavy elementselements)).

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 HypothesisNebular Hypothesis

Giant Cloud Rotating Disk

Star-like Bodies

Planets


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Nebular hypothesisNebular hypothesis

FormationFormation ofof thethe solarsolar systemsystem accordingaccording toto thethenebularnebular hypothesishypothesis..

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

B. The nebula contractedcontracted into a rotatingrotating diskdiskC.C. CoolingCooling of the nebular cloud caused rockyrocky andand

metallicmetallic materialmaterial toto condensecondense intointo tinytiny solidsolidparticlesparticles.

C.C. RepeatedRepeated collisionscollisions caused the dust-size particlesto gradually gather into asteroidasteroid--sizesize (star(star--like)like)bodiesbodies.

D. Within a few million years these bodies accretedaccreted

into the planetsplanets.


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( ) Cooling of the nebula causes

condensation of dust into solidparticles.

( ) Accretion of planets.

( ) Contraction of the nebula into arotating disk.

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

Label the sequence of events describing the

nebular origin of the solar system

(A)(A) TheThe earlyearly solarsolar systemsystem isis aa dustdust

andand gasgas cloudcloud ((nebulanebula))..(B)(B) ContractionContraction ofof thethe nebulanebula intointo aa

rotatingrotating diskdisk..

(C)(C) CoolingCooling ofof thethe nebulanebula causescausescondensationcondensation ofof dustdust intointo solidsolid

particlesparticles..

(D)(D) AccretionAccretion ofof planetsplanets..


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The Solar System


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The EarthThe Earth


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6.6. The face of EarthThe face of Earth


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The face of EarthThe face of Earth

Earths surfaceEarths surface::

1.1.ContinentsContinents

2.2.OceansOceans


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1.1. ContinentsContinents::

Mountain beltsMountain belts Most prominent feature of continents

The stable interior (The stable interior (craton)

Composed ofshields and stable platforms

Earths Solid SurfaceEarths Solid Surface


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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.


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The face of Earth


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The face of EarthThe face of Earth

2.2. OceansOceans::

Continental marginContinental margin

Includes the continentalshelf, continental slope, andthe continental rise

DeepDeep--ocean basinocean basin

Abyssal plain

Oceanic trench

Seamounts Oceanic ridge systemOceanic ridge system

Most prominenttopographic feature onEarth composed of igneousigneousrockrock that has been

fractured and uplifted.


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Parts of OceanParts of OceanContinental MarginContinental Margin

Oceanic ridgeOceanic ridge

DeepDeep--ocean basinocean basin


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( ) ocean crust

( ) continental margin shoreline( ) continental shelf

( ) continental slope

( ) continental rise

( ) sediment

( ) abyssal plain

(F) ocean crust

(B) continental margin shoreline(D) continental shelf

(C) continental slope

(E) continental rise

(G) sediment

(A) abyssal plain

Choose the appropriate label for each

letter on the diagram


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7.7. Earths Internal StructureEarths Internal Structure


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Earths layered structureEarths layered structure::

1.1. CoreCore

2.2. MantleMantle

3.3. CrustCrust

7.7. Earths internal structureEarths internal structure


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Earthslayered

structure


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Earth's Internal Structure


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Earths internal structureEarths internal structure

1. crust

2. mantle

3. core

OceanicOceanic 0 - 6 km (young, < 180 m.y.)

ContinentalContinental 0 -34 km(older,upto 3.8 b.y.)

UpperUpper 34 - 670 kmLowerLower 670 - 2900 km

OuterOuter (liquid) 2900 - 5160 kmInnerInner (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 mostMantle)

2.2. AsthenosphereAsthenosphere

3.3. MesosphereMesosphere

4.4. Outer CoreOuter Core

5.5. Inner CoreInner Core

Earths internal structureEarths internal structure

MantleMantle


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Earthslayered

structure


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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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8.

8. Earth as a systemEarth as a system

8.

8. Earth as a systemEarth as a system

Types of SystemTypes of System::

Open System

Closed System

Isolated System

EarthEarth isis aa dynamicdynamic planetplanet withwithmanymany interactinginteracting partsparts (spheres)(spheres)..


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Earth System & SubsystemsEarth System & Subsystems


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Earth as a SystemEarth as a SystemEarth as a SystemEarth as a System Earth is a dynamic planet with many

interacting parts (spheres).

Earth System Science:

Earth is a system composed of numerous

interacting parts or subsystems, and

Earth system study employs an

interdisciplinary approach to solve global

environmental problems.

EarthEarth Closed SystemClosed SystemEarths SubsystemEarths Subsystem Open SystemsOpen Systems


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EarthEarth isis composedcomposed ofof fourfoursubsystemssubsystems::

1.1.HydrosphereHydrosphere

2.2. AtmosphereAtmosphere

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

4.4. BiosphereBiosphere

Earth SubsystemsEarth SubsystemsEarth SubsystemsEarth Subsystems


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TheThe EarthEarth systemsystem isis poweredpowered byby::

i.i. TheThe SunSun drives externalexternal processesprocesses atat EarthsEarths

surfacesurface: AtmosphereAtmosphere

HydrosphereHydrosphere

ii.ii. TheThe EarthsEarths interiorinterior activityactivity drives internalinternalprocessesprocesses: VolcanicVolcanic eruptionseruptions

EarthquakesEarthquakes (EQs)(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 ofEarth

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

UndergroundUnderground water,water,

GlaciersGlaciers,,

CloudsClouds

Water portion of EarthWater portion of Earth


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AtmosphereAtmosphere

Protection from Suns heat & UV

Strong interactions with surface

Blanket of air surrounding EarthBlanket of air surrounding Earth


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BiosphereBiosphere

Concentrated near Earths surface

Strong relationship with atmosphere,hydrosphere and solid earth

All life on EarthAll life on Earth


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Solid EarthSolid EarthLithosphereLithosphere


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Rock Cycle &Basic Rock TypesRock Cycle &Basic Rock Types

1.1. IgneousIgneous rocksrocks:: Cooling and solidification of magma (molten rock)

(ExamplesExamples: granite and basalt)

2.2. SedimentarySedimentary rocksrocks::

Accumulate in layers at Earths surface

Sediments are derived from weathering ofpreexisting rocks

(ExamplesExamples: sandstone and limestone).

3.3. MetamorphicMetamorphic rocksrocks:: Formed by changing preexisting igneous,

sedimentary or other metamorphic rocks

Driving forces are increased heat and pressure

(ExamplesExamples: gneiss and marble)


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RockRock CycleCycle discusses the originorigin of the

three rock types,

RockRock CycleCycle describes the looploop that involves theprocessesprocesses by which one rock changes to another,

RockRock CycleCycle illustrates the various processesprocesses

andand pathspaths as earth materials change both on thesurface and inside the Earth.

9.9.Rock CycleRock Cycle


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TheThe

RockRockCycleCycle


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Minerals & RocksMinerals & Rocks

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01-InTRO Physical Geology