Welcome to GeologyGEO B10

Welcome to GeologyGEO B10

Instructor Jack Pierce

Room DST 118

Instructor Jack Pierce

Room DST 118

6:00 – 9:10 pm - Tuesday6:00 – 9:10 pm - Tuesday

Tuesday, Aug 23, 2011

• Attendance• Geology Introduction

Tuesday, Aug 23, 2011

• Attendance• Geology Introduction

SILENCE YOUR CELL PHONESILENCE YOUR CELL PHONE

What is Geology?

Geo ( ) + logy ( )

Study of the Earth

More specifically: materials that compose the earth

minerals / rocks processes that shape the earth

volcanoesriversglaciersearthquakes

What is Geology?

Geo ( ) + logy ( )

Study of the Earth

More specifically: materials that compose the earth

minerals / rocks processes that shape the earth

volcanoesriversglaciersearthquakes

EARTH STUDY or SCIENCE

Geology is divided into two broad subject areas:Geology is divided into two broad subject areas:

Physical Geology / Historical GeologyPhysical Geology / Historical Geology

Physical Geology:• understanding the processes on earth below and above the earth surface and the materials (rocks) involved with these processes

Physical Geology:• understanding the processes on earth below and above the earth surface and the materials (rocks) involved with these processes

erosional processes occurring above the surfaceerosional processes occurring above the surface

earthquakes occurring below the surface transferring energy to the surface

earthquakes occurring below the surface transferring energy to the surface

processes below the earth’ssurface that move rigid platematerial on the surface

processes below the earth’ssurface that move rigid platematerial on the surface

Historical Geology• understanding the evolution of the earth and its life forms from its origins to the present day

• involves investigations into stratigraphy (rock layers), and paleontology (the fossil record)

Historical Geology• understanding the evolution of the earth and its life forms from its origins to the present day

• involves investigations into stratigraphy (rock layers), and paleontology (the fossil record)

layers of rock deposited one layerover another– preserving evidenceto the origin of the earth“The rock record”

layers of rock deposited one layerover another– preserving evidenceto the origin of the earth“The rock record”

fossils- preserved animal/plant remains in the earth’s crust demonstrating the progression of lifethroughout earth’s history

fossils- preserved animal/plant remains in the earth’s crust demonstrating the progression of lifethroughout earth’s history

The Geologic Time Scale

• attempts to organize 4.6 b.y. of the earth history

• created from both relative and absolute dating processes

• based on fossil succession and relative dating principles.

The Geologic Time Scale

• attempts to organize 4.6 b.y. of the earth history

• created from both relative and absolute dating processes

• based on fossil succession and relative dating principles.

Age ofReptiles

Amphibians

Age of fish

Invertebrates

When does the presenceof man appear on thegeologic time scale?

When does the presenceof man appear on thegeologic time scale?

Humans and Our EarthHumans and Our Earth

How long have humans inhabited the earth?How long have humans inhabited the earth?

JanJan JanJanAge of

dinosaursAge of

dinosaurs

4.6 billion years4.6 billion years

Man began inhabiting the earth (2 million years ago) --December 31, the last 30 seconds of the year!!!!

Man began inhabiting the earth (2 million years ago) --December 31, the last 30 seconds of the year!!!!

How has man impacted earth in the last 5000years (the beginning of reasonably modern times)How has man impacted earth in the last 5000years (the beginning of reasonably modern times)

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Specifically, geology is defined as:Specifically, geology is defined as:

the study of the planet earth--- materials of which it is made,the internal/external processes that act on these materials

which produce new materials (rock types) and the history of the planet and its life forms since its origin

the study of the planet earth--- materials of which it is made,the internal/external processes that act on these materials

which produce new materials (rock types) and the history of the planet and its life forms since its origin

Specific disciplines within the field of geology• Seismology

• investigate the occurrence of earthquakes

• Economic geology • formation/occurrence of mineral resources

• Volcanology • investigates volcanoes and volcanic eruptions

• Hydrogeology • investigation of surface/subsurface water processes

Specific disciplines within the field of geology• Seismology

• investigate the occurrence of earthquakes

• Economic geology • formation/occurrence of mineral resources

• Volcanology • investigates volcanoes and volcanic eruptions

• Hydrogeology • investigation of surface/subsurface water processes

Career Opportunities in the Geosciences

• Employment growth of 22% expected between 2006 and 2016. Growth is much faster than the average for all occupations.

• Average salary for geologists with BS, MS degress = 85K • More MS students are employed.• Fewer BS students are employed.

Opportunities are cyclic and dependenton the demand of commodities.

• Hot Geology Fields• petroleum industry• environmental geology• Engineering

Bottom line: Choose the geosciences because you love it!

I I geology class geology class

I will get an A on my exams and quizzes

1.What is the specific definition of geology?

2. Describe the differences between physical and historical geology.

Discuss with a friend:

How does the view of Earth influence the way we study earth??

What do you see?

Various “systems” within the earth that interactwith one another -– called Earth System Science

• Systems are NOT individually studied

• How one system impacts another system

Various “systems” within the earth that interactwith one another -– called Earth System Science

• Systems are NOT individually studied

• How one system impacts another system

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Earth as a System:• How systems exchange matter and energy

Earth as a System:• How systems exchange matter and energy

SUN

IsolatedSystemIsolatedSystem

No exchange ofmatter or energyNo exchange ofmatter or energy

SUN

ClosedSystemClosedSystem

Exchange of energybut not matterExchange of energybut not matter

SUN

OpenSystemOpen

System

Exchange of bothmatter and energyExchange of bothmatter and energy

Which system is the Earth?Which system is the Earth?

12

The Fragile Earth – A CLOSED system: The Fragile Earth – A CLOSED system:

“There is no away to throw things to.”“There is no away to throw things to.” X

xx

• Any change in a closed system will affect other systems.• Any change in a closed system will affect other systems.

• The amount of matter on earth is “fixed” – “We ain’t got no more” --- This is all we have.• The amount of matter on earth is “fixed” – “We ain’t got no more” --- This is all we have.

• When we dispose of waste, it’s still here. The waste will remain within the closed boundaries of earth.• When we dispose of waste, it’s still here. The waste will remain within the closed boundaries of earth.

13

I I this geology class. this geology class.

I will get an A on my exams and quizzes.

Discuss with a friend:

1.Define a system as discussed in earth science.

2. Differentiate between an open, closed, and isolated system.

3. Explain why earth is considered a closed system.

14

The fragile earth as a closed system is supported by fourinterrelated open systems.The fragile earth as a closed system is supported by fourinterrelated open systems.

LithosphereRepresents the solid earth:minerals, rocks, and interior

LithosphereRepresents the solid earth:minerals, rocks, and interior

Atmosphere:Thin blanket of gas keepinglife alive, warm, and protected

Atmosphere:Thin blanket of gas keepinglife alive, warm, and protected

Hydrosphere:Interaction of all water processes,only planet with water,71% ocean 12,500 feet deep,streams, lakes, groundwater

Hydrosphere:Interaction of all water processes,only planet with water,71% ocean 12,500 feet deep,streams, lakes, groundwater

Biosphere:Includes all living organisms on land, in water, and in air

Biosphere:Includes all living organisms on land, in water, and in air

GeosphereInteraction of all open systems

GeosphereInteraction of all open systems

15

Cycles and Interactions Explored in Geology

There are three (3) main earth cycles and within each cycle, multiple open systems exist.

Cycles and Interactions Explored in Geology

There are three (3) main earth cycles and within each cycle, multiple open systems exist.

Hydrologic Cycledescribes the movement of water through reservoirs of the earth system(rivers, water vapor, groundwater)

Hydrologic Cycledescribes the movement of water through reservoirs of the earth system(rivers, water vapor, groundwater)

The Rock Cycleinternal/external earth processesthat produce new rock, modifiesrock, transport rock, and breaks rocks down

The Rock Cycleinternal/external earth processesthat produce new rock, modifiesrock, transport rock, and breaks rocks downThe Tectonic Cyclemovement and interaction betweenrigid lithospheric plates, internalearth processes producing divergent,convergent, and sliding plate motions

The Tectonic Cyclemovement and interaction betweenrigid lithospheric plates, internalearth processes producing divergent,convergent, and sliding plate motions

I I geology classgeology classI I geology classgeology class

I will get an A on my exams and quizzes

1. Define the four major open systems and give an example of how systems may interact with one another.

2. Define the three major cycles used to explore geologic processes and give an example of how these cycles may interact with one another.

8.

SUN

MercuryMercury

VenusVenus

EarthEarthMarsMars

JupiterJupiter SaturnSaturn

UranusUranusNeptuneNeptune

Asteroid BeltAsteroid Belt

Outer planetsJovian planetsGas planets

Outer planetsJovian planetsGas planets

Inner planetsTerrestrial planets

Inner planetsTerrestrial planets

The earth’s place in the solar systemThe earth’s place in the solar system

Low densitiesLow densities

High densitiesHigh densities 28

The earth’s interior

Inner CoreSolid- Ni, Fe12.5 g/cm3

Outer CoreMolten – Ni,

Fe11.5 g/cm3

Mantle -Solid

Si,O,Fe,Mg,Ca

5.5 g/cm3

Temp:5000 C

Source ofmagnetic

field

Asthenosphereductile rock

Mantle

Core

LithosphereCont/ocean

crustUpper mantle

2.8 g/cm3

Crust

Why are densitiesarranged from

heavy (core) to lightest (crust)?

Chemical Differentiation

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What makesearth unique?? Oxygen, water, life

• oxygen atmosphere• no O2 on other planets• the hydrologic cycle

Soil accumulation• weathering of rocks• various soil types

Plate Tectonics• moving continents• formation of landforms from interacting plates

Oxygen, water, life• oxygen atmosphere• no O2 on other planets• the hydrologic cycle

Soil accumulation• weathering of rocks• various soil types

Plate Tectonics• moving continents• formation of landforms from interacting plates

30

Plate Tectonics• The movement and interactions of large fragments of earth lithosphere (called plates)

• earthquakes• new landforms• volcanoes• new climatic regions on the earth• creation of new rock types on the crust

Plate Tectonics• The movement and interactions of large fragments of earth lithosphere (called plates)

• earthquakes• new landforms• volcanoes• new climatic regions on the earth• creation of new rock types on the crust

Oceanic Crust• Thin, dense (Fe, Mg) young rock –basalt underlying the ocean floor

Oceanic Crust• Thin, dense (Fe, Mg) young rock –basalt underlying the ocean floor

Continental Crust• Thicker, less dense (Si,O) older rock – granite making the bulk of the earth’s land

Continental Crust• Thicker, less dense (Si,O) older rock – granite making the bulk of the earth’s land 31

Plate Tectonics!!!Plate Tectonics!!!

Scientists use fossil evidence,sea floor evidence, and climaticevidence to reconstruct the continents!!!!!!– HOT TOPIC

Scientists use fossil evidence,sea floor evidence, and climaticevidence to reconstruct the continents!!!!!!– HOT TOPIC

32

I I Earth Science. Earth Science.

I will get an A on my exams and quizzes.

Discuss with a friend:1.Name the planets in their proper order.

2. Describe the layering of the earth using lithosphere, asthenosphere, mantle, and core; explain properties.

3. Describe chemical differentiation.

4. Present at least 3 reasons why the earth is unique.

33

• Is the Earth old or considered young?

• Are earth process rates rapid or slow?

• How can rock (considered 2-b.y. old) have the same composition of present rock produced today?

• If mountains are built through tectonic processes, why can’t we make obvious observations?

• In terms of geologic time, why is it possible for a storm to erode 2-million years of rock formation in a single day?

• Is the Earth old or considered young?

• Are earth process rates rapid or slow?

• How can rock (considered 2-b.y. old) have the same composition of present rock produced today?

• If mountains are built through tectonic processes, why can’t we make obvious observations?

• In terms of geologic time, why is it possible for a storm to erode 2-million years of rock formation in a single day?

Geo-philosophical Questions

Historical aspects about geology

There are two schools of thought on the geologic history and processes that formed our earth.

Historical aspects about geology

There are two schools of thought on the geologic history and processes that formed our earth.

Catastrophism vs. UniformitarianismCatastrophism vs. Uniformitarianism

4

Catastrophism: (mid-1600’s)powerful geologic events that shape the earth in a single incident

Volcanic eruptions

EarthquakesMassive floodsLandsliding

Catastrophism: (mid-1600’s)powerful geologic events that shape the earth in a single incident

Volcanic eruptions

EarthquakesMassive floodsLandsliding

5

Catastrophism: (mid-1600’s) published by Anglican Archbishop, James Ussher

determined that earth was only a few thousand years old – created in 4004 BC

suggested that earth landscapes are fashioned by great catastrophes – features form rapidly

an attempt to fit the formation of earth features into a short amount of time (6000 years – Biblical philosophy- creationist viewpoint)

Catastrophism: (mid-1600’s) published by Anglican Archbishop, James Ussher

determined that earth was only a few thousand years old – created in 4004 BC

suggested that earth landscapes are fashioned by great catastrophes – features form rapidly

an attempt to fit the formation of earth features into a short amount of time (6000 years – Biblical philosophy- creationist viewpoint) 6

Uniformitarianism – Birth of Modern Geology

• “The present is the key to the past.”

Uniformitarianism – Birth of Modern Geology

• “The present is the key to the past.”

Uniformitarianism states:

Physical, chemical, and biological laws that operate today have also operated in the

geologic past.

Uniformitarianism states:

Physical, chemical, and biological laws that operate today have also operated in the

geologic past.

Proposed by James Hutton – late 1700’s• argued using the “rock cycle” concept• argued using earth processes that can be observed

• What is required? TIME

Proposed by James Hutton – late 1700’s• argued using the “rock cycle” concept• argued using earth processes that can be observed

• What is required? TIME7

The Uniformitarianism philosophyDo geologic processes act slowly or rapidly?How many catastrophic events take place/day?

When was the last major volcanic eruption?

When was the last major earthquake?How long does it take a river to carve a

canyon?How fast are the continents moving?

Do you consider yourself a catastrophist or a uniformitarianist?

The Uniformitarianism philosophyDo geologic processes act slowly or rapidly?How many catastrophic events take place/day?

When was the last major volcanic eruption?

When was the last major earthquake?How long does it take a river to carve a

canyon?How fast are the continents moving?

Do you consider yourself a catastrophist or a uniformitarianist? 8

Taking Uniformitarianism literally – Problem with “U”Rates and intensities of geologic processes change over time.

Example:10,000 years ago, large land masses were covered in ice.

Different type of geologic environment than today

Different intensityDifferent rates of erosion

Given the concept of Uniformitarianism, would you consider the earth to be very OLD or very YOUNG?

Taking Uniformitarianism literally – Problem with “U”Rates and intensities of geologic processes change over time.

Example:10,000 years ago, large land masses were covered in ice.

Different type of geologic environment than today

Different intensityDifferent rates of erosion

Given the concept of Uniformitarianism, would you consider the earth to be very OLD or very YOUNG? 9

I I geology class. geology class.

I will get an A on my exams and quizzes.

Discuss with a friend:

1.Describe the differences between catastrophism and uniformitarianism.

2. Provide at least 2 examples each of catastrophism and uniformitarianism.

3. Identify “problems” with both philosophies.

10

Why do we care and study our earth (geology)?Why do we care and study our earth (geology)?

Earth resources:• societies depend on minerals and rocks for material

resources• soils that produce agriculture products • the availability of fresh water for everyone

Earth resources:• societies depend on minerals and rocks for material

resources• soils that produce agriculture products • the availability of fresh water for everyone

Geologic hazards:• volcanic eruptions, landslides, earthquakes, floods

(when does nature become a geologic hazard?)

Geologic hazards:• volcanic eruptions, landslides, earthquakes, floods

(when does nature become a geologic hazard?)

The uniqueness of earth• constant fascination and can give one geologic chills• earth processes may open the door for other planetary

processes

The uniqueness of earth• constant fascination and can give one geologic chills• earth processes may open the door for other planetary

processes

Students need the science requirement for their degree!

Students need the science requirement for their degree!