Transcript Powerpoint Presentation Physical Geology, 10th ed.

GEOLOGY-1010
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INSTRUCTOR’S NAME: MARK BASKARAN
PHONE: 313-577-3262
E-MAIL: [email protected]
OFFICE HOURS: 10:30-11:30 AM-M,F
Grading Policy – GEL-1010
• LECTURE AND LAB MUST BE SUCCESFULLY COMPLETED
• FIRST QUIZ.
• GRADING
• EXAM #1=20%
• EXAM #2=20%
• FINAL =30%
• LAB =30%
COURSE GRADES WILL BE CURVED
• EXAM WILL BE MULTIPLE CHOICE AND TRUE/FALSE
• QUESTIONS
• EXAM MATERIAL FROM LECTURE NOTES, DO NOT MISS
LECTURES
• MAKE UP EXAM ………………..ONLY ON VALID EXCUSES
Lab
OPEN LAB (MAY ATTEND ANYTIME WHEN LAB IS
OPEN)
INTEGRAL AND
ESSENTIAL PART OF GEL 1010
COURSE
OF FINAL GRADE – HELPS TO IMPROVE THE
GRADE
30%
LAB WILL START IN THE
MUST
SECOND WEEK
HAVE PHOTO ID
LABORATORY OUTLINE
(BOOKSTORE OR
MARWELL’S) MUST BE BROUGHT TO THE LAB
– QUESTION QUIZ AT THE END OF EACH LAB
(COMPUTER TESTING; QUIZ WILL CONSTITUTE THE
GRADE FOR THE LAB)
20
*~ 3 HOURS – ALLOW 3.5 HOURS TO COMPLETE LAB
AND QUIZ
*NO FOOD/DRINK ALLOWED; NO VISITORS
ALLOWED
*NO LAB MAKEUPS
*LOWEST LAB WILL BE DROPPED.TOTAL 13 LABS – 1
DROP = 12 LABS
4 OR MORE LABS MISSING-MUST DROP THE COURSE
UNOFFICIAL WITHDRAWAL WILL BE GIVEN
*LAB STARTS ON TUESDAYS- ENDS THURSDAYMUST BE TAKEN THE SAME WEEK
TIPS FOR SUCCESS
READ
OUTLINE PRIOR COMING TO THE
LAB
REVIEW MATERIAL IN TEXT BOOK
RELATED TO THE LAB TOPIC
FILL IN
OUTLINE CAREFULLY AS IT
WILL BE YOUR STUDY GUIDE FOR THE
QUIZ
ASK
LAB INSTRUCTOR IF THE LAB
MATERIAL IS UNCLEAR.
Methods of Science
• DATA GATHERING
• HYPOTHESES ( LOGICAL AND TENTATIVE
EXPLANATION )
( > 50 HYPOTHESIS FOR ICE AGES )
• THEORIES ( GENERALLY ACCEPTED EXPLANATIONS)
• LAWS, SCIENTIFIC ( THEORY THAT MEETS RIGOROUS
TESTING)
• GEOLOGICAL MODELS
Scientific Theory
• MASSIVE VOLCANIC ERUPTIONS OF INDIA’S
DECCAN PLATEAU•
--------CLOUD OF V. ASH & GAS – COOLING –
DECLINE IN VEGETATION – PLANT EATING
ANIMALS WOULD HAVE DIED – MEAT EATERS
DEATH
• METEORITE IMPACT THEORY - ~ 10 KM DIAMETER
CRASHED INTO THE EARTH – DUST VEIL &
SMOKES FROM FIRE BLOCKED SUNLIGHT
Extinction of Dinosaurs
• 65 M YEARS AGO, 75% OF ALL FORMS OF LIFE VANISHED (
LAND & WATER – DWELLING)
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EPEDEMIC DISEASES ELIMINATED DINOSAUR POPULATION?
• EGG STEALING- MAMMALS RAVAGED DINOSAUR’S NESTS?
• OCEANS BECAME LETHALLY SALTY – WHY SOME MARINE
ORGANISMS SURVIVED?
• DRASTIC ENVIRONMENTAL CHANGE?
• SHIFT IN PLANET’S PROTECTIVE MAGNETIC FIELD?(
ALLOWING HARMFUL RADIATION)
EVIDENCES
• *1” – CLAYEY LAYER ~ 65 M YEAR
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CLAY CONTAINS IRIDIUM ( ABUNDANT IN METEORITE;
RARE IN INT. ROCKS)
( ABOVE THE LAYER ~ ONE FOURTH AS MANY
SPECIES)
• *PRESENCE OF TEKTITES ( GLASSY SPHERES ) IN
SEDIMENT LAYERS AROUND THE WORLD
( SUPER HEATED ROCKS AT IMPACT SITE HURLED
INTO THE AIR IN A MOLTEN STATE)
• *FOSSILS ABOVE & BELOW THIS 1”
Evidences – contd.
• *HIGH CONC. OF CARBON SOOT WITHIN THE
IRIDIUM LAYER
( EVIDENCE OF GLOBAL WILD FIRE)
*WHITISH FOSSIL – RICH LAYER AT THE
BOTTOM OF A CORE (ODP) IN ATLANTIC
OCEAN – OVERLAIN BY A THIN GRAY – GREEN
LAYER OF IMPACT DEBRIS TOPPED BY AN IRON
– RICH BAND – FOSSIL POOR LAYER ABOVE.
*IMPACT SITE – YUCATAN’S CHICXULUB
CRATER 300 KM DIAMETER.
Big Bang Theory
•TIMING ESTIMATED USING HUBBLE SPACE TELESCOPE
-CURRENT POSITIONS & SPEED OF VISIBLE GALAXIES AS THEY MOVE
FROM ONE ANOTHER
•AFTER BIG BANG, UNIVERSE BEGAN TO EXPAND & COOL
•FEW MINUTES AFTER BIG BANG, UNIVERSE COOLED BY ABOUT
•ONLY PROTONS, NEUTRONS & ELECTRONS PRESENT
• ATOMS (BUILDING BLOCKS OF MATTER)
•ONLY WHEB UNIVERSE COOLED ~ 3000 DEG CENTIGRADE,
•H, He – LIGHT ELEMENTS BEGAN TO EXIST
Big Bang Theory
Lecture Outlines
Physical Geology, 10/e
Plummer, McGeary &
Carlson
Introducing Geology
Physical Geology 10/e, Chapter 1
Plummer et al.
Geology in Today’s World
• Geology - The scientific study of the Earth
– Physical Geology is the study of Earth’s materials,
changes of the surface and interior of the Earth, and the
forces that cause those changes
• Practical Aspects of Geology
– Natural resources
– Geological hazards
– Environmental protection
Practical Aspects of Geology
• Natural Resources
– All manufactured objects
depend on Earth’s resources
– Localized concentrations of
useful geological resources
are mined or extracted
– If it can’t be grown, it must
be mined
– Most resources are limited in
quantity and non-renewable
Damage from Northridge (CA) earthquake
(1/17/1994) apartment-15 died
Resource Extraction and
Environmental Protection
• Coal Mining
– Careless mining can release acids
into groundwater
• Petroleum Resources
– Removal, transportation and waste
disposal can damage the
environment
Alaska pipeline
• Dwindling resources can encourage disregard for
ecological damage caused by extraction activities
Geologic Hazards
• Earthquakes
– Shaking can damage buildings and
break utility lines (electric, gas,
water, sewer)
• Volcanoes
– Ash flows and mudflows can
overwhelm populated areas
• Landslides, floods, and wave erosion
Geologic Hazards
• Earthquakes
– Shaking can damage buildings and
break utility lines (electric, gas,
water, sewer)
• Volcanoes
– Ash flows and mudflows can
overwhelm populated areas
• Landslides, floods, and wave erosion
Geologic Hazards
• Earthquakes
– Shaking can damage buildings and
break utility lines (electric, gas,
water, sewer)
• Volcanoes
– Ash flows and mudflows can
overwhelm populated areas
• Landslides, floods, and wave erosion
Physical Geology Concepts
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Earth’s Systems
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Atmosphere
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Hydrosphere (rivers, ocean,
glaciers, lakes)
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water on or near the Earth’s surface
Biosphere
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the gases that envelop the Earth
all living or once-living materials
Geosphere
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the solid rocky Earth
Physical Geology Concepts
• Earth’s Heat Engines
– External (energy from the Sun)
• Primary driver of atmospheric (weather) and
hydrospheric circulation
• Controls weathering of rocks at Earth’s surface
– Internal (heat moving from hot interior to
cooler exterior)
• Primary driver of most geospheric phenomena
(volcanism, magmatism, tectonism)
Earth’s Interior
• Compositional Layers
– Crust (~3-70 km thick)
• Very thin outer rocky shell of Earth
– Continental crust - thicker and less dense
– Oceanic crust - thinner and more dense
– Mantle (~2900 km thick)
• Hot solid that flows slowly over time;
Fe-, Mg-, Si-rich minerals
– Core (~3400 km radius)
• Outer core - metallic liquid;
mostly iron
• Inner core - metallic solid; mostly iron
Earth’s Interior
• Mechanical Layers
– Lithosphere (~100 km thick)
• Rigid/brittle outer shell of Earth
• Composed of both crust and
uppermost mantle
• Makes up Earth’s tectonic “plates”
– Asthenosphere
• Plastic (capable of flow) zone on
which the lithosphere “floats”
Theory of Plate Tectonics
• Continental Drift Hypothesis
(Alfred Wagner)
– Originally proposed in early 20th century to
explain the “fit of continents”, common rock
types and fossils across ocean basins, etc.
– Insufficient evidence found for driving
mechanism; hypothesis initially rejected
• Plate Tectonics Theory
– Originally proposed in the late 1960s
– Included new understanding of the seafloor
and explanation of driving force
– Describes lithosphere as being broken into
plates that are in motion
– Explains origin and locations of such things as
Tectonic Plate Boundaries
• Divergent boundaries
– Plates move apart
– Magma rises, cools and forms new lithosphere
– Typically expressed as mid-oceanic ridges
• Transform boundaries
– Plates slide past one another
– Fault zones and earthquakes mark boundary
– San Andreas fault in California
• Convergent boundaries
– Plates move toward each other
– Mountain belts and volcanoes common
– Oceanic plates may sink into mantle along a subduction
zone, typically marked by a deep ocean trench
Tectonic Plate Boundaries
• Divergent boundaries
– Plates move apart
– Magma rises, cools and forms new lithosphere
– Typically expressed as mid-oceanic ridges
• Transform boundaries
– Plates slide past one another
– Fault zones and earthquakes mark boundary
– San Andreas fault in California
• Convergent boundaries
– Plates move toward each other
– Mountain belts and volcanoes common
– Oceanic plates may sink into mantle along a subduction
zone, typically marked by a deep ocean trench
Plate Tectonics-contd.
• Top of a plate – consisting of oceanic crust, continental
crust or a part of each
• North American Plate is moving westward relative to
Europe – Plate’s divergent boundary is along midoceanic ridge in the North Atlantic Ocean
• Transform Boundary: San Andreas Fault in CA is an
example – Earthquakes along the fault are a product of
motion
• Convergent Plate Boundary: Less dense, more buoyant
continental plate will override the denser, oceanic plate
Geologic Time
• “Deep” Time
– Most geologic processes occur gradually over millions of years
– Changes typically imperceptible over the span of a human lifetime
– Current best estimate for age of Earth is ~4.55 billion years
• Geologic Time and the History of Life
– Complex life forms became abundant ~544 million years ago
– Reptiles became abundant ~230 million years ago
– Dinosaurs became extinct (along with many other organisms)
~65 million years ago
– Humans have been around for only ~ 3 million years
• “Nothing hurries geology”
Mark Twain
A Map of Tectonic Plates
A Map of the Pacific Ocean
Plate Rifting and Divergence
Divergent Zones
Oceanic Plate Subduction
Key Points
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Physical Geology
Earth’s internal and external heat engines – driving factors
Divisions of Earth’s layers
Plate Tectonics – convergent, divergent, transform boundaries
Crust – classification
Age of the Earth and Universe
Factors causing earthquakes
Lithosphere
Asthenosphere