what is physical geology?
TRANSCRIPT
Earth SC-202 Physical Geology
Instructor
• Prof. Steven Dutch• Office: LS 402• Phone: 465-2246• Email: [email protected]• Home Page: www.uwgb.edu/dutchs• Office Hours MWF 10:30-11:30, TR 9:30-10:50
Rocks
Igneous
Sedimentary
MetamorphicVolcanoes
Intrusions
Weathering
SoilsErosion
WaterUnderground Surface
Oceans
Wind
Glaciers
Fossils
Earth History
Earth’s InteriorEarthquakes
Mountains
Plate Tectonics
Other Planets
Mineral Resources
What is Physical Geology?
Syllabus• Introduction to the course• Minerals• Igneous Rocks and
Volcanoes • Weathering and Erosion • Evolution of Landscapes• Sedimentary Rocks• Evolution, Fossils, Geologic
Time• Glaciers • Wind and Wave Erosion
• Metamorphism and Deformation
• Earthquakes and Earth's Interior
• Continental Drift and Plate Tectonics
• Resources from the Earth • Geology of other Worlds
Exams and GradingMidterm I 50 pointsMidterm II 50 pointsLab 100 pointsFinal 80 pointsField Trip 20 pointsAttendance 10 points
Total 300 points
A 270+AB 255-269B 240-254BC 225-239C 210-224CD 205-210D 200-204
Field Trip
• Dates• Mandatory – Absence Excuse Required• 8:00 LS Parking Lot, Return 4:15• Casual Clothing – No strenuous hiking• Bring a lunch and fluids• Rest stops provided• Put on your calendar! No excuses!
Lab• Instructor:
Jennifer Wessel• Enroll in one
section• 100 points total
Expectations
• Commitment– Focus in class
• Professional Conduct– No talking, texting– Stay whole period– Stay vertical and awake
• Use Syllabus• Know your ID number or bring ID to exams
Sample exam question
• Which is the most desirable property in a gemstone?a. High hardnessb. Low hardnessc. Excellent cleavaged. Density
Signs of Trouble• Not making connections– Lecture, lab, text, on-line, exams
• Not knowing your grade• Not knowing what to study for• Not knowing what’s on syllabus
Geology and Other SciencesPhysics
•Geophysics
•Seismology
Chemistry
•Mineralogy
•Petrology
•Geochemistry
Biology
•Paleontology
•Paleo????ology
Astronomy
•Planetary Geology
•Helioseismology
Geology
•Economic Geology
•Hydrology
•Engineering Geology
•Historical Geology
•Geomorphology
•Oceanography
•Structural Geology
•Volcanology
Who Geoscientists Are:
• About 30,000 in the U.S. • Globally, in rich and poor countries, about one
per $50 million GNP. • Mostly male but changing rapidly (now about
25% female in U.S.) • Still less than 10% minority in U.S. (moving up
slowly)
Where Geologists Work
• 40 % Private Sector • 30 % Academic • 30 % Government
What Geologists Do: • Locate Geologic Resources• Geologic Hazard Mitigation– Geological and Mining Engineering – Site Study – Land-Use Planning
• Environmental Protection– Environmental Impact – Ground Water and Waste Management
• Basic Research (Furnishes fundamental knowledge for the applications)
Some Unique Aspects of GeologyImportance of Relationships• Sequential • Spatial Importance of TimeDistinctive Problems of Evidence• Slow Rates • Rare Events • Destruction of Evidence • Inaccessibility
Some Geologic RatesCutting of Grand Canyon• 2 km/3 m.y. = 1 cm/15 yrUplift of Alps• 5 km/10 m.y. = 1 cm/20 yr.Opening of Atlantic• 5000 km/180 m.y. = 2.8 cm/yr.Uplift of White Mtns. (N.H.) Granites• 8 km/150 m.y. = 1 cm/190 yr.
Some Geologic RatesMovement of San Andreas Fault• 5 cm/yr = 7 m/140 yr.Growth of Mt. St. Helens• 3 km/30,000 yr = 10 cm/yr.Deposition of Niagara Dolomite• 100 m/ 1 m.y.? = 1 cm/100 yr.
1 Second = 1 Year• 35 minutes to birth of Christ• 1 hour+ to pyramids• 3 hours to retreat of glaciers from Wisconsin• 12 days = 1 million years• 2 years to extinction of dinosaurs• 14 years to age of Niagara Escarpment• 31 years = 1 billion years
Some Unique Aspects of Geology (Continued)
Reliance on Inference and DeductionIntrinsically "Unsolvable" Problems• Ancient Landscapes • Mass Extinctions • Ancient Ocean Basins
Scientific Principles in Geology
• Parsimony (K.I.S.S.)• Superposition• Uniformitarianism
Using these, plus observation, we establish facts about Earth Processes
Parsimony
• The simplest explanation that fits all the data is preferred
• Doesn’t guarantee that things must be simple!• Theories with lots of ad hoc or unsupported
ideas are probably wrong.
Parsimony: What is the best interpretation of this well data?
Parsimony
• This?
• Or This?
Parsimony
• Rock layers throughout NE Wisconsin are nearly flat and little disturbed
• Glacial deposits are always on top of bedrock
• Therefore this is the most likely interpretation
One Implication of ParsimonyHow do we know the laws of nature are the same
everywhere?• Out to the farthest stars, everything seems to
obey the same laws of nature• We find nothing in the rocks to suggest the laws
of nature were different in the pastEither:• The laws of nature change but just happen to
produce effects that look like the presently-known laws of nature – or –
• The laws of nature really are the same everywhere
Another Implication of Parsimony
• We live in a universe of patterns• If someone claims there is an
exception to a known pattern, the simplest explanation is that he/she is wrong
• Therefore the burden of proof in science is on the challenger
Superposition
Whodunit?• Last night, one of Green Bay’s premier beer
can collections was stolen• The only clue is footprints in the snow• The thief was the last person to leave the
premises
The Suspects
• The Nephew Has a seeing-eye dog • The Maid Drives a car• The Cook Rides a motorcycle • The Handyman Rides a bike• The Butler Walks to work
The Crime Scene• The
Nephew has a seeing-eye dog
• The Maid Drives a car
• The Cook Rides a motorcycle
• The Handyman Rides a bike
• The Butler Walks to work
Contacts
A Contact:Mindoro Cut,
Wisconsin
Uniformitarianism
Continuity of Cause and Effect• Apply Cause and Effect to Future - Prediction • Apply Cause and Effect to Present -
Technology • Apply Cause and Effect to Past -
Uniformitarianism
Uniformitarianism does not mean:
• Catastrophes never occur • Physical Conditions on Earth never Change • Earth has always been the same • Physical processes always occur at the
same rate or intensity • Laws of Physics have always been the same
Uniformitarianism does mean:
Using our knowledge of physical laws, we can test:• Whether catastrophes have occurred • Whether physical conditions on earth have changed,
and if so, how (ice ages, warm periods, high or low sea level, etc.)
• Whether physical laws themselves have changed in time, or elsewhere in the universe.