Geology 101 - Physical Geology
Dr. Arlo Weil
Geology 101 - Physical Geology
Dr. Arlo Weil
What is Geology?
Webster’s Definition:
Main Entry: ge·ol·o·gy
Pronunciation: jE-'ä-l&-jE
Function: noun
Inflected Form(s): plural -gies
Etymology: New Latin geologia,
from ge- + -logia -logy
Date: 1735
1 a : a science that deals with the
history of the earth and its life
especially as recorded in rocks b : a
study of the solid matter of a
celestial body (as the moon)
Sumatra Tsunami
Sumatra Tsunami
Major Geologic Features of the Earth
Earth’s Outermost
layers
• Atmosphere
• Hydrosphere
• Biosphere
Earth’s Surface
• Continental
• Oceanic
Earth’s Interior
Structure
• Chemical
• Physical
Geology 101 - Physical Geology
Research Interests
•Formation of Mountain Belts
•Formation and Dispersal of Supercontinents
•Paleomagnetism
Class Objective: At the end of our 15-week meeting, I hope that all class
participants will have a fundamental understanding of how the Earth works.
Topics will include, but are not limited to, an understanding of geologic time,
how our planet came to be, the physical processes that are, and were, active
in forming our planet, the influences we have on the well-being of our planet,
and lastly what as scientists and "earthlings" do we still not fully understand
about our planet.
Ultimately, I hope that this class inspires you to become keen observers
of the planet on which you live, as well as provide you with the intellectual
foundation to be able to think about and answer many diverse questions
concerning our planet.
Class Syllabus
Homework Assignments
Course Outline
Course News
Lecture Notes
Geology in the News
Lab Page
Cool Geology Links
Return to Geology Department Page
Return to Bryn Mawr College Homepage
E-Mail Arlo
Course Syllabus
Required reading: Essentials of Geology, by Stephen Marshak
Grading:
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•
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Two one-hour midterm exams
One one-hour final exam
Homework exercises
Lab assignments
One topical geology review paper and poster
20%
10%
10%
50%
10%
Total 100%
Introductions
Name:
ID #:
Year:
Point of Origin:
3 locations on Earth of Geologic Interest to YOU:
Why Geology:
Cosmology
Geocentric Universe Concept
Retrograde Planetary Motion
Retrograde Planetary Motion
The Ptolemy Model (100-170 C.E.)
Heliocentric Universe Concept ~250 B.C.
Copernicus and Galileo ~ 1500s
Retrograde Planetary Motion
The Copernicus Model (~1500 C.E.)
Parallax
Parallax
1
2
3
4
5
6
Determining the dimensions of Earth
Eratosthenes (c. 276-194 B.C.)
40,008 km
Solar System – 9 planets
Earth ~ 6.5 Ga People
Earth ~ 4.5 Ga
Milky Way ~ 100 Ga star clusters
Origin of the Earth
p.26-27a
Universe ~ 100 Ga galaxies
How did our Universe Form???
Doppler Effect
Red – low frequency
Blue – high freq.
Hubble & Humason
1929
Expanding Universe
p.26-27a
BIG BANG !!!!!
Nebula – H and He Gas
p.26-27a
Production of heavy elements
by stellar reactions
Supernova
Produces the heavier elements
Our Solar System
Nebular Hypothesis
Multi-Generation Nebula
•Gas – H and He
•Dust
•Ice
p.26-27a
Supernova Disturbance
Supernova Disturbance
Supernova Disturbance
p.26-27a
Gravitational Attraction
Angular Momentum
Centrifugal Force
Centrifugal Force
Protostar
Pressure
Temperature
Nuclear Fusion
Proto-solar system ~ Hubble Image
Planetesimals
Planetesimals
Planetesimals
Solar Winds
A stream of electrons and protons that have
escaped the Sun’s gravitational field
Impact Energy
Gravitational Energy
Organization of our Solar System
Solar System
Inner Planets
Mercury
Venus
Earth
Moon
• Terrestrial planets
• Small rocky bodies very little
volatiles
• Silicates and metals (Fe, Ni)
• Solidified at high temperatures
• Early differentiation - Metallic
cores, Mantle and Crust
• Later developed atmospheres of
volatile gases
Mars
Outer Planets
Jupiter
Saturn
Uranus
Neptune
• “Gaseous Giants”
• Lack solid surface
• Volatile rich (H, He, O) – similar to
constituents of original nebula
• Low temperature solidification
• Thin, flat rings
Pluto
Moon
• 1/3 of Earth’s Diameter
• Density –3.3 g/cm3
• Mare – dark, smooth areas
that make up the lowlands of
large impact basins..basaltic
lava..~4-3 Ga
• Highlands – bright densely
cratered region…~4 Ga
Moon
• 1/3 of Earth’s Diameter
• Density –3.3 g/cm3
• Mare – dark, smooth areas
that make up the lowlands of
large impact basins..basaltic
lava..~4-3 Ga
• Highlands – bright densely
cratered region…~4 Ga
Moon
• 1/3 of Earth’s Diameter
• Density –3.3 g/cm3
• Mare – dark, smooth areas
that make up the lowlands of
large impact basins..basaltic
lava..~4-3 Ga
• Highlands – bright densely
cratered region…~4 Ga