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WELCOME TO GG
101
PHYSICAL
GEOLOGY
My name is Patty Lee.
We meet Monday , Wednesday
and Friday from 10:30 to 11:20.
SHOW UP!
We will study the PHYSICAL
characteristics or the
GEOLOGY of our planet,
EARTH.
WHAT IS GEOLOGY?
 logia
(study) of the geo (earth)
HOW DO WE STUDY IT?
 directly
& indirectly using the scientific method
WHY DO WE STUDY IT?
To figure out how Earth
works!
 resources
 environment
 hazards




RESOURCES
HAZARDS
ENVIRONMENT
BEAUTY
2 MAJOR CONCERNS

GEOLOGIC TIME

ENERGY
GEOLOGIC TIME
ARISTOTLE
 FAST TIME
 SLOW TIME
 BISHOP USSHER
 JAMES HUTTON
 CATASTROPHISM
 UNIFORMITARIANISM
 WORLD-WIDE &
 THE PRESENT IS THE
SUDDEN DISASTERS
KEY TO PAST
Siccar Point, Scotland
Fig. 1.3
Geologic Time Scale
Geologic
Time
Scale
ENERGY
 GIANT MACHINE (EARTH) DRIVEN BY
 2 ENGINES -> HEAT ENGINES:
EXTERNAL ENGINE
INTERNAL ENGINE
EXTERNAL ENGINE - SUN
• 60% OF SOLAR
ENERGY IS USED TO
DRIVE WEATHER
SYSTEM BY VARIABLE
HEATING
• HYDROLOGIC CYCLE
-> EVAPORATION
• JOB IS TO FLATTEN
THE SURFACE OF
EARTH BY
WEATHERING,
EROSION &
INTERNAL ENGINE
• HEAT FLOWS FROM
HIGH TO LOW
TEMPERATURE
• FROM INSIDE TO
OUTSIDE OF EARTH
• JOB IS TO BUILD
VOLCANOES,
MOUNTAINS,
MOVES PLATES ->
PLATE TECTONICS
HOW HEAT WORKS
• WORKS IN 2 WAYS -> CONDUCTION &
CONVECTION
• ROCKS BEHAVE PLASTICALLY (wax, soft tar)
• GEOTHERMAL GRADIENT -> ~1deg.C/40M
THE UNIVERSE
BIG BANG

UNIVERSE COMPOSED OF
HYDROGEN (76%)
 HELIUM (23%)
 ALL ELSE (1%)


Hubble DEEP FIELD
<origins.jpl.nasa.gov/
poster/
deepfield.html>
THE SOLAR SYSTEM
 SOLAR NEBULAR




FORMED 4.55 BILLION
YEARS AGO AS
PLANETESIMALS
COALESCED INTO
PLANETS
4 INNER ROCKY
PLANERS AND 4 GAS
GIANTS + PLUTO
HEATED BY IMPACTS
OF NUBULAR DEBRIS
CAUSING PLANETS TO
DIFFERENTIATE
The origin of the solar system.
A catastrophic impact between the proto-Earth and a
Mars-sized impactor.
Heating and
differentiation of
the early Earth.
EARTH - OUR ISLAND HOME
The
Three
States of
Water
(Why Earth is
so special)
A
model
of the
Earth’s
interior.
OK!
SO WHAT?
WE HAVE ALL THIS
INFORMATION
BUT
WHAT DOES IT MEAN?
WHAT IS PLATE TECTONICS?
LET’S FIND OUT!
PLATE TECTONICS
• UNIFYING THEORY of plate motion
• PLATES - 7 major plates & many minor
plates
• MOVE with respect to each other as fast as
finger nails grow
• **remember that crust rides in lithosphere
over the asthenosphere**
• Three (3) kinds of PLATE MARGINS
DIVERGENT MARGIN
<-SPREADING->
• Plates move apart leaving a gap that is filled by
magma/lava making new sea floor & new plate
• Occurs at Divergent Margins (MOR)
• Mid-Ocean Ridges (MOR) are elevated submarine volcanic mountains
CONVERGENT MARGIN
->SUBDUCTION OR COLLISION<• Deep sea trenches
where subducting
plates move into
Earth’s interior
• Oceanic crust is
SUBDUCTED,
destroyed
• Continental crust
COLLIDES and builds
mountains
TRANSFORM MARGINS
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GIF decompressor
are needed to see this picture.
• Plates slide horizontally past each other at great
vertical faults
• Plates scrape & deform margins as they move
• Crust is neither created nor destroyed
Earthquakes & Plate Margins
WHY ALL THIS ACTIVITY?
Just what drives the plates?
• CONVECTION CURRENTS - transfers heat from
inside to surface - plates ride the currents
• RIDGE-PUSH - upwelling pressure so great at
MOR that forces plates to split
• SLAB-PULL - cooled slabs are so heavy that drag
plate down a subduction zone-gravity assisted
• RIDGE MASS - mass is so great @ MOR that
forces plates to move away
• MANTLE PLUMES - locally concentrated
upwellings, lateral flow, slow downwelling
SYSTEMS - Run by energy & made of matter
1.
Definition: ANY PORTION OF THE UNIVERSE
SEPERATED FROM THE REST OF THE
UNIVERSE FOR THE PURPOSE OF OBSERVING
CHANGES

It is implied that all systems have boundaries

The amount of matter in a closed system is fixed!

Systems are composed of SUBSYSTEMS which
are in DYNAMIC BALANCE
Kinds of Systems
The Earth
is a Closed
System
CYCLES - Group of processes that
move matter and energy between
subsystems
HYDROLOGIC CYCLE - driven by Sun and works on
surface
ROCK CYCLE - 3 families defined by formation processes
IGNEOUS ROCKS - “born of fire”; melted rock->
MAGMA
SEDIMENTARY ROCKS - formed at surface from rock
fragments
METAMORPHIC ROCKS - altered preexisting rock
material
TECTONIC CYCLE - moves rock material between
surface & Earth’s interior by interaction of tectonic
plates; run by internal heat
The 3 Major Cycles
IRON CATASTROPHY
STRUCTURE OF EARTH