GEOL3045: Planetary Geology
GEOL3045: Planetary Geology
Lysa ChizmadiaEarth-Moon System
Lysa ChizmadiaEarth-Moon System
IntroductionIntroduction Earth is 3rd planet from
the Sun First with natural satellite
Largest planet in inner solar system Diameter = 1.3 x 104 km
Highest density 5.52 g/cm3 FeNi core 1/6 ’s volume > Mars
Youngest surface Weathering Plate Tectonics
Earth is 3rd planet from the Sun First with natural satellite
Largest planet in inner solar system Diameter = 1.3 x 104 km
Highest density 5.52 g/cm3 FeNi core 1/6 ’s volume > Mars
Youngest surface Weathering Plate Tectonics
Image from: http://www.nineplanets.org/earth.html
Image from: http://en.wikipedia.org/wiki/Earth
Plate TectonicsPlate Tectonics Three types of plate
boundaries Divergent Convergent Transform
Explains distribution of e-quakes & volcanoes
Driven by convection Primordial heat from
Accretion Radioactive decay Core crystallization
Three types of plate boundaries Divergent Convergent Transform
Explains distribution of e-quakes & volcanoes
Driven by convection Primordial heat from
Accretion Radioactive decay Core crystallization
Image from: http://en.wikipedia.org/wiki/Earth
Image from: http://www.nineplanets.org/earth.html
Divergent BoundariesDivergent Boundaries AKA
Spreading Center
AKA Rifts Largest
Mountain Chains in Solar System
Plates move apart due to eruption of lava
New lava = new oceanic crust
AKA Spreading Center
AKA Rifts Largest
Mountain Chains in Solar System
Plates move apart due to eruption of lava
New lava = new oceanic crust
Continental RiftingContinental Rifting
Convergent BoundariesConvergent Boundaries
AKA Destructive Boundaries
AKA Subduction Zones Old oceanic crust dense &
heavy Heavy vs. light =>
subduction
Three Types: Ocean-ocean Ocean-continent Continent-continent
AKA Destructive Boundaries
AKA Subduction Zones Old oceanic crust dense &
heavy Heavy vs. light =>
subduction
Three Types: Ocean-ocean Ocean-continent Continent-continent
Transform BoundariesTransform Boundaries AKA
Conservative Plate Boundary
Plates slide past each other Fracture zones
in Mid-ocean ridges
Strike-slips faults Only e-quakes
No volcanoes
AKA Conservative Plate Boundary
Plates slide past each other Fracture zones
in Mid-ocean ridges
Strike-slips faults Only e-quakes
No volcanoes
Hot SpotsHot Spots
Caused by mantle plumes
Plumes do not move, plates do Leaves track of
ocean islands Bend at 40Ma
Major change in plate motion
Caused by mantle plumes
Plumes do not move, plates do Leaves track of
ocean islands Bend at 40Ma
Major change in plate motion
Atmosphere & Hydrosphere
Atmosphere & Hydrosphere Atmospheric Layers
Water Cycle Both act to weather
surface Surface is Young!
Atmospheric Layers Water Cycle Both act to weather
surface Surface is Young!
Image from: http://www.nineplanets.org/earth.htmlImage from:http://www.solcomhouse.com/atmosphere.htm
WeatheringWeathering Mechanical
Weathering Physical breakdown
of rocks into smaller pieces
Chemical Weathering Chemical reactions
which act to dissolve minerals into aqueous ions
Presence of water near triple point
Mechanical Weathering Physical breakdown
of rocks into smaller pieces
Chemical Weathering Chemical reactions
which act to dissolve minerals into aqueous ions
Presence of water near triple pointImage from: http://www.lsbu.ac.uk/water/phase.html
Image from: http://www.sv.vt.edu/classes/MSE2094_NoteBook/96ClassProj/examples/triple.html
The MoonThe Moon Distance from
3.8 x 105 km Orbit around
27.3 days (tidally locked) Rotation (phases)
29.7 days Density = 3.35 g/cm3
Due to size & composition, considered a terrestrial planet
Surface Composition Bright Highlands (82%)
CaAl2Si2O8
Dark Maria (18%) Basalt
Distance from 3.8 x 105 km
Orbit around 27.3 days (tidally locked)
Rotation (phases) 29.7 days
Density = 3.35 g/cm3
Due to size & composition, considered a terrestrial planet
Surface Composition Bright Highlands (82%)
CaAl2Si2O8
Dark Maria (18%) Basalt
Image from: http://www.solarviews.com/eng/earth.htm
Images from: http://en.wikipedia.org/wiki/Moon
Near Side
Far Side
TidesTides Spring tide: when Earth, Moon &
Sun aligned Neap tide: Moon perpendicular to
Sun
Spring tide: when Earth, Moon & Sun aligned
Neap tide: Moon perpendicular to Sun
SummarySummary Earth
Plate Tectonics Divergent Plates Convergent Plates Transform Plates Hot Spots
Complex Atmosphere Hydrosphere
=> Weathering => Young surface
Surface composition Oceans = Basalt Continents = Granite
Earth Plate Tectonics
Divergent Plates Convergent Plates Transform Plates Hot Spots
Complex Atmosphere Hydrosphere
=> Weathering => Young surface
Surface composition Oceans = Basalt Continents = Granite
Moon (Luna) Terrestrial Planet
B/c size & composition Low Density
Little or no FeNi core Tidally locked to Earth
Always see same side Pulls on oceans & crust
Surface composition Anorthosite Basalt
Old Surface Heavily cratered No weathering
Moon (Luna) Terrestrial Planet
B/c size & composition Low Density
Little or no FeNi core Tidally locked to Earth
Always see same side Pulls on oceans & crust
Surface composition Anorthosite Basalt
Old Surface Heavily cratered No weathering