Download Document

Origin of Earth & Life
Kump Ch. 10, T.S. Hamilton
Camosun College
Model Pb Isotope Age for All
Chondritic Meteorites
206Pb
& 207 Pb isotopes are respectively the final daughters
of 238U & 235 U, 207 Pb is common (cosmogenic)
Since the half lives of the 2 Uraniums are constant at ~4.6
Ga and 713 Ma, the slope is a linear growth model for
CM’s formed at the time the Solar System Originated
Earth’s Geological Time Scale
- Earth had liquid water soon after accretion
- Archaea chemoautotrophs were present early
and still persist as primitive extremeophiles
- Cyanobacteria initiate photosynthesis and
create free O2 & O3 !
- Cambrian “Explosion” of Marine HardBodied Animals (all phylla!)
- Devonian Fishes & Plants fully conquer land,
Hi O2 & CO2 atmosphere, hothouse Earth
- Mesozoic: 2nd hothouse Earth, Dinos!
- Cenozoic: last 65 Ma, Mammals and
Angiosperms become dominant
- Homo (sapiens?) last ~2Ma
Eagle Nebula: Pillars of Creation
Hubble
Space
Telescope
A Solar Nebula – Beta Pictoris
Nebula  Solar System
Hertzprung-Russell Diagrams
Log Luminosity versus Wein’s Law
Radiating Temperature
Origin of Moon
- Giant Impact Hypothesis
- Plausible origin for axial tilt
- Wild explanation of iron
core but both planets have
them!
- Differentiation of Earth &
loss of mantle to form
Moon is still favoured
- Big, Close & Fast at first: 56 hour day, huge tides and
Moon same size but 18X
closer!
- Transfer of angular
momentum to moon