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12 Cards in this Set

  • Front
  • Back
how did oceans first start
outgassing water vapor from rocks and then condensation
when did water first occur
3.8 bya
wat was the % of current oxygen occured in diff sec of the precambrian
1% occured in hadean
10% occured in archean
proterozoic same as current oxeygen lvls
where did the first crust begin to occur
at subduction zones
name of oldest rock and how old is it
acasta gneiss, 4.03 bya
archaen techtonics
small continent masses
plate tech rapid movement
growth by accretion
wen was most of the crust form
2.5 bya
wat is the proterozoic eons and how are they divided
neo - 1.0 bya - 545 mya
meso - 1.6 - 1.0 bya
paleo - 2.5 - 1.6 bya
wat is the wilson cycle
This cycle of opening and closing ocean basins
how long did oxeygen begin the to get to rich in oceans and iron percipitated
wat was tempertures of snowball eart
-40 C
what is life
reproduction - long term
metobolic - life of individual