The Story of Earth

The First 4.5 Billion Years, from Stardust to Living Planet

Robert M Hazen, Central, 550 H4299s 2012

• p96 ZrSiO4 zircons durable, uranium atoms decay to lead with 4.5 GY halflife, dating the crystals

• p97 Water lowers the temperature at which zircons grow, causes higher O₁₈ to O₁₆ ratio, surface water does also

  • Jack Hills Australia, 4.4 GY old zircon, oldest known surviving solid fragment of Earth, so there were oceans then
• p98 ~100 MY after Tethys, global mile-deep ocean
• p126 smaller protocontinents 3 GYa
• p177 2/3 of the current 4500 mineral types require oxygen (from life, in subsurface waters) to form
  • i.e. turquoise, azurite, malachite
  • minerals deriving from copper, uranium, iron, manganese, nickel, mercury, molybdenum, and others

  • Mineral Evolution

• p178 Mars does NOT have this mineral diversity, the scarce water is frozen
  • surface oxidized iron is "like a coating of paint", oxidized by disassociated water and escaped hydrogen
• p179 continents significantly smaller 2 GYa, also rusty red

• p190 United Plates of America, Laurentian supercraton a conglomeration of > 6 large cratons

• p226 Dominic Papineau, anoxic dead zones from fertilizer runoff
• p263 10ppm chance of death by asteroid impact
  • 300 meter Apophis will cross close by in 2029
  • 8 meter rock every year
  • 30 meter rock 1e-3 per year, Tunguska
  • 800 meter 2e-6/y
  • 5000 m rock 1e-7/y
  • 10000 m Chixulub
• p266 Mars colony as alternative (?), one way trip
  • but where does the industry and minerals come from
• p268 Loihi submerged 2 mile high southwest of Hawaii, emerging in a million years