Geologic Time

  • 4.5 billion years ago to the present day

Relative Geologic Time

  • a sequence of geologic events but in the order they occurred in

Absolute Geologic Time

  • giving the numeric age of a geologic event

Nicholas Steno

Charles Lyell

1) Law of Superposition

  • Oldest on the bottom

  • youngest on the top

Igneous Intrusions

2) Law of Cross-cutting Relationships

3) Law of Inclusions

  • pieces of one rock inside another

  • Inclusions are always the older rock

Working with Radiation LMAO

  • lowk not for normal people

  • if you like ts you may be a geologist or suicidal

  • bc playign with radioactive stuff is no joke

Absolute Geologic Time

  • Isotopes

  • Radioactive isotops

  • Tritum = radioactive parent

  • half life = the amount of time it takes for ½ parent isotope (tritium) to decay to the stable daughter isotope (deuterium)

Trituum/Deuterium = 12 years

  • with each half life

    • half of what you started with (i couldn’t hear the last part)

“I was born when I was a babe” - Dr. Bennet

uranium / Lead = 4.5 Billion years

Look up radioactive decay curve