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