geologic time

old on the bottom young on the top

every layer starts out horizontal. 

james hutton discovered that the new rocks cut the old. You have to put the relationships at the end or will get it wrong

also Faunal Succession. William Smith. Organisms change from simple to complex over time

also James Hutton. Fragments in a rock body are older than the rock that contains them

• relative uses the 5 principles and just puts things in chronological order. it does not use any numerical ages.
• absolute uses radiometric methods to get an exact age

sedimentary rock layers that are not horizontal due to deposition deformation erosiaon and renewed deposition.

sedimentary rock the beds are horizontal

sedimentary rock in contact with metamorphic or igneous rock

henri becquerel in 1896

• the rate of decay for an isotope.
• every time the isotope decays in half the same time has gone by regardless of the size
• Exponential NOT Linear

the earth and solar system formed from an exploded star

outgassing

coming together of smaller ilandmasses into larger ones.

Blue Green algae which produced tons of caco3 called stromatolites

4.6 billion to 570 million years ago

• precambrian
• paleozoic
• mesozoic
• cenozoic