principle of superposition
old on the bottom young on the top
principle of original horizontality
every layer starts out horizontal.
principle of cross cutting relationships
james hutton discovered that the new rocks cut the old. You have to put the relationships at the end or will get it wrong
principle of fossil succession
also Faunal Succession. William Smith. Organisms change from simple to complex over time
principle of Inclusion
also James Hutton. Fragments in a rock body are older than the rock that contains them
Difference between relative and absolute dating
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
what is angular unconformity
sedimentary rock layers that are not horizontal due to deposition deformation erosiaon and renewed deposition.
what is disconformity
sedimentary rock the beds are horizontal
what is nonconformity
sedimentary rock in contact with metamorphic or igneous rock
who invented radio activity
henri becquerel in 1896
what is half life
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
what is the nebular hypothesis
the earth and solar system formed from an exploded star
how were oceans created
what is accretion
coming together of smaller ilandmasses into larger ones.
what were the prokaryotes
Blue Green algae which produced tons of caco3 called stromatolites
when was precambrian era
4.6 billion to 570 million years ago
order of eras