25 terms

dating using atoms

radioactive decay
the spontaneous nuclear change of isotopes with unstable nuclei
the time it takes for a given amount of a radioactive isotope to be reduced to one-half
how long ago was the palezoic era?
540 million years
how long ago was the mezoic?
220 million years
closed system
when we have one mineral in the rock which formed along with the rock
metamorphic rock
formed by the recrystallization of rocks due to high temp or pressure
what are the three grades of metamorphism?
high, low, or mid
what is the best rock to date?
what does 14CN date?
organic materials
what time period does 14 CN date?
less than 40,000
what does K-AP date?
feromagnisium minerals and K-feldspar
what time period does K-AP date?
greater than 100,000
what does UPB date?
felsic minerals
what time period does UPB date?
greater then 100 million years
a normal fault where hanging wall is moving down and footwall is moving up
strike slip
like a transform fault
what is an example of strike-slip?
Saint Andreas fault
what happens when a normal fault is uplifted and elongated
what happens if a normal fault undergoes extension
a garben at mid-ocean ridges
what type of pressure do reverse faults form under?
what are the 4 types of metamorphism?
1) burial 2) regional 3) contact 4) fault zone
isotopic dating
determining the age of a rock through its radioactive elements
parent isotope
the original isotope
daughter isotope
the new isotope that is formed