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3 Cards in this Set
- Front
- Back
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Name three methods to data rocks |
Radioactive dating Law of superposition Palaeomagnestism |
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Describe how radioactive dating works? |
Radioactive dating via the decay of radioactive isotopes This provide absolute ages e.g years Living things take C from the atmosphere hence have the 14^C / 12^C ratio When they die 14^C decays into 14N,but the amount of 12^C stays the same We know the rate of 14C decay(half life)so we can work out how long ago an organism died |
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Describe laws of superposition |
In under formed stratigraphic sequences in sedimentary ,the oldest stata (rock later) will be at the bottom of the sequence and the youngest at top Provides relative age,not absolute age The fossils presented in the rock can be used to estimate a specific time period |
