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# Isotopic age dating patterson

So to figure out the age of the Earth, we have to look somewhere else... Earth has a molten magma layer and plate tectonics, so the "closed system" requirement of these radiometric dating methods is sometimes difficult to satisfy for Earth itself.Meteorites, on the other hand, have been floating around in space since the solar system was formed.When they come crashing to Earth, analysis of their composition can be geologically analyzed.Claire Patterson was the first to accurately date the crystallization of Earth to 4.55 /- 0.05 billion years ago.The animation in Figure 2 shows the flat line and how it increases with time. It works because Sr86 is stable and not radiogenic and therefore stays constant with time.The isochron method can determine the age of any rock, but new rocks are formed all the time.

### live link dating You may have heard that the Earth is 4.54 billion years old. If the half-life of a material is 100 years and you have 1 kg of it, 100 years from now you will only have 0.5 kg of it.This was calculated by taking precise measurements of things in the dirt and in meteorites and using the principles of radioactive decay to determine an age. The rest will have decayed into a different nuclide (called a nuclide).Several radioactive nuclides exist in nature with half-lives long enough to be useful for geologic dating.Parts of the rock that have more Rb87 will end up with more Sr87.

By measuring a few samples of the rock and comparing the relative amounts of Sr87 and Rb87, we can figure out how old the rock is! If you think about it, the equation above is a lot like the formula for a line, $$y=mx b$$ with $$y=\text_$$, $$m= \left(e^-1 \right)$$, $$x=\text_$$, and $$b=\text_$$.

This is the key to figuring out how much time has passed since the rock solidified.