Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Radiometric Dating

  1. Apr 22, 2005 #1
    You can date a rock by measuring the ratio of a parent isotope and its daughter. But you can only determine when the rock was formed if you know the ratio of parent to daughter isotopes when it was formed. So how is that ratio known?
  2. jcsd
  3. Apr 22, 2005 #2
    you assume that all daughter product is radiogenic, formed from radioactive decay process.
  4. Apr 22, 2005 #3
    Take potassium-argon dating. Potassium 40 decays into argon 40, a gas, which can diffuse through lava and escape. Newly formed igneous rocks has essentially no argon 40. It's only when the rock solidifies that the argon becomes trapped and begins to accumulate.
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Similar Threads - Radiometric Dating Date
Uranium-Lead Dating Jun 12, 2017
Cool examples of radiometric dating? Feb 21, 2013
Radiometric dating of items with a known age Jun 2, 2012
Carbon dating converter INTCAL09 Apr 24, 2012
Dating methods Apr 18, 2009