Researcher uses carbon dating
This information has also helped determine the age of the Earth itself.While the oldest known rocks on Earth are about 3.5 billion years old, researchers have found zircon crystals that are 4.3 billion years old [source: USGS].
But this sediment doesn't typically include the necessary isotopes in measurable amounts.According to the authors' estimates, the ice was about 120,000 years old.Study authors say they now want to find older ice."Most people assume that it's a question of just drilling deeper for ice cores, but it's not that simple," said study coauthor Edward Brook, an Oregon State University geologist.Fossils can't form in the igneous rock that usually does contain the isotopes.The extreme temperatures of the magma would just destroy the bones.Because there's so little krypton in the air, you have to melt down a lot of ice to obtain sufficient samples.
Also, you need a device that can count, or trap, individual atoms.
This is what archaeologists use to determine the age of human-made artifacts. The half-life of carbon-14 is only 5,730 years, so carbon-14 dating is only effective on samples that are less than 50,000 years old.
Dinosaur bones, on the other hand, are millions of years old -- some fossils are billions of years old.
By using radiometric dating to determine the age of igneous brackets, researchers can accurately determine the age of the sedimentary layers between them.
Using the basic ideas of bracketing and radiometric dating, researchers have determined the age of rock layers all over the world.
To determine the ages of these specimens, scientists need an isotope with a very long half-life.