How accurate is carbon 14 dating
The differences actually found in the scientific literature are usually close to the margin of error, usually a few percent, not orders of magnitude!Vast amounts of data overwhelmingly favor an old Earth.Also, as the authors of the 1968 article were careful to explain, xenoliths cannot be dated by the K-Ar method because of excess argon in bubbles trapped inside [Dalrymple2006].Thus in this case, as in many others that have been raised by skeptics of old-earth geology, the "anomaly" is more imaginary than real.147] has highlighted the fact that measurements of specimens from a 1801 lava flow near a volcano in Hualalai, Hawaii gave apparent ages (using the Potassium-Argon method) ranging from 160 million to 2.96 billion years, citing a 1968 study [Funkhouser1968].In the particular case that Morris highlighted, the lava flow was unusual because it included numerous xenoliths (typically consisting of olivine, an iron-magnesium silicate material) that are foreign to the lava, having been carried from deep within the earth but not completely melted in the lava.A recent survey of the rubidium-strontium method found only about 30 cases, out of tens of thousands of published results, where a date determined using the proper procedures was subsequently found to be in error.One question that sometimes arises here is how can scientists assume that rates of radioactivity have been constant over the great time spans involved.
And it has been close to a hundred years since the uranium-238 decay rate was first determined.
The isochron techniques are partly based on this principle.
The use of different dating methods on the same rock is an excellent way to check the accuracy of age results.
Another method is to make age measurements on several samples from the same rock unit.
This technique helps identify post-formation geologic disturbances because different minerals respond differently to heating and chemical changes.