Maximum effective dating range for carbon 14 dating
We can get reasonable accuracy to 50,000 years, better accuracy more recently.This calibration is what limits the accuracy because we know that with a given amount of carbon-14, it absolutely will decay at a very tightly controlled rate.100,000 years is out of the question. It can set a frame, or a parameter for the occurence of one event or another, but it has only the most recent reference for the age of any matter whatsoever. We have only arbitrary concepts of the age of matter as we know it. The theory being that once the material (presumably organic) has trapped the 'day zero' carbon-13/-14 mix in it's molecules that mix ratio begins to change.To do that we need samples of atmospheric gas, from ice cores or solar activity from tree rings, etc.If we're a bit depleted in nitrogen-14, then we know it's become carbon-14.It'd have to be, it's what controls radioactivity and all other nuclear reactions.
K-Ar Decay Profile Clicking on the "Show Movie" button below will bring up an animation that illustrates how a K-Ar sample is processed and the calculations involved in arriving at a date.If it has generally been established as a constant, at what point does the "constant" break down?