Mathematically, P = Po exp(-lambda T), where lambda = the decay constant and T = the period of decay. a zero initial number of D atoms, where P(or D) = the current number of P(or D) atoms, it follows that the age of a rock or mineral is computed as T=(1/lambda)ln(1 D/P).
Using radiometric techniques, the oldest dated minerals (4.0 - 4.2 billion years) are zircon crystals found in sedimentary rocks in western Australia.
This challenge is mainly headed by Creationism which teaches a young-earth (YE) theory.
A young earth is considered to be typically just 6,000 years old since this fits the creation account and some dating deductions from Genesis.
One problem with earth dating is that the original earth surface is assumed to have eroded long ago.
But assuming the earth was formed at the time of the rest of our solar system, then recovered moon rock and meteorites can also be used to estimate the age of the earth.
Dating Anomalies Here we outline a few dating methods or 'clocks' that present a dating anomaly when referenced to the widely accepted OE age of 4.6 billion years. At the outset we note C-14 cannot be used to directly date the earth for the simple reason that the unstable C-14 isotope has a half-life of just 5,730 years.In fact, organic samples from every portion of the Phanerozoic record (spanning the last 500 million years on OE dating) show detectable amounts of C-14.The implication is that this organic material was either contaminated by new C-14, or it was buried much more recently and OE dating methods are suspect.The technique gave 90 million years, but took no account of the non-constant erosion rate, or the loss and recycling of salt, or the fact that salt is obtained from other sources as well as continents.More recently, work has been done on ocean sediments [S. This suggests that, given the current annual rates of erosion (some 27.5 billion tons), all earth's continents would be delivered into the oceans in just 14 million years.
Absolute dating supplies a numerical date whilst relative dating places events in time-sequence; both are scientifically useful.