Is there anything more accurate than carbon dating?

Carbon dating is only effective to about 50,000 years. After that, all of the original carbon-14 has gone. So if you want to date something that is on a geological timescale, you might choose potassium-40, with a half-life of 1.2 x 10^9 years. Uranium-238 is 4.61 x 10^9 years, so it is good for even longer timescales. In short, for radioisotope dating, you need an isotope that shows significant decay over the period you are investigating