Greenland Ice Cores

Although your claim was already refuted in the first message in this thread, see also Creationist Comedy.

Yes, many times, over and over and over again. They've been tested six ways from Sunday and cross-correlated to a fare-thee-well and passed every test. Care to start a thread on radiosotope dating in the proper forum and see who's really ignorant? Better be prepared to discuss isochron dating, concordia-discordia dating, quantum physics as it applies to radioactive decay, the Oklo reactor, the decay of radioactive cobalt in SN1987A, and a few other topics ... but don't bother to bring up potassium-argon dating. (And if you don't know why you shouldn't bother to bring up K-Ar dating then you are not qualified to have a serious discussion).

That's the oldest rocks ... the oldest minerals that we've found are zircons that are 4.3 to 4.4 billion years old. See Earlier Water on Earth? Oldest Rock Suggests Hospitable Young Planet.Lead-lead isochrons (another variant of uranium series dating) is used on meteorites and terrestrial rocks to obtain the generally accepted age of the Earth: about 4.55 billion years.

Nitpicking in creationist mode, the relationship between counted layers and years is based on a scientific theory (albeit an excptionally well supported one).

But that doesn't stop a creationist from denying the layer-to-year relationship because he/she didn't personally observe every layer forming.