How do those who believe in a 6000+ year old earth explain the MUCH OLDER countable layers of polar ice cores?

Well carbon dating and radio-isotope dating methods are flawed to begin with because its based on an initial umption of something being a certain age. You need a standard to measure off of but how are you able to confirm the age of one thing by going by something else that you cant confirm whether or not the age of that item is correct?