Ancient writing has been carbon dated from 3200 BC to possibly 6600 BC.
(from BBC News, 1999)
'Earliest writing' found
"Clay tablets containing primitive words were uncovered in southern Egypt at the tomb of a king named Scorpion.
They were carbon-dated to 3300-3200 BC. This is about the same time, or slightly earlier, to the primitive writing developed by the Sumerians of the Mesopotamian civilisation around 3100 BC."
(From BBC News 2003)
'Earliest writing' found in China
"Signs carved into 8,600-year-old tortoise shells found in China may be the earliest written words, say archaeologists." ...."The site has been radiocarbon dated to between 6,600 and 6,200 BC."
Now, what I am curious about is; How can you tell how old the writing itself is. In other words, lets say you find some material (bone, ivory, tortoise shell) that is 8,000 years old. Lets say, that about 4,000 years ago, when that material was 4,000 years old, an ancient writer also came across it, and decided it would be a good piece of material to write on.
Skip forward to the present day, and the material is carbon dated. Will the writing be considered to be as old as the 8,000 year old material or is there a way to tell how long ago the writing was added to the material?