"At the end of its uselife, the megalithic enclosures of Göbekli Tepe were refilled systematically. This special element of the site formation process makes it hard to date the enclosures by the radiocarbon method, as there is no clear correlation of the fill with the architecture. Several ways have been explored to overcome this situation, including the dating of carbonate laminae on architectural structures, of bones and the remains of short-lived plants from the filling. The data obtained from pedogenic carbonates on architectural structures back the relative stratigraphic sequence observed during the excavation. But, unfortunately, they are of no use in dating the sampled structures themselves, as the carbonate layers started forming only after the moment of their burial. At least these samples offer a good terminus ante quem for the refilling of the enclosures. For layer III this terminus ante quem lies in the second half of the 9th millennium calBC, while for layer II it is located in the middle of the 8th millennium calBC."
https://www.researchgate.net/publication/258182967_Radiocarb...