This does not mean that the pre-Clovis layers were perfectly undisturbed — no cave sediment is.

It means that the level of disturbance was insufficient to undermine the basic stratigraphic interpretation that the deepest layers contained material that was deposited before the Clovis horizon.

The Interaction Between Evidence Types

One of the most intellectually satisfying aspects of the Paisley Caves research program is the way in which different types of evidence have been brought into dialogue with each other, each addressing questions that other types of evidence cannot answer alone.

The radiocarbon dates establish when things happened — or, more precisely, they establish the probability distribution of when specific organic materials were alive.