Im looking for any published pollen data from these ice patches. It appears that, the cultural levels are all in some "ice out" area that later became ice covered , the Indians then moved away (Apparently RATHER ABRUPTLY) and these artifacts were encapsulated in the ice.
Now the ice is retreating and all these finds are being made.
Perhaps thay need to carry a flatbed truck with polythene glycol(which is what they flood sprayed all over the VAsa for years inorder to save and harden the wood planks that began to rot the instant that the boat was pulled out of the cold anoxic waters).
Things like clothing and bags and wooden effigies are rare artifacts in Paleo Indian middens due to rapid decay.