There is beauty in strange places. Think of the perfection of the shell midden, a pile of garbage that now holds interest for those who study archaeology (since garbology didn't sound as sexy).
The garbage label holds especially true when we look at the shell middens from ancient beach sites. Having food “packaging” accumulate in vast heaps around towns and villages is hardly a modern phenomenon. Many First Nations sites were inhabited continually for centuries. The discarded shells and scraps of bone from their food formed enormous mounds called middens. Left over time, these unwanted dinner scraps can transform through a quiet process of preservation. Time and pressure leach the calcium carbonate, CaCO3, from the surrounding marine shells and help “embalm” bone and antler artifacts that would otherwise decay.
Bone already contains calcium carbonate, as well as calcium phosphate, but it is also made of protein, cells and living tissue. Decaying bone acts as a sort of natural sponge that wicks in the calcium carbonate displaced from the shells. As protein decays inside the bone, it is replaced by the incoming calcium carbonate, making makes the bone harder and more durable. The shells also make the surrounding soil more alkaline which also helps to preserve the bone and turns the dinner scraps into scientific specimens for future generations.
