Comment by mncharity
10 hours ago
> no real reason [...] still coated in whatever was floating around the environment
I wonder, might one instead make an argument that it's not currently economic-technologically feasible to avoid artifact surface information destruction and contamination, at any stage of the dig-to-archival-conservation pipeline, nor to extract whatever information might be there, outside of very rare cases? Rather than there's no information there to lose?
Perhaps it becomes possible-and-affordable at some point, to frequently check, say, "oh neat, here are some 10 um notches on the surface, with some nice yeast, and some pollen, and oh, maybe that's a bit of calcified biofilm for nanopore DNA?"? Does automated lab tech progress, someday make "brushed, handled, dusted, washed, and shelf in the basement" start sounding like 19thC "we accessed the site using dynamite"?
Nowadays they don’t in fact brush off artifacts immediately upon extraction, just clear them of large clumps of dirt. Precisely because the fragile remains of paint and whatever else might have been stuck to them can often teach us more than the artifact itself.
That one notch further on the spectrum that’s being described. Will “clear large chunks of dirt in the field” be found to have damaged information? Is there genuinely nothing to learn from the chunks of dirt? Or is it still too expensive to pay attention?
We can only understand the coarsest information available in the soil. Any particular cubic centimeter has thousands of completely undocumented bacterial taxa, miles of fungal threads, organic residues left behind by higher lifeforms, etc. Each bit of soil is essentially unique.
Moreover, just being in the general vicinity is enough for us to leave behind contamination, since humans (and all other animals) constantly shed detectable eDNA into the environment. And even if they wanted to deal with this complexity, the budget for an entire project's archaeological testing is often less than my coworkers' monthly token budgets. You might get less than a dozen radioisotope, TL, or dendro tests for the entire thing, let alone anything more expensive.