Checked the whole southern Andes ash database against the 1458 glass

Found the open BOOM database of southern Andean ash on GitHub and scored all 39 eruptions with enough rhyolite analyses. Nothing matches well, and none of the eruptions dated near the 1400s fits at all. Combined with the New Zealand and Antarctic checks, the 1458 rhyolite matches no known eruption anywhere we can test. That is as far as public data goes; the next step needs trace-element analyses of the ice shards or new lake cores from Patagonia.