Microanalysis of Fine Insoluble Particulates from the Colle Gnifetti Ice Core

New methodological advancements allow for the capture and quantitative analysis of fine (5-10 mum) and ultra-fine (< 4mum) insoluble particles from an ice core. This study examined several intervals from the Colle Gnifetti ice core, targeting deposits that were tied to volcanic eruptions using glaciochemical signatures. We used SEM/EDS to analyze all materials and the NIST DTSA-II methodology and software to provide fully quantitative data. One interval, from 57.67-57.88 meters, had dust, minerals, and three (5-8 mum) rhyolitic tephra particles. According to the existing timescale developed using annual layer counting, this interval corresponds the late 400s CE. These tephra particles will help to confirm the existing timescale by providing tephrochronological context for the ice core, as well as, once a specific Icelandic source eruption is determined, provide context for atmospheric circulation at the time of …