Tiny volcanic glass shards, or cryptotephra, found in Tasmanian wetland sediments could have originated from a supereruption in Aotearoa over 25,000 years ago – the first time such glass has been identified in Australia. Researchers found the silica-rich volcanic glass about 2.5 m deep in peat and river sediment from the Yellow Marsh, and analysed its chemistry. They estimated its age using radiocarbon dating of plant spores in the sediments above it, and compared its chemistry to the chemical ‘signature’ of glass shards from other eruptions. The eruption it best matched was the Ōruanui supereruption, 25,600 thousand years ago at the site of the present-day Lake Taupō, agreeing with a previous model showing Ōruanui ash may have reached Australia.
