Crossing new frontiers: extending tephrochronology as a global geoscientific research tool

Abstract

Tephrochronology is a unique stratigraphic tool for linking, dating, and synchronising geological, palaeoenvironmental, or archaeological sequences and events (Lowe, 2011; Alloway et al., 2013). It relies on the identification and tracing of tephra or cryptotephra horizons spatially between various depositional sequences. These horizons can provide stratigraphic event layers (tephrostratigraphy) and, when dated, isochronous age markers — since most tephra are deposited on a scale of days to weeks — that can be transferred from site to site (tephrochronology) (Lane et al., 2017b). The correlation of horizons between different sequences is reliant on matching the physical characteristics, mineralogical assemblages, and geochemical compositions of minerals and/or glass shards in tephra deposits using a range of analytical methods and visual and statistical approaches (e.g. Lowe et al., 2017). Correlating tephra deposits back to their volcanic source allows tephrochronological studies to provide information on the eruption frequency and geochemical evolution of volcanic regions and individual volcanoes.