Tephrochronology in Aotearoa New Zealand

Tephra deposits in Aotearoa New Zealand (ANZ) have been studied for >180 years. The now-global discipline of tephrochronology, which has some developmental roots ANZ, forms the basis a powerful chronostratigraphic correlational tool and age-equivalent dating method geological, volcanological, palaeoenvironmental, archaeological research ANZ. Its utility is founded on key principle that tephras or cryptotephras provide widespread isochrons many different environments. In first part this article, we summarise history tephra studies ANZ then describe how mapped, characterised, correlated using field laboratory-based methods. We document advances geochemical fingerprinting glass; tephra/cryptotephra detection correlation by sediment-core scanning methods (e.g. X-radiography, CT imaging, XRF elemental analysis, magnetic susceptibility); statistical methods; tephras/cryptotephras. discuss advent cryptotephra (from mid-1970s) their more-recent growth. second comprises examples applications tephrochronology ANZ: climate-event stratigraphy (NZ-INTIMATE project); eruptive-event Auckland Volcanic Field; developments marine record; identifying, correlating, old (pre-50 ka) weathered-tephra deposits; forming soils/paleosols tephras; archaeology; Kopouatai bog tephrostratigraphy palaeoenvironments; volcanic-hazard assessments.