Open Access Te Herenga Waka-Victoria University of Wellington
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Providing a Tephrochronological Framework for 10Myrs of Deposition in the Wairarapa

posted on 2024-04-25, 22:59 authored by Libby O'Brien

The Wairarapa lies within a fore-arc section of the Hikurangi Margin, New Zealand. Since the Late Miocene the depositional environment here has developed from deep marine to fluvial and terrestrial settings as a result of the emergence of Aotearoa, New Zealand's (ANZ) landmass. Superimposed on this record of shallowing and emergence is a series of cyclothems which reflect sea level changes during glacial and interglacial periods. Active volcanism which continued from $\approx$22 Ma through to the present day resulted in the deposition of 40 observed tephra deposits from in the Wairarapa. These encompass activity from the Coromandel Volcanic Zone, Tauranga Volcanic Zone and Taup\={o} Volcanic zone since 22Ma and provide opportunity for region wide, temporal correlation of the Wairarapa's sedimentary record. In order to constrain sedimentation rates and depositional ages this study uses modern tephrochronological techniques such as EPMA and LA-ICP-MS point analysis to analyse the geochemical composition of glass, as well as U-Pb-Th radiometric dating of zircons to determine zircon crystallisation ages for 40 deposits from the Wairarapa region. Overall, this study provides new geochemical data for 25 of the 40 sampled deposits as well as five new absolute ages which provide the basis for a new tephrochronological framework for 10 Myrs of deposition the Southern Wairarapa.


Copyright Date


Date of Award



Te Herenga Waka—Victoria University of Wellington

Rights License

CC BY-ND 4.0

Degree Discipline


Degree Grantor

Te Herenga Waka—Victoria University of Wellington

Degree Level


Degree Name

Master of Science

ANZSRC Socio-Economic Outcome code

280107 Expanding knowledge in the earth sciences

ANZSRC Type Of Activity code

1 Pure basic research

Victoria University of Wellington Item Type

Awarded Research Masters Thesis



Victoria University of Wellington School

School of Geography, Environment and Earth Sciences


Hopkins, Jenni; Carroll, Dene; Hannah, Michael