Abstract

Correlation and dating of widespread rhyolite tephras erupted from Taupo Volcanic Zone, North Island, New Zealand, provides remarkable opportunities for correlating marine and terrestrial records of Quaternary environmental changes. Tephrostratigraphy, magnetostratigraphy and biostratigraphy of emergent marine sediments in Wanganui Basin allows correlation of strata to the isotope record of deep sea cores, with a precision of better than one isotope stage. Radiometric ages for several tephras are consistent with the astronomically calibrated isotope stage chronology of Shackleton et al. (1990). Pollen assemblages and oxygen isotope analyses from marine cores indicate that terrestrial vegetation changes in New Zealand were closely linked with global climatic changes. Major glaciations in the South Island were also closely synchronous with glaciations in the Northern Hemisphere, as evidenced by the isotope and sediment records of DSDP Site 594. Stratigraphic relationships between loess and marine terraces near Wanganui, provide a framework for linking terrestrial and marine records over the past 500 ka. Plant phytoliths in the loess indicate two major periods of climatically induced deforestation during the last 150 ka, one from 20-50 ka and one from 130-150 ka.

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