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Abstract
New Zealand's isolated position in the Southwest Pacific and the quality of its marine and terrestrial sedimentary record make it a valuable source of information for studies of global climate change. A section at Bryce Burn in Southland, South Island, provides a record of middle Miocene global cooling associated with buildup of an extensive semi‐permanent ice sheet on Antarctica. The section yielded δ18O, δ13C, lithological, clay mineral, foraminiferal, and pollen data that have been linked to a high‐resolution age model based on magnetostratigraphy and foraminiferal dating. The sequence exhibits evidence for a δ18O c. 0.6‰ positive baseline shift consistent with the age and magnitude of the E3/ Mi3 isotope excursion around 13.9 Ma, carbon maxima 4–6 δ13C excursions, probable orbitally controlled changes in clay mineralogy, and short‐term changes in terrestrial vegetation. This is the first time these stable isotopic events have been recognised in outcrop sequences in New Zealand. There appears to be no clear, long‐term shift in the data associated with middle Miocene oceanic cooling, apart from the stable isotope evidence, though Milankovitch‐scale, short‐term fluctuations are present.