Lorrey, A., Williams, P., Salinger, J., Martin, T., Palmer, J., Fowler, A., Zhao, J.-X. and Neil, H. 2008. Speleothem stable isotope records interpreted within a multi-proxy framework and implications for New Zealand palaeoclimate reconstruction. Quaternary International 187: 52-75.
A master speleothem δ18O record (which is a proxy for temperature) was developed for New Zealand's eastern North Island for the period 2000 BC to about AD 1660 from data acquired from three speleothems of Disbelief and Te Reinga caves. This record revealed that the warmest time interval of the nearly 4000 years occurred between about AD 900 and 1100. Because the record did not extend beyond AD 1660, however, we cannot compare peak MWP warmth with peak CWP warmth.