Carbonate analysis

We use various types of carbonate - e.g. aragonite from coral, otoliths (fish ear bones), bivalves (sea shells), and speleothems (limestone cave calcite) - in paleoclimate research. Like tree rings, these minerals ‘grow’ in layers that can be dated and their isotopes can be analysed to understand past climatic changes.

NIWA staff worked on a recent Marsden Fund project using geochemical methods to analyse coral, clam shells and otoliths from Aitutaki in the Cook Islands to form a prehistoric climate chronology for the island.

Find out more about the Aitutaki archaeology and climate work