More on Dating

In the last few decades, most of the geochemical studies on cold-water corals have focused on two research areas.

The first area focuses on dating the absolute age of the coral skeletons using 230Thorium/Uranium (Th/U) and/or 14C, and using coupled 230Th/U-14C dating to reconstruct past ocean ventilation.

To do this, we can use sediment cores from coral mounds/reefs, which are cylindrical sections of sediment extracted using special underwater drills. These sediment cores allows us to see favourable periods for coral growth and mounds/reefs expansion in that one location. In other words, where there is a lot of coral growth, we know environmental conditions were favourable, and where there is no coral growth then conditions weren’t favourable (assuming that in the past, corals ‘favourable’ conditions were the same as today). 

The second group of studies aims to gain a better understanding of the processes affecting the chemistry of cold-water coral skeletons and to establish new calibrations for using cold-water corals as palaeo-proxies, such as looking at the role of temperature in the biomineralisation processes.