Constraining past environmental changes of cold-water coral mounds with geochemical proxies in corals and foraminifera

Abstract

Cold-water coral (CWC) reefs and mounds are and have been biodiversity hotspots of the deep sea. As their occurrence depends on specific environmental parameters, gaining hindsight on changing ocean conditions under on-going climate change is the key to a better understanding of CWC mound development through time. A convenient technique for reconstructing the palaeoenvironment during periods of CWC mound growth is by extracting geochemical proxies from biologically mediated carbonates. Here, the focus is on probably the two most abundant calcareous archives, that are, cold-water Scleractinia and Foraminifera, with an overview of the geochemical proxies (selection) used in these aragonitic and calcitic skeletons from CWC mounds. A particular emphasis is set on constraining proxies for temperature, salinity, seawater density, seawater carbonate systems parameters (pH, CO32−), nutrients, oxygen and water mass tracers.