CHAPTER TWELVE DEEP-SEA CORALS: NEW INSIGHTS TO PALEOCEANOGRAPHY

Abstract

This chapter focuses on the deep-sea corals. Deep-Sea corals provide a widespread archive of oceanographic processes, with annual- to decadal-resolution records spanning several centuries in length. They are ideally suited to the study of rapid changes, such as that which characterized the Pleistocene–Holocene transition. Deep-sea scleractinians exhibit a wide variety of growth forms, from simple, solitary cup corals to complex, branching colonies. The corallite is lengthened by periodic uplift of the polyp and formation of a new dissepiment. The wall of the corallite is called the theca. A series of thin vertical sheets, the septa, radiate from the theca into the center of the corallite. The key utility of corals in paleoceanography is that long records of ambient conditions are locked into the growing skeleton in successive layers. When dealing with tropical reef scleractinians, massive colonies are selected for climate reconstructions because of the simplicity of their growth banding. Deep-sea scleractinians have more complicated cup and branching morphologies, making it difficult to visualize and sample the growth layers. The chapter discusses the growth and sclerochronology in deep-sea scleractinians, growth and sclerochronology in horny corals, sources of carbon to deep-sea corals, and stable isotopic disequilibria in deep-sea corals.