Chapter Six Planktonic Foraminifera as Tracers of Past Oceanic Environments

Publisher Summary This chapter focuses on the planktonic foraminifera as tracers of past oceanic environments. Paleoceanography has always been closely connected with the study of planktonic foraminifera. The prolific production and excellent preservation of foraminiferal fossils in oceanic sediments has produced probably the best fossil record on Earth, providing unparalleled archives of morphological change, faunal variations, and habitat characteristics. Planktonic foraminifera are the most common source of paleoceanographic proxies, be it through the properties of their fossil assemblages or as a substrate for extraction of geochemical signals. The steady rain of foraminiferal shells is responsible for the deposition of a large portion of deep-sea biogenic carbonate. Stable isotopic signals extracted from planktonic foraminifera soon became a standard tool for the recognition of glacial cycles and eventually facilitated the recognition of orbital pacing of the ice-ages. The chemical composition of foraminiferal calcite proved to be a fertile ground for the development of proxies. The chapter highlights the most common and most promising foraminiferal proxies and puts them in the context of modern biological knowledge.