A review of benthic foraminiferal oxygen and carbon isotopes
Babette Hoogakker, Toyoho Ishimura, Lennart de Nooijer, Anthony E. Rathburn, Gerhard Schmiedl
Abstract
Stable isotopes in the calcium carbonate of benthic foraminifera provide important paleoenvironmental information about seawater/sedimentary porewaters that these foraminifera live in. Oxygen isotopes provide essential insights about variations in deep water temperatures and sea-level/ice volume changes, while carbon isotopes provide information about sea-water carbon/nutrient cycling. In this review we look into detail at the direct and indirect mechanisms that contribute to stable oxygen and carbon isotope signals in Rotaliid benthic foraminifera. This includes effects from ontogenetic- and calcification mechanisms, and the impact of methane seeps and post-depositional diagenesis. We conclude our review with an overview of current challenges and provide recommendations for future research endeavors aimed at outstanding knowledge gaps in understanding how these biomineralizers control their stable isotopes. • Benthic foraminifera oxygen and carbon isotopes are influenced by multiple factors. • This includes environmental conditions, but also mobility, ontogeny and calcification mechanisms. • Future directions are discussed that can address current issues and challenges.