Selenium Isotope Paleobiogeochemistry

This Element considers selenium isotopes as a paleoenvironmental tracers and what we can learn from isotopic fractionations.

Eva E. Stüeken (Author), Michael A. Kipp (Author)

9781108749169, Cambridge University Press

Paperback / softback, published 8 October 2020

75 pages
15 x 23 x 0.2 cm, 0.6 kg

The attraction of selenium isotopes as a paleoenvironmental tracer lies in the high redox potential of selenium oxyanions (SeIV and SeVI), the dominant species in the modern ocean. The largest isotopic fractionations occur during oxyanion reduction, which makes selenium isotopes a sensitive proxy for the redox evolution of our planet. As a case study we review existing data from the Neoarchean and Paleoproterozoic, which show that significant isotopic fractionations are absent until 2.5 Ga, and prolonged isotopic deviations only appear around 2.3 Ga. Selenium isotopes have thus begun to reveal complex spatiotemporal redox patterns not reflected in other proxies.

1. Introduction
2. Materials and Analytical Methods
3. Proxy Mechanics
4. Case Study
5. Future Prospects.

Subject Areas: Climate change [RNPG], Palaeontology [RBX], Oceanography [seas RBKC], Geochemistry [RBGK], Biochemistry [PSB]