Chromium Isotope System as a Tracer of Ocean and Atmosphere Redox

The stable chromium (Cr) isotope system is a powerful tool for tracking changes in the amount of oxygen in Earth's ocean-atmosphere system, providing novel insights into Cr redox cycling and probing the earth's long-term atmospheric oxygenation.

Format: Paperback / softback
Length: 75 pages
Publication date: 25 February 2021
Publisher: Cambridge University Press

The stable chromium (Cr) isotope system has emerged as a groundbreaking tool in the past decade to track changes in the amount of oxygen in Earth's ocean-atmosphere system. Initially, the use of Cr isotopes (δ53Cr) as a paleoredox proxy required significant revision, but the fundamental concept behind their utilization as redox tracers remains straightforward. The largest isotope fractionations occur during partial reduction of Cr(VI), making Cr isotopic signatures invaluable in understanding Cr redox cycling in both marine and terrestrial environments.

Crucially, the Cr isotope system stands out from many other trace metal proxies in its ability to respond to short-term redox perturbations. This responsiveness is particularly important when studying phenomena such as Pleistocene glacial-interglacial cycles, where rapid changes in oxygen levels occur. By analyzing the Cr isotopic signatures, researchers can gain insights into these dynamic redox processes and better understand the Earth's climate history.

Furthermore, the Cr isotope system provides a unique perspective on Earth's long-term atmospheric oxygenation. While the levels of oxygen have fluctuated throughout Earth's history, the Cr isotopic signatures suggest that, for the majority of time, oxygen levels have been relatively low but likely dynamic. This information sheds light on the complex interplay between oxygen production, consumption, and atmospheric circulation and helps us better understand the conditions that have shaped the Earth's ecosystems over millions of years.

In conclusion, the stable chromium (Cr) isotope system has revolutionized our understanding of oxygen dynamics in Earth's ocean-atmosphere system. Its ability to respond to short-term redox perturbations, coupled with its insights into long-term atmospheric oxygenation, has opened up new avenues for research in environmental science and climate history. As scientists continue to refine and expand their use of Cr isotopes, we can expect to gain a deeper understanding of the complex processes that govern our planet's ecosystems and the role of oxygen in shaping our world.

Weight: 68g
Dimension: 151 x 230 x 7 (mm)
ISBN-13: 9781108792578