Oxygen came late to ocean depths during Paleozoic

09.03.25 | University of Utah

Ancient marine shales deposited 400 million years are exposed in cliffs cut by the Peel River in Canada’s Yukon. Isotope analysis on the thallium contained in these deposits helped reconstruct deep-ocean oxygen levels 485 to 380 million years ago. Credit: Erik Sperling, Stanford University

Thallium isotopes show O2 levels rose and fell at the ocean floor long after marine animals appeared and diversified half billion years ago, according to study of ancient marine sediments exposed by river cuts in Canada's Yukon

Science Advances

10.1126/sciadv.adw5878

Observational study

Not applicable

Dynamic deep marine oxygenation during the early and middle Paleozoic

3-Sep-2025

The authors declare they have no competing interest.

Additional Media

A group of geologists that includes co-authors Justin Strauss and Tiffani Fraser examine Silurian strata of the Tetlit Formation exposed on the Peel River, Yukon Territory in 2015. Credit: Erik Sperling, Stanford University

Article Information

Journal

Science Advances

DOI

10.1126/sciadv.adw5878

Method of Research

Observational study

Subject of Research

Not applicable

Article Publication Date

2025-09-03

Article Title

Dynamic deep marine oxygenation during the early and middle Paleozoic

COI Statement

The authors declare they have no competing interest.

Contact Information

Brian Maffly

University of Utah

brian.maffly@utah.edu

Source

This article is based on a news release from University of Utah. BrightSurf curates and republishes science news from research institutions worldwide; the original release is linked below.

Original Source

https://attheu.utah.edu/?p=116047&preview=true

How to Cite This Article