Skip to Main Content
Book Chapter

Earth system transition during the Tonian–Cambrian interval of biological innovation: nutrients, climate, oxygen and the marine organic carbon capacitor

By
Graham A. Shields
Graham A. Shields
Department of Earth Sciences, University College London, Gower Street, London WC1E 6BT, UK
Search for other works by this author on:
Published:
January 01, 2017

Abstract

The Tonian–Cambrian interval (c. 0.9–0.5 Ga) witnessed major tectonic, climatic and chemical changes to the Earth system and culminated in the Ediacaran–Cambrian radiation of animals. Negative carbon isotope (δ13C) excursions of extraordinary magnitude form the backdrop to all these events and are consistent with the presence of a vast marine organic carbon reservoir that changed its size due to periodic imbalances between organic production (as an oxidant source) and terrestrial oxidant sinks. Prior to both Cryogenian glaciations, this pool of long-lived organic carbon may have become substantially depleted, leading to a weakening of the regulation of climate and oxygen. The late Ediacaran Shuram anomaly probably represents a third depletion event, which was followed by oxygenation and the Ediacaran–Cambrian radiation. The evolutionary diversification of animals shortened the ocean residence time of organic carbon and introduced new carbon cycle feedbacks that together helped to mould the modern Earth system.

You do not currently have access to this article.
Don't already have an account? Register

Figures & Tables

Contents

Geological Society

Earth System Evolution and Early Life: A Celebration of the Work of Martin Brasier

A. T. Brasier
A. T. Brasier
University of Aberdeen, UK
Search for other works by this author on:
D. Mcilroy
D. Mcilroy
Memorial University of Newfoundland, Canada
Search for other works by this author on:
N. McLoughlin
N. McLoughlin
Rhodes University, South Africa
Search for other works by this author on:
Geological Society of London
Volume
448
ISBN electronic:
9781786202932
Publication date:
January 01, 2017

GeoRef

References

Related

A comprehensive resource of eBooks for researchers in the Earth Sciences

This Feature Is Available To Subscribers Only

Sign In or Create an Account

This PDF is available to Subscribers Only

View Article Abstract & Purchase Options

For full access to this pdf, sign in to an existing account, or purchase an annual subscription.

Subscribe Now