The University of Southampton
University of Southampton Institutional Repository

Comment on “What do we know about the evolution of Mg to Ca ratios in seawater?” by Wally Broecker and Jimin Yu

Coggon, Rosalind M., Teagle, Damon A.H. and Dunkley Jones, Tom (2011) Comment on “What do we know about the evolution of Mg to Ca ratios in seawater?” by Wally Broecker and Jimin Yu Paleoceanography, 26, (3), PA3224. (doi:10.1029/2011PA002186).

Record type: Article


A record of the Mg/Ca ratio of ancient seawater is essential to understand variations in the major geological processes that control ocean chemistry and for estimating past ocean temperatures. A recent contribution by Broecker and Yu (2011) regarding past seawater Mg/Ca provides an unbalanced assessment of the uncertainties and key assumptions of the methodologies considered. It misrepresents aspects of a new method to estimate past ocean Mg/Ca proposed by Coggon et al. (2010); here we provide clarification of that approach. We estimate the accuracy and precision of seawater Mg/Ca estimates derived from planktonic foraminifera test calcite, the preferred approach of Broecker and Yu. These are shown to be consistent with other records that suggest major changes in seawater cation chemistry. An explanation of how major changes in the Mg/Ca of seawater might occur is beyond the scope of this comment.

Full text not available from this repository.

More information

Published date: 2011
Organisations: Ocean and Earth Science, Geochemistry


Local EPrints ID: 201075
ISSN: 0883-8305
PURE UUID: 364b3623-43a8-4f28-84d1-0765e4efa84b
ORCID for Damon A.H. Teagle: ORCID iD

Catalogue record

Date deposited: 25 Oct 2011 09:40
Last modified: 18 Jul 2017 11:13

Export record



Author: Tom Dunkley Jones

University divisions

Download statistics

Downloads from ePrints over the past year. Other digital versions may also be available to download e.g. from the publisher's website.

View more statistics

Atom RSS 1.0 RSS 2.0

Contact ePrints Soton:

ePrints Soton supports OAI 2.0 with a base URL of

This repository has been built using EPrints software, developed at the University of Southampton, but available to everyone to use.

We use cookies to ensure that we give you the best experience on our website. If you continue without changing your settings, we will assume that you are happy to receive cookies on the University of Southampton website.