Author
Listed:
- François Robert
(Muséum National d'Histoire Naturelle, Centre National de la Recherche Scientifique Laboratoire d'Etude de la Matière Extraterrestre Nanoanalyses, UMS 2679)
- Marc Chaussidon
(†Centre de Recherches Pétrographiques et Géochimiques, Centre National de la Recherche Scientifique, BP20)
Abstract
Robert & Chaussidon The possibility of a change in δ18O values of the oceans has been discussed for the past 30 years1 and the comment by Shields and Kasting2 does not really bring any new insight into this issue. The carbonate δ18O curve3 is indistinguishable from that of cherts and shows a huge scatter caused by local geological processes. This scatter in δ18O (up to 20‰ at a given age) far exceeds the sensitivity of the isotope thermometer (about 2‰ per 10 °C). It therefore prevents any precise additional test of the model and no consensus was ever reached in the literature on this debate from oxygen-isotope data alone. Our approach4, by contrast, was to try to find another isotopic proxy (δ30Si) that could bring new and independent constraints to test the hypothesis of hot oceans in the early Precambrian. Our interpretation of the δ30Si values in terms of temperature is fully coherent not only with the δ18O of cherts but also with that of marine carbonates, and certainly does not overlook these data. In addition, we indicated4 that our sample set has not the time resolution that would be necessary to look for an effect on silicon isotopes of Precambrian global glaciations. No chert samples from such periods were analysed.
Suggested Citation
François Robert & Marc Chaussidon, 2007.
"Evidence for hot early oceans? (Reply),"
Nature, Nature, vol. 447(7140), pages 1-2, May.
Handle:
RePEc:nat:nature:v:447:y:2007:i:7140:d:10.1038_nature05831
DOI: 10.1038/nature05831
Download full text from publisher
As the access to this document is restricted, you may want to search for a different version of it.
Corrections
All material on this site has been provided by the respective publishers and authors. You can help correct errors and omissions. When requesting a correction, please mention this item's handle: RePEc:nat:nature:v:447:y:2007:i:7140:d:10.1038_nature05831. See general information about how to correct material in RePEc.
If you have authored this item and are not yet registered with RePEc, we encourage you to do it here. This allows to link your profile to this item. It also allows you to accept potential citations to this item that we are uncertain about.
We have no bibliographic references for this item. You can help adding them by using this form .
If you know of missing items citing this one, you can help us creating those links by adding the relevant references in the same way as above, for each refering item. If you are a registered author of this item, you may also want to check the "citations" tab in your RePEc Author Service profile, as there may be some citations waiting for confirmation.
For technical questions regarding this item, or to correct its authors, title, abstract, bibliographic or download information, contact: Sonal Shukla or Springer Nature Abstracting and Indexing (email available below). General contact details of provider: http://www.nature.com .
Please note that corrections may take a couple of weeks to filter through
the various RePEc services.