Quick
Search: 		  
advanced search
 GSW Home   GeoRef Home   My GSW Alerts   Contact GSW   About GSW   Journals List   Help 
European Journal of Mineralogy Email Content Delivery
JOURNAL HOME HELP FEEDBACK/COMMNET SUBSCRIBE ARCHIVE SEARCH TABLE OF CONTENTS
European Journal of Mineralogy; April 2008; v. 20; no. 2; p. 173-181; DOI: 10.1127/0935-1221/2008/0020-1803
© 2008 E. Schweizerbart'sche Verlagsbuchhandlung Science Publishers
This Article
Right arrow Figures Only
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Right arrow Citation Map
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Google Scholar
Right arrow Articles by Ribeiro Da Costa, I.
Right arrow Articles by Taylor, R. N.
GeoRef
Right arrow GeoRef Citation

Articles

Late seafloor carbonate precipitation in serpentinites from the Rainbow and Saldanha sites (Mid-Atlantic Ridge)

Isabel Ribeiro Da Costa1,*, Fernando J.A.S. Barriga1 and Rex N. Taylor2

1 CREMINER-LA/ISR and Departamento de Geologia, Faculdade de Ciências da Universidade de Lisboa, Edifício C6-Piso 4, Campo Grande, 1749-016 Lisboa, Portugal
2 School of Ocean and Earth Sciences, Southampton Oceanographic Centre, Empress Dock, SO14 Southampton, United Kingdom

* Corresponding author, e-mail: isabelrc{at}fc.ul.pt

Serpentinized ultramafic rocks recovered during several recent oceanographic missions (1997–2002) on the Rainbow hydrothermal field and on the Saldanha seamount (36°14'N and 36°34'N, Mid-Atlantic Ridge) often exhibit late-stage carbonatization associated to secondary oxidation effects. These carbonate occurrences, mostly vein-filling aragonite, occasionally form dense webs almost completely engulfing and replacing the serpentinite itself.

The 87Sr/86Sr (approx. 0.709) and stable isotope signatures ({delta}13CPDB = 0.2–3.3 {per thousand}; {delta}18OV–SMOW = 32.2–35.2 {per thousand}) of the carbonate fraction in these serpentinites indicate carbonate precipitation from unmodified seawater, under abiotic conditions, and very low temperatures, close to bottom-water temperatures measured at the sampling stations. These analytical data imply that, unlike the serpentinite-hosted carbonate chimneys in the Lost City hydrothermal field (Ludwig et al., 2006), the vein-filling aragonite in the Rainbow and Saldanha serpentinites has a non-hydrothermal, low-temperature seawater origin.

Key-words: low-T carbonates, aragonite, serpentinites, Mid-Atlantic Ridge.






JOURNAL HOME HELP FEEDBACK/COMMNET SUBSCRIBE ARCHIVE SEARCH TABLE OF CONTENTS
Copyright © 2008 by E. Schweizerbart'sche Verlagsbuchhandlung Science Publishers