Computer Science
Scientific paper
Mar 2009
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2009e%26psl.279..373t&link_type=abstract
Earth and Planetary Science Letters, Volume 279, Issue 3-4, p. 373-382.
Computer Science
5
Scientific paper
The calcium isotopic composition of porewaters and authigenic carbonates in the anoxic sediments of a convergent continental margin drilled during Ocean Drilling Program (ODP) provides first insight into the different processes that control Ca geochemistry in clastic marine, organic-rich sedimentary environments. In 4 sites drilled during Leg 204 at Hydrate Ridge (Cascadia Margin, offshore Oregon/USA), sulfate is consumed during anaerobic oxidation of methane and of organic matter via sulfate reduction within the upper meters of the sedimentary section. These reactions promote the precipitation of authigenic carbonates through the generation of bicarbonate, which is reflected in a pronounced decrease in calcium concentration. Although Ca isotope fractionation is observed during carbonate precipitation, Ca concentration in the pore fluids from ODP Leg 204 is decoupled from Ca isotopy, which seems to be mainly controlled by the release of light Ca isotopes that completely overprint the carbonate formation effect. Different processes, such as the release of organically bound Ca, ion exchange and ion pair formation may be responsible for the released light Ca. Deeper within the sedimentary section, additional processes such as ash alteration influence the Ca isotopic composition of the porewater. Two sites, drilled into the deeper core of the accretionary prism, reveal the nature of fluids which have reacted with the oceanic basement. These deep fluids are characterized by relatively high Ca concentrations and low δ44/40Ca ratios.
Gussone Nikolaus
Teichert Barbara M. A.
Torres Marta E.
No associations
LandOfFree
Controls on calcium isotope fractionation in sedimentary porewaters does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Controls on calcium isotope fractionation in sedimentary porewaters, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Controls on calcium isotope fractionation in sedimentary porewaters will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-973807