Hay Hay,

I'm Jens and I'm new in the Isogechem list and of course I have a question.
I'm working on carbonat preciptates induced by gashydrate decomposition
in the accretionary prism of Oregon (for my PhD). I found high-MgCc
together with
aragonite cementing the sediment. To see the influence of the hydrate water I
corrected the 18O data of MgCc for the Mg-content (Tarutani)
but I can't use the factor 0.6 for Aragonite, because the temperature in 780m
waterdepth was 4°C (and not 25°C).
What I'm looking for now is a equation for the fractionation of 18O which
depends on the
temperature and the d18O of the source water. I know the equation from
Grossman and Ku (1981),
but I can't believe that the fractionation for benthic foraminifers and for
anorganic aragonite precipitaion is the same.

So, is there anybody in the world who can tell me how anorganic aragonit
fractionates oxygen isotopes.

Cheers                         JENS

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 Jens Greinert
 GEOMAR
 Forschungszentrum fuer marine Geowissenschaften
 Abt. Marine Umweltgeologie
 Wischhofstr. 1-3
 24148 Kiel, Germany

 phone: ++49 431 600 2114
 fax:   ++49 431 600 2928
 email: [log in to unmask]
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