Dear Melanie,

The only reference I have for reservoir corrections around the Galapagos
gives values for Delta R which average 20 +/- 25 (Taylor and Berger,
1967) or 5 +/-15 for the eastern equatorial Pacific (compiled in Stuiver
et al., 1986).  If you find any more recent measurements I would
appreciate learning about them.

Good luck!
Paula

Stuiver, M., Pearson, G.W., and Braziunas, T.F., 1986, Radiocarbon age
calibration of marine samples back to 9000 cal yr BP, Radiocarbon
28:980-1021.

Taylor, R.E., and Berger, R., 1967, Radiocarbon content of marine shells
from the Pacific coasts of Central and South America, Science
158:1180-1182.


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On Mon, 19 Jan 1998, Melanie A. Riedinger wrote:

> Hi,
> I am looking for some advice (people to contact or refs) regarding
> the reservoir effect in the Southern Hemisphere.
>
> We are  working on a core from a hypersaline crater lake in the Galapagos
> Islands. The lake is coastal, and likely receives ocean spray quite
> frequently, and may be hit by ocean waves during storm events (though
> we have some fossil evidence which suggests this may be minor - no marine
> diatoms in the core).
> The delta 13C values for our dates are positive - -9.99 to -18.29.
> (Methanogenic activity is quite likely at ths site).
>
> The youngest date for the core is 416 +/- 60 BP (AMS) at 11 cm.
> (The next is 755 +/- 30 BP, at 28.5 cm). (Incidentally, we tried Pb dating
> a short core from this site, and got no measurable Pb).
>
> We have 19 dates so far, most AMS, and all but a few are in
> chronological sequence (over a > 4 m core).
>
> I know that there are many things that can influence dates in this area:
> - the 30 yr increase over northern hemisphere dates because of greater CO2
> exchange due to large ocean surface area in southern hemisphere
> - small C content from samples from islands
> - fossil carbon release in volcanic regions
> - upwelling of deep water in coastal areas
>
> 1. Could someone point me to a ref (or person) re: the ocean reservoir
> correction in the equatorial pacific (eastern)?
> 2. Does anyone know of "other types" of reservoir effects we should be
> concerned about (not listed above)?
>
>
> Thanks in advance for your suggestions!
>
> Best, Melanie Riedinger
> *******************************************************************************
> Melanie Riedinger                       5500 N. St. Louis Avenue
> Assistant Professor                     Chicago, Illinois 60625-4699
> Department of Biological                Phone: 773-794-2631
>   & Exercise Sciences                   FAX: 773-794-2924
> Northeastern Illinois University        E-mail: [log in to unmask]
>