Dear Bill, Perhaps this will be helpful. In the last 7000 years profile, the d13C value of organic matter in Gotland sediments vary from to -28.9 to –25.9 ‰. The d13C and d18OPDB values in carbonate (rhodochrosite) in the same sediments vary from -8.4 to –6.5 ‰ and from –3.4 to –1.1 ‰, respectively. If you need - more data you can find at: Jedrysek M.O., Skrzypek G., Halas S., Kral T., Pazdur A., Wada E., Takai Y., Vijarnsorn P., Doroszko B., Kaluzny A., Weber-Weller A., and Wójcik A., 1999, Seawater/freshwater records in stable isotope composition of sediments: marine muds from Baltic’s Gotland deep and mangrove peat profile from Thailand., Quaternary Studies in Poland., Special Issue-1999, 127-133. Mariusz ___________________________________ "William P. Patterson" wrote: > Dear Isogeochemists, > I'm currently collaborating on a project investigating the life history of > Iron age Cod from the Baltic Sea (Gotland). Water temperatures calculated > from d18O values of cod otoliths (using modern cod thermal tolerance) > suggest a rather low d18O value for the Baltic Sea during the Iron age > (-5”VSMOW). > > Two questions.... > Has anyone attempted to calculate the Baltic Sea water values for the Iron > age? > Are there any studies which have determined the isotope value of the modern > Baltic Sea (DIC and/or d18O)? > > Thanks, > Bill > > William P. Patterson > Syracuse University > Department of Earth Sciences > Syracuse, NY 13244-1070 > > Phone: 315-443-3869 > FAX: 315-443-3363 > URL: http://128.230.24.91/bill.html