Hi Alayne,

to my knowledge there are at least two publications of Schidlowsik et al. that 
deal with heavy carbon isotope ratios of sedimentary organic matter.

Schidlowski, M., Matzigkeit, U., and Krumbein, W.E. (1984): Super-heavy carbon 
from hypersaline microbial mats. Naturwissenschaften, 71, 303-308.

Schidlowski, M., Matzigkeit, U., Mook, W.G., and Krumbein, W.E. (1985): Carbon 
isotope geochemistry and 14C ages of microbial mats from the Gavish Sabkha and 
the Solar Lake. Friedman, G.M., and Krumbein, W.E. (eds.): Hypersaline 
Ecosystems: the Gavish Sabkha (Ecol. Stud., 53), 381-401, Springer, Berlin.

Regards, Uli

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Ulrich Berner
Stable Isotope Lab
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