Organic Geochemical Proxies

Meyers, P.A. (1997) Organic geochemical proxies of paleoceanographic, paleolimnologic, and paleoclimatic processes. Org. Geochem. 27, 213-250. 

Anoxia was certainly a characteristic of the Late Devonian, but in the western US, based on geochemical proxies, anoxia ended 6 m below ( 100kyr before) the major F-F extinction. Bratton et al. (1999) discuss the possibility that this was a local phenomenon and that anoxia persisted through the F-F boundary elsewhere, but favor the alternative hypothesis that other sections suffered depositional hiatus or erosion of the latest Frasnian sediments. A positive excursion (in both carbonate and organic carbon) began in the Frasnian but continued well into the Famennian (Wang et al., 1996). A positive pyrite sulfur isotope excursion also occurred at this time. If these excursions indicate enhanced organic carbon and pyrite sulfur burial under widespread anoxic conditions, then it would seem that such conditions persisted well beyond the F-F boundary extinction. 

Huguet, C., Smittenberg, R.H., Boer, W Sinninghe Damste, (.S., and Schouten, S. (2007) Twentieth century proxy records of temperature and soil organic matter input in the Drammmensf)ord, southern Norway. Org. Geochem., 38,1838-1849. 

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