SESQUITERPENOID AND DITERPENOID BIOMARKERS PRESERVED IN TAXODIUM-RICHOLIGOCENE OXBOW LAKE CLAYS, WEISSELSTER BASIN, GERMANY

Several diterpenoids of the abietane, pimarane and phyllocladane type, and three cadalane-type sesquiterpenoids have been identified in the organic solvent extracts of Lower Oligocene clay sediments (Haselbach strata, Saxony, Germany). The sediment contains needles and cone scale s of a fossil Taxodium species which represents the only conifer in th e samples. A clear correlation between the observed conifer biomarkers and Taxodium is evident. Apart from diterpenoids detected previously in other sediments, a new diaromatic totarane diterpenoid is reported. In isolated fossil and Recent Ta?codium needles and cone scales as we ll as in the Haselbach clays a phenolic diterpenoid of the abietane-ty pe, ferruginol, has been identified. The results indicate that the Tax odium-rich clay samples contain several diterpenoids which so far have been used as biomarkers for other conifer families and thus the chemo taxonomical use of diterpenoid biomarkers for the differentiation of f ossil conifer families has to be revised. (C) 1997 Elsevier Science Lt d.