Several samples from a Tertiary carbonated evaporitic series (Sainte-C
ecile, Camargue, France) were investigated. Their analysis revealed a
high abundance of new or uncommon hydrocarbons and organic S compounds
related to higher plant triterpenes. Several of them, in particular,
12,29-cyclolupa-12,18,20(29)-triene 1, could be positively identified.
These triterpenoids are generally absent from non-evaporitic sediment
s which contain essentially aromatic triterpenoids resulting from micr
obially mediated aromatization processes starting in ring A (or in rin
g B when preceded by the loss of ring A). The uncommon transformations
undergone by higher plant triterpenes in the highly anoxic sediments
from Sainte-Cecile are specific for each series of triterpenes (i.e.,
oleanane, ursane, lupane) and are probably linked with the rapid disap
pearance of the functionality located in ring A by reduction or by the
incorporation of the triterpenes in S-rich macromolecules by reaction
with inorganic S species. These biological markers represent new sour
ce parameters which may be quite useful as indicators of terrestrial i
nputs in evaporitic deposits.