Role of Charcoal Analysis for Interpreting Vegetation Change and Paleoclimate in the Miocene Rhine Embayment (Germany)

Abstract

The potential of fossil wood and charcoal from browncoal deposits as sources of reliable paleoenvironmental information is explored with material from the Lower Rhine Embayment (Germany). The presence of charcoalified material demonstrates proof of natural wildfires in Tertiary mire environments, most probably during, or after periods of increased drainage and drying of surface vegetation and litter. The results presented suggest that sampling from charcoal layers may provide a more statistically reliable data set for study of such environments. Inclusion of taxa recovered from charcoal layers might compensate for the taphonomic and preservational bias of Tertiary lignitic floras based solely on the collection of lignitic wood. These data confirm the hypothesis that, during certain intervals of the Miocene, both monocotyledonous and dicotyledonous angiosperms might have dominated or represented significant portions of the peat-forming vegetation. The importance of palms and shrubby woody taxa, such as ‘Cyrilla’, is particularly striking from new evidence of charcoalified remains. In addition, certain wood anatomical features observed from well preserved lignitic wood and charcoal may be used as indicators of environmentally modulated growth: (1) clear growth rings testify to the existence of a seasonal climate; (2) wide variations in growth ring characters indicate variable environmental conditions; and (3) high incidence of dicotyledonous taxa, with abundant small vessels and scalariform perforation plates, is interpreted as evidence of a mesic environment.