Surficial sediment composition as a record of environmental changes in thecatchment of shallow Lake Petersdorf, Brandenburg, Germany

A chemical characterization of the surficial sediment (0-20 cm) of type 'dy ' (org-C-part/TNpart> 10) of the anthropogenically polluted shallow Lake Pe tersdorf is presented. Eighty samples were analyzed for a set of parameters , i.e. dry weight, loss on ignition (LOI), total inorganic carbon (TIC), N, S, P, Ca, Si, As, Fe, Al, Mn, Zn, Cd, and Pb. LOI, TIC, N, S, Ca, P, and Z n tend to accumulate at a water depth > 2 m (70.6% of the lake surface) in contrast to Mn and Fe which are more widely distributed, and Cd and Pb whic h are accumulated in the lake part close to a road. The enrichment factors of certain elements, e.g. Al (23.9%), Si (31.5%), P (12.2%), and Ca (68.7%) from 20 cm sediment depth up to the surface, are attributed to incisive ch anges in the immediate catchment. Erosion, fertilization, amelioration, and separation of the peatland north of the lake by a dam within the last 60 y rs resulted in the change of Lake Petersdorf from a dystrophic to a eutroph ic stage. This enhanced the mineralization of its meso-humic (LOI/TNpart=20 .6) sediment.