A pollen-analysis was made of the Linder Bruch, which is located on the Lower Rhine Terrace south of Wahn. Additionally, an examination was made of the macro-floral remains. The results show that the organic sediments were deposited at the beginning of pollenzone X/XI (Overbeck & Schneider). They are not old river deposits, but the product of secondary mooring of a dried-up river arm, which apparently belongs to the Rhine system. The overflow-water was run-off from the higher lying Middle Terrace. At present the problem of the varying water-levels in the Linder Bruch remains unresolved. A possibility is the change from forest- to settlement-areas on the Middle Terrace. Why the Linder Bruch did not become moored at a much earlier period has not yet been satisfactorily explained. It is possible that the Merheimer Bruch near Köln results from a secondary mooring, too. Similar to the Linder Bruch it is situated in an old river-channel on the Lower Terrace of the eastern Rhine side.