At Os, near Bergen, western Norway, there occur several gullies in glaciomarine silt. The gullies, up to 450 m long and 7 m deep, lead into the lake B anktjørn, where the eroded sediments were deposited. The analyses of several cores from the lake sediments allowed the gully sediments to be identified and dated as having been formed in the period from 8,800 to 7,700 years B. P. Denudation rates for this period have been estimated at 1 .45 mm/year in the silt covered area. The dating was based on pollen diagrams and 14C dates. The Holocene history of the vegetation, redeposition of pollen, and lateral variation of the pollen content in lacustrine sediments are also discussed.