The western limit of the Glacial marl in the district of Lake Mälaren, Central Sweden. The map (Fig. 1) shows all observations of lime content in Glacial clay around Lake Mälaren. The marl forms characteristic lobes which are quite independent of the topography. Accordingly there has been a strong current westwards in front of the ice. This has probably caused an opposite current of brine, which may explain the irregular varves of the clay in the district.