The Second Salpausselkä at Karkkila, southern Finland

This paper describes the results of glacial geological field investigations carried out in 1974 in the 10 km wide zone of the Second Salpausselkä in the area between Karkkila and Loppi in southern Finland. The 2nd Salpausselkä runs in three main parallel belts, each of them forming one or several broken rows of moraine ridges, glaciofluvial deltas of various types, and other transverse formations and deposits. The »transverse eskers» described in some previous papers are interpreted by the present author in the main as gradual forms of glaciofluvial marginal deltas, deposited in general in the sea in front of the ice margin. The typical and flat-topped forms of delta in general grew up to the water level of the ancient Baltic Ice Lake, situated in the study area at 140–150 m above sea level. The sharp-crested primary form of delta did not grow up to water level. The meltwater streams also produced, in addition to separate deltas, radial eskers, often rich in deltas, too. The activity of the ice is shown by the halts or short advances. The 2nd Salpausselkä system was formed in three main stages and the formation lasted about 200 years, 8 500–8 300 B.C