Till studies in the Gudbrandsdal area, eastern central Norway

Abstract

A number of localities with sub-till sediments have recently been found in the Gudbrandsdal area. The sediments are mostly of glacio-lacustrine origin and of an assumed Middle Weichselian age. Only a few of the findings have been described hitherto (Bergersen and Garnes, 1971). The author has succeeded in establishing a preliminary stratigraphy in the overlying, often thick, till deposits. The different tills are correlated to four ice-movement phases. The lower till shows certain characteristics textures, and has re-transported sediments incorporated. This till often has the surface morphology of a terrace or of a stoss-side moraine. These tills are assumed to have been deposited from valley glaciers during the initial stage of the last glaciation (phase A). The most widespread and thickest tills in the area are correlated to the succeeding, predominant, inland-ice stage (phase B). During this stage, the ice had a movement more or less obliquely to the side valleys, and the tills were very often deposited as lee-side moraines. From the later inland-ice stage, phase C, as well as from the deglaciation period, phase D, there are relatively few glacial deposits in the investigated area. This is presumably due to the fact that the area was situated in the reconstructed ice culmination zone during these phases.