BREBEVEGELSE

The superficial deposits occuring within the map-area are described and classified according to their genesis. In the mountains a discontinuous or thin cover of till dominates with peat in the depressions. In the lowland areas glaciomarine sediments were deposited at a sea-level situated c. 180 m above the present one. In Frosta and Skatval these sediments are overlain by till, deposited by a glacial advance during early Younger Dryas, reaching just to the west of the map-area. Marginal moraines from a late Younger Dryas glacial advance can be traced more or less continuously from Hegra in Stjørdal toowards Hoklingen and Alstahaug. During the shoreline displacement the sediments below the upper marine limit were influenced by fluvial erosion and slides. Short accounts are given on the potential for different utilization of the mapped superficial deposits.

The superficial deposits occurring within the map-area are described and classified according to their genesis. In the mountains till and organic deposits dominate. In the lowland areas glaciofluvial and glaciomarine sediments were deposited at a sea-level situated c. 180 m above the present one. During the shoreline displacement these sediments were strongly influenced by fluvial erosion and slides. The ice recession vas interrupted by a glacial advance during the first half of the Younger Dryas glacial advance ca be traced less continuously from the lakes Store Dragstsjøen - Foldsjøen towards Frigården, Lånke, and Hegra in the Stjørdal valley. Radiocarbon datings from Frosta, Levanger and Verdal indicate that these marginal deposits were formed during late Younger Dryas. Short accounts are given on the potential for different utilization of the superficial deposits.

The superficial deposits occurring within the map-area are described and classified according to their genesis. In the mountains, till and organic deposits dominate. In the lowland areas glaciofluvial and glaciomarine sediments were deposited at a sea-level situated c. 175 m above the present one. During the shoreline displacement these sediments were strongly influenced by fluvial erosion and slides. The ice recession was interrupted by a glacial advance which took place dUring the first half of the Younger Dryas Chronozone, reaching just to the north of the map-area. Another glacial advance can be traced from the southwestern part of the map towards Reinsfjell and possibly to the western part of the lake Selbusjøen. These marginal moraines were deposited during late Younger Dryas. Short accounts are given on the potential for different utilization of the superficial deposits.

The superficial deposits occurring within the area of this map-sheet are classified according to their genesis and described. Based on glacial striae and till stratigraphy 3-4 regional and one (youngest) local icemovement directions are reconstructed. During deglaciation the meltwater was ice-directed. Three phases in the deglaciation are distinguished on the basis of changing meltwater drainage routes.

The superficial deposits within the area of the map-sheet Askvoll, in western Norway are classified and described. Ice movements and the course of deglaciation are reconstructed. The thin and discontinous cover of till and the weathering material are the most extensive deposits in the area. The bogs and the marine deposits are of some economic importance, being used for cultivation. Two glaciation phases are reconstructed on the basis of glacial striae. Ice movement during the older phase was towards the west; this must have been of the pre-Younger Dryas age. The younger phase corresponds well with the Younger Dryas end moraines. Grain-size and lithological analyses have been carried out on the superficial deposits. The tills are dominated by material from the local bedrock, and their predominant grain sizes are those of sand and gravel. Geochemical analyses have also been carried out on superficial deposits.

The superficial deposits occurring within the map-sheet are described and classified according to their genesis. Short accounts are also given on sand and gravel resources and groundwater resources. Ablation till and sandy basal till are the dominant deposits. The till cover is mostly continous and thick. The biggest glaciofluvial and fluvial deposits are situated at the mouths of the main valleys. There are also concentrations of these sorted, sandy and gravelly deposits along the main meltwater drainage routes at Hunder in Gudbrandsdalen, and south of Sjusjøen. A fine-grained bluish grey basal till, named the Jørstad till, dominates at 2 m and more below surface througout the area, but mainly in the valleys. The ice flow direction during the initial part of the last glaciation followed the main valleys.
Subsequently the ice movements were directed to the SE. In the next phase the
ice movement were to the SSE-S and locally to the SSW. During the course of
deglaciation the ice movements gradually turned towards lake Mjøsa both
from the west and from the north. The last local ice movements followed the
main valleys. There are indications of a water level at about 180 m a.s.l.
near Lillehammer and at Vingrom 6 km south of Lillehammer. The water level
in lake Mjøsa at Lillehammer sank below 130 m a.s.l. prior to 8.200 years B.P.

The superficial deposits within the map-sheet Hølonda were formed during the Late Weichselian and Holocene. At the time of deglaciation the sea-level was situated ca. 175 m above the present one, and fine-grained marine sediments were deposited distal to ice-marginal glaciofluvial deposits. In the central part of the map area the superficial deposits are dominated by till and glaciofluvial sediments. In the mountainous areas the till cover is generally thin and discontinous. The ice recession occurred during the Allerød (12 000-11 000 years B.P.), but remnants of glacier may still have remained in the central part of Hølonda during an early Younger Dryas glacier advance, taking place 10 800-10 500 years B.P. Short accounts are given of geological processes during the Late Weichselian and Holocene. The potential for different utilization of the superficial deposits is also briefly discussed.