Some Experiences of Mapping Surficial Deposits in 
Northern Sweden by means of Air Photo Interpretation 
By Erik Bergström 
Investigation of the surficial deposits on the basis of photo interpre- 
tation has been used only on a small scale in Sweden up to this date. In 
the Swedish State Power Board, however, it has been practised for 
some years in northern Sweden, both for searching for special soils, 
i. e. such suitable for concrete aggregate and impervious sill and the 
purpose of mapping the surficial deposits. Some examples and experi- 
ences from this will be presented here.!) 
In an area of about 2 000 square kilometres in southern Lappland, 
where several water power plants and dams were proposed, there was 
a strong need of concrete aggregate. By means of air photo inter- 
pretation, which was limited to ten km wide zones along each road in 
the area, about fifty deposits of glacifluvial material were found, which 
were then investigated for their quantity and quality. While all of them 
contained enough material, only four, however, had the right quality. 
Of the rest many had too high a percentage of quickweathering schisty 
material. 
À total area of about 6 000 km? has so far been mapped by air photo 
interpretation most of it in areas without roads and so rather inaccess- 
ible. Fig. 1. This interpretation was based on many different facts, 
such as dimensions and morphology, situation and pattern, texture and 
photographic tone, shadows and "wounds". Very important is the gene- 
ral view of an area which the air photos may give and which then 
makes the identification and mapping much easier. Of course, it is 
necessary that the interpreter posesses a good knowledge of the geology 
of surficial deposits and gemorphology in general and that he has made 
field studies in areas of similar character as the one of interest. 
Rock outcrops are common in high areas; on the crests and peaks of 
hills and mountains etc. They also occur frequently, where meltwater 
streams from the receding inland-ice have been active, 1. e. both in 
well-developed meltwater channels and over wider areas. When the out- 
  
1) The mapping was started on the initiative of Mine engineer A. Nordstróm. 
Beside the author Professor G. Hoppe and L. Vilborg, F. M., Department of 
Geography, University of Stockholm have taken part in the project. 
2