To get an overall impression of the general structural setting of a landscape, a remote study of bedrock structures should include studies of the geomorphology at various scales. Thematic maps improve the general understanding of an area. Digital elevation data in 500m, 50m and 10m grids were used for rock-block interpretations at regional, semi-regional and local scales of areas around the two SKB sites, Forsmark in Uppland and Laxemar in Småland, which are objects for SKB’s site-investigation programme. The bedrock head in both areas is interpreted to be close to the surface of the sub-Cambrian peneplain and varying altitude may testify to block-faulting in a distorted peneplain. Topographic breaks and changes in the gradient also reveal possible zones of weakness that may conduct water.
The purpose of the current project is to comprise interpretations made from digital elevation information on areas in the back land of the two site areas. The study is based on the idea that topography gives a clue to structures in the bedrock. Topographic breaks and changes in the gradient could reveal possible zones of weakness that may conduct water. Such changes can be shown on maps as lines and are denoted as lineaments. The distribution of earthquakes could strengthen the interpretation that the delineated pattern of lineaments and rock-block boundaries represent zones of weakness.