The Blue Road Geotraverse: The Bouguer field and optimized density models

Abstract

On the basis of national gravity surveys in Sweden and Norway and additional gravity measurements within a zone ∼50 km wide along the Blue Road Geotraverse, a Bouguer map was produced for the geotraverse area. In order to explain the large, negative, Bouguer anomaly within the mountain area, two-dimensional density models limited by polygons were used, and the geometrical parameters optimized by a least-squares procedure. Mass deficiencies from relicts of a downgoing slab during the Caledonian orogeny seem to be unlikely from the isostatic point of view. Mass deficiencies caused by a depression of the Moho seem reasonable when isostacy is considered. Clear seismic evidence, however, is still lacking.