A multidisciplinary research into the Caledonian structural development of the Oslo basin, with focus on the calcite veins of the Fornebu and Bygdøy sections

Abstract

Field data shows deformation style matching the structural model of (Bruton et al. 2010), but there is a contrasting deformation style between the two section. The Fornebu section is marked by large scale folds, and a major fault, while the Bygdøy section is best described as a foldtrain, with smaller scale folds. This contrasting style can be best explained trough a higher Fluid pressure at Fornebu compared to Bygdøy, creating more (layer parallel) veins. These layer parallel veins act as slip surfaces, which combined with a higher id pressure allow for the easier formation of larger scale folds. Other factors that might have played a role are lithlogical differences and structural level. The analogue modeling results show that layer-parallel slip and lithlogical differences indeed play an important role in controlling deformation style and in general support the multiple structural level hypothesis as proposed by (Bruton et al. 2010).