Contact metamorphism around the Innset massif

Different primary chemical compositions of the metasediments on either side of the Innset massif possibly explains the development of different mineral assemblages in the contact zones south-east and north-west of the intrusion. Near the south-eastern contact, a zone of spotted (cordierite-andalusite) argillites has developed outside the inner contact zone of equigranular hornfelses. The temperature distribution around the intrusion is discussed in order to explain textural differences between the inner zone of equigranular hornfelses and the outer zone of spotted argillites. The extents of the contact zones and the minerals present are in agreement with the calculated temperature distribution around the intrusion. The age of the Innset massif and the surrounding contact aureoles is discussed in relation to the major deformation episodes and the regional metamorphism of the area.