The Eidsfjord anorthosite, Vesterålen, Norway: field observations and geochemical data.

Abstract

New fieldwork in the Eidsfjord anorthosite on Langøy, Vesterålen, Nordland, has revealed that the anorthosite in the centre of the investigated complex is associated with large amounts of monzonitic and more mafic rocks which span the compositional range between norite, gabbronorite and ferrodiorite. The ferrodiorites occur as bodies and dykes within and at the margins of the anorthosite and in the country rocks. Many of these mafic rocks are fine-grained and are believed to reflect liquid compositions. Some of them clearly postdate the anorthosite, whereas others appear to be contemporaneous with it. (Forkortet)