Assessment of anorthosite at Gudvangen Stein's property in Nærøydalen Aurland from a resource geology perspective

Abstract

An evaluation of the anorthosite resource at the property of Gudvangen Stein gives the following conclusions: \r- Large quantities of an unusually aluminium-calcium rich anorthosite are present at the property of Gudvangen Stein A\/S in Nærøydalen. The property forms part of a 100km2 large anorthosite massif extending 25 km southeastwards towards Mjølfjell at the Bergen railroad.\r- Two main varieties of anorthosite are present within the mining area of Nærøydalen. One type is a primary anorthosite where the almost monomineralic feldspar content is soluble in acids and thus well suited for processing that requires dissolving of the minerals. The second type is altered and fine-grained, with a white colour well suited for applications requiring light or white materials. Both types are well-suited material for rock wool production.\r- This aluminium-calcium-rich anorthosite is hard to find both in Norway and worldwide in large and homogenous quantities as in Nærøydalen. The Gudvangen deposit is world class in this category.\r- Millions of tons of anorthosite occur within Gudvangen Stein's property, and additional immense quantities are present in adjoining areas of the large Gudvangen-Mjølfjell anorthosite-massif. Thus raw material resources are practically unlimited.\r- Anorthosite has a wide range of potential uses, and the aluminium-calcium rich variety of the Gudvangen area has especially varied possible applications in addition to the present established markets of rock wool, asphalt and concrete.\r- The regulations of the Protected Landscape area and the recently acquired status of the Nærøyfjord region as a World Heritage Site gives room for further developments underground, based on the current mining areas of Gudvangen Stein. Environmental concerns are important, and future workings must not come in conflict with the protection regulations and any World Heritage status for the area.\r- The newly upgraded mining system at Jordalsnuten provides flexibility to handle both present production capacity and medium scale future expansion.