Precambrian stratigraphy in the Masi area, southwestern Finnmark, Norway.

Abstract

The rocks in the Masi area consists of a comformable stratigraphic sequence containing three formations. The lowest is the Gål'denvarri formation, mainly containing metamorphic basic volcanics. Above this is the Masi Quartizite with a conglomerate at its base. The upper formation in the Masi area is the Suoluvuobmi formation containing metamorphic basic volcanics, metagabbros, mica schist, graphitic schist and albite fels. The eastern part of the area is dominated by granites which have an intrusive relationship to all three formations. Remnants of the Archean basement situated further to the east probably occur within the younger granites. Nothing conclusive can be said about tha ages of the rocks, but for the Gål'denvarri formation an Archean age is considered most probable. The ages of the Masi Quartzite and Suoluvuobmi formation may be Svecokarelian, but based on correlation with rocks in Finland, Archean ages also seem likely for these units.