Raipas og kaledon i strøket omkring Repparfjord, Vest-Finnmark.

Abstract

In the Repparfjord area rocks of the Precambrian Raipas System occur in an inlier, which is directly overlain by allochtonous Caledonian rocks with a tectonic unconformity. Any autochtonous Eocambrian and younger sediments once existing above the basement of Raipas rocks were squeezed out during the thrusting of the Caledonian nappes. The lower division of the Raipas sequence consists of volcanic greenstones and greenschists which are followed by a light sandstone and a dark somewhat sandy shale. The upper division consists of coarse-grained feldspathic sandstone (sparagmite) overlain by a conglomerate with a greenish schistose matrix, both deposits of a post-orogenic molasse type, there probably exists an unconformity due to erosion between these and the underlying deposits. The Raipas rocks are unmetamorphosed or nearly so they contain intrusions of gabbroid and ultrabasic rocks (serpentinites). The allochtonous Caledonian sequence has a lower division of banded quartzschists and an upper division of massive, coarse-grained garnet micaschists. The quartz-schists, with intercalated bands of micaschist, are composed of quartz, muscovite, biotite and garnet with some albite-oligoclase and clinozoisite or epidote. The garnet micaschists of the upper division are rather rich in oligoclase.