Stratigraphy and structure of the northern part of the Repparfjord - Komagfjord window, Finnmark, Northern Norway.

Abstract

In the northern district of the Repparfjord-Komagfjord Window, supracrustal and intrusive rocks of Early Proterozoic age are unconformably overlain by a thin sequence of Vendian sediments. Both of these units are overthrust by allochthonous rocks of the lavas, tuffs and sediments of the Raipas Supergroup and intrusions of the Raudfjell Suite, regionally metamorphosed at greenschist facies during the polyphase Svecokarelian Orogeny, c. 1840 Ma. The c. 8 km thick supracrustal sequence is divided into four groups and eleven formations on a lithostratigraphic basis. The lithological characteristics of these units are described and compared with rocks of similiar age elsewhere in N. Norway. The stratigraphy and sedimentology of the thin (<200 m thick), autochtonous, Vendian cover sequence is also described. The caledonian Orogeny resulted in complex deformation of the autochtonous cover as well as considerable reactiviation of the underlying basement.