Geologi og petrografi på Nord-Karmøy.

Abstract

The athor gives a description of rocks and tectonics on the northern and central part of the island of KarmThe athor gives a description of rocks and tectonics on the northern and central part of the island of Karmøy, West-Norway, and concludes with an interpretation of the observations and a geologic history of the area. The following rocks are described, proceeding from the youngest to the oldest, that is from the north to the south: Greenschist, lava greenstone and amphibolite. These rocks are intruded by epidiorite and trondhjemite. Youngest is the quaternary till: boulders, sand and clay. The tectonic processes have given rise to a syncline that in general follows the eastern shore line of Karmøy, with NNW-plunge. West of the syncline the strike is northwesterly with increasing dip angle westover. East of the syncline the strike is northerly. The lineation of the rocks goes parallel with the above mentioned syncline (B-lineation), another one (B') goes oblique to the B-lineation. There are ruptures that strike N-S with more or less horizontal movements and others with strike NW-SE that are overthrusts. Both of them have to some extent formed the topography. All of the rocks are metamorphosed in the \"greenschist-facies\". The age of the rocks is Lower Ordovician.