Geologisk kartskisse over trakterne omkring Velfjorden med beskrivelse

Abstract

Forkortet: Velfjorden is situated in northern Norway, in the southern part of the district of Helgeland, in 65\u00B0 30'N. A geological map of the region is given on pp.8 and 9. The eruptive rocks here are granite, gabbro and serpentine. The granite frequently appears in the form of large intrusive sheets between the stratified rocks. In several cases the gabbro is also intruded in this manner. Both the granite and the gabbro generally show a distinct foliation, which is the result of strong regional metamorphism acting during the folding of the Scandi- navian mountainchain. The stratified rocks here, as in the greater part of the northern Norway, are gneiss, mica-schist and crystalline limestone (marble). They are all of them older than the eruptive rocks in the region. Lowest lies a formation of mica-schists with mighty layers of crystalline limestone; above this follows conformably gneiss, with a few layers of crystalline limestone interstratified. No fossils have hitherto been found in this region; but Tellef Dahll has assumed that the formation of mica-schists and marble belongs to the Cambrian system, an assumption which has been confirmed rather than disproved by the observations of recent years.