K/Ar Age Determinations from the Precambrian of Denmark

Abstract

K/Ar age determinations on granites and pegmatite from the island of Bornholm give results between 1255 and 1340 m.y. Ages between 1300 and 1500 m.y. are common in Scandinavia, Russia and North America. They are believed to represent a period of anorogenic plutonic activity.

K/Ar age determinations on core samples from deep tests made in Jutland and on Fyn give acceptable results between 800 and 900 m.y. for the crystalline basement. This indicates a relation to the 900-1200 m.y. orogenic episode recorded in Southern Norway and in Central Europe.