Radiometric age determinations on rocks from Spitsbergen

30 new radiometric age determinations of Spitsbergen rocks are detailed.Previously published data are listed for comparison giving a total of 76 determinations.The significance of these is discussed with the following general conclusions.1. Late Pre-Cambrian metamorphism occurred in some areas affecting at least part of the Hecla Hoek succession; its stratigraphical relationship is not clear.2. Intense and extensive Caledonian metamorphism and plutonism arc reflected in apparent ages ranging from 450 to 360 million years (m.y. ) .The later events may overlap with possibly late Silurian, and Devonian sedimentation.3. Some very localized intrusions with basic affinities give an apparent Carboniferous age. 4.Widespread basic intrusions generally evident as dolerite sills are of mid-Mesozoic age.