Discordant U-Pb isotopic system in zircons from a granite north-west of Frederikshåbs Isblink, Fiskenæsset region

Abstract

Extensive sampling was carried out in parts of the Fiskenæsset region during the 1971 field season with the aim of providing suitable matenal for isotopic age determinations. The total area covered by the mapping programme was so large and the geological problems so varied that it was decided to initiate this study by looking in detail at a small number of rock types in one or two sub-areas. Once isotopic relationships are known in these areas it is hoped to extend the work to embrace other problems in the region. The laboratory work is in progress at present and already some preliminary results have been obtained (Feb. 1972).It is the purpose of this report to discuss the age relationships of zircons extracted from a single 100 kg sample of granite from the mapping area of Hopgood (see plate 1).