Gl. Cumming et al., FURTHER ANALYSES OF RADIOGENIC MINERALS FROM THE BIDJOVAGGE GOLD-COPPER DEPOSIT, FINNMARK, NORTHERN NORWAY, Mineralogy and petrology, 49(1-2), 1993, pp. 63-70
We recently reported U/Pb and Sm/Nd dates on davidite from albitic fel
sites hosting the gold-copper mineralization of the Bidjovagge gold-co
pper deposit of northern Norway (69-degrees-17'N, 22-degrees-29'E). Is
otopic dating of the north-south trending Proterozoic Kautokeino green
stone belt host rocks is sparse and confirmation of the dates was desi
rable, since the U/Pb data in particular were highly discordant and th
erefore somewhat uncertain. We have now supplemented the earlier measu
rements with U/Pb dating of uraninite from the felsites. The new urani
nite data yield a well defined upper intersection with the concordia a
t 1837 +/- 8 Ma, somewhat younger than the age of 1885 +/- 18 Ma obtai
ned on the davidites. The fact that the two minerals are apparently di
fferent in age lends support to the suggestion of a metamorphic origin
of this deposit since a rather long period of cooling subsequent to m
etamorphism is indicated.