Longitude: -37, Latitude: 65.07
Loose blocks of nepheline syenite occur at Nagtivit in the mouth of Sermilik Fjord, Angmagssalik district. They are presumed to originate from a hitherto undiscovered intrusion high up the Fjord.
An apatite fission track age of 58.0±2.8 Ma on nepheline-sodalite syenite was obtained by Gleadow and Brooks (1979, Table 1), while Rex (in Gleadow and Brooks, 1979, p. 51) obtained 54.9±1.6 Ma by K-Ar on hornblende.
GLEADOW, A.J.W. and BROOKS, C.K. 1979. Fission track dating, thermal histories and tectonics of igneous intrusions in East Greenland. Contributions to Mineralogy and Petrology, 71: 45-60