Rare-earth elements in the Skaergaard intrusion

Abstract

The chilled marginal gabbro of the Skaergaard intrusion, East Greenland, is very similar in absolute and relative rare-earth abundances to other gabbros that have been studied. The rocks from the layered series that were analyzed all had rare-earth contents similar to that of the chilled gabbro, except for the specimen from the very top of the series, which was enriched more than ten times. The rare earths appear to have become increasingly concentrated in the magma as solidification progressed, but there was little change in relative abundances. No quantitative sympathetic variation between the rare earths and any major element was observed. Some minor fluctuations in rare-earth abundances appear to be correlated with variations in feldspar contents of the intrusion. It does not appear to be possible to explain the partition of the rare earths by the logarithmic theory.