PRECIOUS METALS IN MAGMAS OF EAST GREENLAND - FACTORS IMPORTANT TO THE MINERALIZATION IN THE SKAERGAARD INTRUSION

A survey of precious metals, Ni and Cu levels, and their mutual relati onships in several magma suites of the East Greenland volcanic passive margin shows that the magma type which was parental to the Skaergaard intrusion was markedly enriched in Pt, Pd, and especially Au and rela tively depleted in Cu compared to the preceding voluminous plateau bas alt volcanism. It is likely that elevated levels of platinum-group min erals (PGM) and Au were critical to the generation of ore-grade precio us metals in the intrusion. The discovery of a major PGM and Au deposi t within the intrusion combined with these results suggests a set of c riteria which might be critical to the formation of Skaergaard-type PG M deposits elsewhere in the province and worldwide. The Skaergaard min eralization appears to be a hitherto undescribed class of PGM and Au m ineralizations.