IMPORTANCE OF GEOCHEMISTRY - THE BLACK ANGEL LEAD-ZINC MINE, GREENLAND

The Black Angel lead-zinc mine operated from 1973 to 1990 using seawat er in the froth flotation mill process and submarine tailings disposal to the Affarlikassa (''A'') fjord Within 1 year from startup, elevate d lead and zinc levels were found in Qaumarujuk (''Q'') fjord outside the receiving ''A'' fjord. Elevations in cadmium also were found at a later date. Extended geochemical and oceanographic studies established that the ore and the tailings contained significant oxidized lead and zinc minerals soluble in the ambient pH seawater and confirmed that s easonal under-ice destratification of the water column allowed dispers al over the sill between the ''A'' and ''Q'' fiords. A shoreline waste rock dump also contributed to the contamination. Detailed mineralogic , leaching, and oceanographic studies, which are now conventional at p roposed new mines, would have produced more detailed information on wh ich to base the decision whether submarine tailings disposal (STD) was appropriate at this particular site.