ON THE GEOLOGY OF THE MIRNYY STATION AREA

The U. S. S. R. -IGY Antarctic station, Mirnyy 66°31'S. 93°E.], is situated on four outcrops of Precambrian charnockitic granite, crystalline schist, and gneiss. The four mounds contain numerous angular xenoliths, generally dark schist and gneiss, denoting a palingenetic origin for the bedrock. Quartz veins and sulfide mineralization indicate later hydrothermal activity. The mounds are cut by two major fissure systems perpendicular to each other and several secondary fissure systems. In general, the offshore islands (the Haswell Islets) and the mounds are similar to the ancient Antarctic shield and are, therefore, considered to be a part of it. --Editor.