During Renzy Mines Ltd. exploration programme in 1972, an iron-formation was found in the Midternæs area north east of Ivigtut, South-West Greenland. It contains up to 32.9% Fe. The dominant mineral is greenalite, with minor amounts of magnetite, siderite and quartz. It was found in the northernmost part of the Ketilidian supracrustals (? 1800 m.y.), which are non-metamorphosed or very weakly metamorphosed. The iron-formation is suggested to be of submarine-exhalative origin, and precipitated in a moderately deep sea at low atmospheric O₂ pressure.