Fungal Growth and Iron Reduction in Swedish Alum Shales

Abstract

IN the course of laboratory tests of the heap leaching of uranium from alum shales, evidence was obtained for the existence of an apparently indigenous fungal flora. The deposits concerned, which represent part of the upper Cambrian series, outcrop and are being worked for uranium in the Billingen mountain area of central Sweden¹. They have a high content of pyrite, varying between 12 and 15 per cent, which is finely disseminated and often occurs in the form of framboids. The shales also have a high content of organic matter, varying between 20 and 30 per cent, which occurs mainly in the form of kerogen, which is why they have been worked as oil shales in other areas of central Sweden.