(Pages 295-296) Chemical composition of external rind and core of a ferromanganese concretion from lake Irrsee, Austria (anciently called, Zellersee zum Mondsee)

The deposits studied by the author are crusts and coatings of manganese oxide (mixed psilomelane, wad and limonite) on a consolidated marl. They were recovered from the lake bottom at two points approximately 2 km apart and at a depth of about 18 to 22 m. The lake is deeper than a typical bog swamp and its bottom is a soft blueish and clayey marl. Some of its banks are occupied by moorlands. The occurence of manganese concretions seems to be limited to a few small perimeters. The author analysed both the rind and the carbonate core of one of these concretions (NOTE: The Austrian lake anciently called Zellersee zum Mondsee is now known as Irrsee).