The author is studying various manganese coated river pebbles which had been given to him for evaluating their chemical properties. Samples were provided for the confluence of the Vistula and the Dunajec river in Poland by Mr. W. Petraschek. Other samples had been acquired earlier from Pr. A. Fraunhofer in the river bed of the Enns river near the town of Ernsthofen in Austria.

From 1983 until 1989 NOAA-NCEI compiled the NOAA-MMS Marine Minerals Geochemical Database from journal articles, technical reports and unpublished sources from other institutions. At the time it was the most extended data compilation on ferromanganese deposits world wide. Initially published in a proprietary format incompatible with present day standards it was jointly decided by AWI and NOAA to transcribe this legacy data into PANGAEA. This transfer is augmented by a careful checking of the original sources when available and the encoding of ancillary information (sample description, method of analysis...) not present in the NOAA-MMS database.

Supplement to: Dittler, E (1924): Manganführende Flußgerölle = Manganese rich river pebbles. (now in Springer Link), Tschermaks mineralogische und petrographische Mitteilungen, 36(3), 164-169