Among the geological discoveries of the end of the 19th century, one of the most remarkable and certainly most important from the economic point of view, is that lime phosphate deposits have been recorded at various levels in a great many fields. The subsequent development given to the phosphate industry by that of agriculture needs have attracted a great interest in phosphate deposits. This, interest quickly developed for the phosphatic concretions dredged durin the Challenger expedition in the vicinity the Cape of Good Hope and in the Indian Ocean in a line drawn South from Africa to Marion Island. This paper describes the sedimentary environment of these finds and measurements of their chemical contents.

Samples have been dessicated at 110 °C and futher ignited at about 1000 °C. Acid insoluble part has been seperated using nitric acid.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1989 NOAA-NCEI compiled the NOAA-MMS Marine Minerals Geochemical Database from journal articles, technical reports and unpublished sources from other institutions.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: Renard, A F (1889): Les concrétions de phosphate de chaux draguées au large du Cap de Bonne-Espérance. Bulletin de l'Académie Royale de Belgique, 3éme Série, 18(12), 641-665