Origin of iron ore nuggets ("Bohnerze") through weathering of basalt as documented by pebbles from the Herbstlabyrinth, Breitscheid-Germany
Ahmad Al-Malabeh, Stephan Kempe - (34/2,2005)
This study was conducted to investigate the origin of the iron nuggets that have been found in the Herbstlabyrinth at Breitscheid, northern Hessen/Germany. A total of ten pebbles were collected. Petrographically, the pebbles can be divided into three groups: rather fresh basalts, markedly or totally altered basalt (including the iron nuggets) and a dark sandstone. The iron nuggets originate through a progressing alteration (oxidation and hydration) of the basaltic pebbles. The geochemical study shows that the original fresh basaltic pebbles are of alkali type and belong to the Na-series. The magma that gave rise to them was primitive and originated in peridotite mantle source.