Investigation of talc from 1997-drillcores from the Nakkan depoist, Altermark, northern Norway.

Abstract

As a part of the development of the Nakkan deposit in Altermark a study focused on mineralogy has been carried out. Detailed field inspections of drill cores from 1997 and 1998 are described. The inspection shows that zones contaminated by amphibole are very few and small. XRD, XRF and microscopic analyses were carried out from selected samples from the 1997-drill cores. Microprobe analyses have been carried out on selected samples from the talc mine, Store Esjeklumpen and the Nakkan deposits, with specific attention to the Ni-content in the talc-lattice. From this study it seems clear that there are large variations in the NI-content in the talc-lattice. From this study it seems clear that the magnetite content is much lower than previously indicated by the method based on removal of magnetic matter. From the XRF-chemical analyses, a method is described and used to estimate the mineral content of the samples. No clear differences are found regarding the content of talc, breunnerite and chlorite. But unfortunately, very few samples from the mine have been investigated, and more samples are urgently needed in order to make reliable conclusions.