The graphite occurrences of Northern Norway, a review of geology, geophysics, and resources
Gautneb, Håvard; Rønning, Jan Steinar; Engvik, Ane; Henderson, Iain; Larsen, Bjørn Eskil; Solberg, Janja Knezevic; Ofstad, Frode; Gellein, Jomar; Elvebakk, Harald Kristian; Davidsen, Børre
Peer reviewed, Journal article
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Date
2020Metadata
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Abstract
There are three provinces in Northern Norway in which occurrences of graphite are abundant; the Island of Senja, the Vesterålen archipelago, and the Holandsfjorden area. From these provinces, we report graphite resources from 28 occurrences. We use a combination of airborne and ground geophysics to estimate the dimensions of the mineralized areas, and, combined with sampling and analysis of the graphite contents, this gives us inferred resources for almost all the occurrences. The average TC (total carbon) content is 11.6%, and the average size is 9.3 Mt or 0.8 Mt of contained graphite. We demonstrate that the Norwegian graphite occurrences have grades and tonnages of the same order of magnitude as reported elsewhere. The graphite-bearing rocks occur in a sequence that encompasses carbonates, meta-arenites, acid to intermediate pyroxene gneisses, and banded iron formations metamorphosed into the granulite facies. Available radiometric dating shows that the graphite-bearing rocks are predated by Archean gneisses and postdated by Proterozoic intrusions of granitic to intermediate compositions. The graphite occurrences of Northern Norway, a review of geology, geophysics, and resources