Geophysical and geological investigations of graphite occurrences in Vesterålen and Lofoten, Northern Norway 2017

Abstract

As a part of the MINN project (Minerals in Northern Norway), a helicopter-borne geophysical survey was performed in Lofoten and Vesterålen in 2013. Electromagnetic data from this survey showed up anomalies that may be caused by large graphite mineralisation. With financial support from Nordland County, NGU has performed geophysical and geological follow-up work to 1) confirm the existence of graphite and 2) Briefly evaluate the quantity and quality of graphite structures.The project started in 2015 and the results from the first two years are reported by Gautneb et al. (2017) and Rønning et al. (2017). Follow-up work performed in 2017 is reported in this report. 15 locations have been investigated in total in 2017. The degree of detail in these studies varies from just a few lines of simple electromagnetic measurements (EM31) to electric measurements such as Self Potential (SP), Charged Potential (CP) and Electric Resistivity Traversing (ERT) in combination with Induced Polarisation (IP). In two areas, Sommarland and Haugsnes in Bø municipality, two short core drilling bore holes were made. The selection of follow-up objects was based on both magnetic and electromagnetic data from helicopter-borne measurements.All results from the 2017 work are reported here. Where possible, the volume of graphite is estimated based on the total strike length, the width of individual zones (from drilling, observations and width of EM31 measurements) and an assumed depth extent of 100 m. In these areas, an estimation of graphite tonnage is also given.