The historical mining town of Røros viewed from the slag heap. The former smelter is on the far right.
Near the historical mining town of Røros, the Nordgruve Development Area (88 km2) is composed of three mining licences being acquired from Holtålen kommune (municipality) together with seven exploration licences around Kongens Gruve and the Fjellsjø deposit issued to NAML in 2015 and two exploration licences along strike of the Hersjø deposit issued in 2016. The Hersjø deposit has an independently estimated unclassified resource of 5.55Mt at 1.05% Cu and 1.27% Zn. Supported by Traxys Europe SA as a 7% shareholder, NAML is in the process of upgrading the resource to JORC standard.
Improved Project Structure
Following the announcement1 by Intex Resources ASA to terminate its earn-in agreement with NAML and surrender its 31 exploration licences in the Røros district, NAML and Hessjøgruva AS have agreed2 on the principal terms of acquisition by NAML of three mining licences held by Hessjøgruva AS containing the 5.55Mt Hersjø deposit. In 2015, NAML was granted seven exploration licences east of Hersjø, then in 2016 two exploration licences surrounding and along strike of the Hersjø deposit.
This acquisition, in exchange for a deferred payment and a 2% net smelter return royalty, allows NAML to proceed with a staged feasibility study and development programme on the basis of a 100% interest in the three mining licences being acquired from Hessjøgruva AS and NAML's nine exploration licences.
NAML is assessing additional opportunities to increase its 'base metal' mineral resource platform in Central Norway and elsewhere in Scandinavia.
1Oslo Stock Exchange, 29 January 2016 2Heads of Terms signed 04 March 2016
An audit of the Hersjø drill core stored by NGU at Løkken, southwest of Trondheim, indicates that 9,710m of the 12,200m of core from the 66 holes drilled in 1970–1977 are available for relogging (79%). About 52% of the drilled intersection meterage is available for resampling and independent analysis, as well as previously unsampled core from the footwall and hangingwall. New assays will include gold and silver, which were excluded from historical assays. Drill core from several other targets in the Røros district is still available for relogging and resampling.
As part of the resource upgrade to JORC compliance, NAML contracted Norconsult AS to survey the drillhole collar locations on the Hersjø deposit using a total station. The survey provided precise co-ordinates of 53 of the 66 holes (80%). NAML has recovered original downhole survey data from archives in Norway and Sweden.
3D model and resource estimate
Using all the available historical exploration data, the unclassified resource as re-estimated by NAML and Aurum Exploration (February 2017) indicates a total of 5.55 Mt at an average grade of 1.05% copper and 1.27% zinc above a 1.0% CuEq cut-off. Compared with the previous NGU resource estimate, for which downhole survey data was unavailable, the new estimate represents an additional 14.7% in the quantity of contained copper, and an additional 68.5% in the quantity of contained zinc in the resource above a 1.0% CuEq cut-off.
COPPER-ZINC DEPOSITS IN THE TRONDHEIM NAPPE COMPLEX
SIMPLIFIED GEOLOGY & LICENCE MAP OF THE RØROS DISTRICT
NAML and Hessjøgruva AS have agreed on the principal terms of acquisition by NAML of three mining licences held by Hessjøgruva AS containing the Hersjø deposit.
HERSJØ 3D MODEL
NAML has geologically modelled the Hersjø deposit in Micromine as the basis for the independent unclassified resource estimate by Aurum Exploration in February 2017. Variography, geostatistical modelling and resource estimation were carried out using Datamine software.
Nordgruve Development Area
The Nordgruve development area (stippled red outline) showing the three mining licences (solid blue outline) to be acquired by NAML from Hessjøgruva AS, and NAML’s exploration licences (solid red outline).
The wider project area covers approximately 900 km2 of prospective ground where a helicopter electromagnetic survey has been flown; this has revealed anomalies both coincident with and additional to already known deposits and occurrences where very high grades of copper and zinc have been assayed in samples from outcrop and from dumps left by small-scale historical exploitation.
Knowledge Transfer Partnership
A knowledge transfer partnership (KTP) is currently being set up with the Scottish Universities Environmental Research Centre (SUERC) to establish a lithogeochemical framework for each of the deposits in NAML’s Nordgruve Development Area, using samples from historical drillcore and from outcrop. The KTP will aid the interpretation of the district tectonostratigraphy, which in turn will focus the search for new targets.