Nordic Nickel (ASX:NNL) reports recently completed downhole electromagnetic (DHEM) surveys have ‘enhanced’ the discovery potential at the Pulju Nickel Project in Finland.
The company says DHEM data provides an image of the sub-surface lithologies which are conductive, including precise depths to the conductors. This information will be further utilised in refining the existing electromagnetic (EM) models and planning additional ground based EM surveys.
In total, 17 historical drillholes have now been surveyed by Nordic, and the results of the recent DHEM survey and the previously acquired ground based fixed loop electromagnetic (FLEM) survey are encouraging and confirm the presence of multiple targets at the Hotinvaara Prospect.
The FLEM survey found the potential for near-surface massive nickel sulphide lenses within the prospective cumulate ultramafic rocks, as well as extensions to the near-surface disseminated nickel sulphide zones adjacent and external to the maiden mineral resource estimate (MRE) of 133 million tonnes @ 0.21% Ni for around 278,000 tonnes of contained nickel.
It also confirmed the potential for ‘high-grade’ massive sulphide (Sakatti-style) mineralisation at depth below the known zones of mineralisation.
Nordic Nickel Managing Director Todd Ross said: “Geophysics is a critical tool for unlocking the potential and extent of the mineralisation at Pulju and DHEM was instrumental in the discovery of the world-class Sakatti Deposit in the Central Lapland Greenstone Belt.
“We are incredibly fortunate to have the benefit of over 10,000m of historical drilling at Hotinvaara, combined with the fact that many of these holes remain open”
We are incredibly fortunate to have the benefit of over 10,000m of historical drilling at Hotinvaara, combined with the fact that many of these holes remain open.
The DHEM data collected, combined with the historical drill data, provides an accurate image of the mineralogy, location and depth of the EM conductors observed, revealing multiple further targets that will be tested as part of our upcoming diamond drilling campaign starting in January 2023.”
Nordic reports 17 of the original 51 holes drilled by Outokumpu have been measured with DHEM within the Hotinvaara Exploration Licence and 7 more have been found to be open, and will be surveyed in winter.
Additional DHEM surveys have also been completed on 14 historic drillholes, adding to the 3 holes surveyed in mid-2021. The company says the Hotinvaara Prospect area represents 2% of its exploration area in the Central Lapland Greenstone Belt in Greenland.
Modelling of the DHEM data after removing the plates related to logged black shales has yielded 56 conductor plates, 11 of which are related to nickel sulphide intersections grading over 0.5% Ni.
The company says the conductor model has highlighted 3 new target areas where near-surface massive sulphide mineralisation could be located, and provides ‘high-quality’ targets for Nordic’s upcoming maiden drilling program.
These new targets include the Southwestern Prospective Zone, the Central Prospective Zone and the Northern Prospective Zone.
Nordic reports the results from the recent DHEM survey provide further insights into the potential for deeper massive sulphide mineralisation at Hotinvaara, noting the survey imaged both sulphide horizons and stratigraphic horizons (graphitic black shales).
While the black shales do not always contain ‘ore-grade’ mineralisation, the company says they are important in allowing nickel mineralisation to develop in adjacent areas.
The FLEM survey conducted in mid-2021 modelled deep conductors up to 1,500m below the Hotinvaara MRE, and this conductor is interpreted by Nordic to be a response to a stratigraphic horizon, most likely sulphate-bearing or graphite-bearing lithologies.
This stratigraphic horizon is considered by the company to be a ‘critical ingredient’ for the localisation of nickel-copper massive sulphides, and Nordic plans to test this horizon along with the base of the cumulate layer in its upcoming drill program scheduled for January 2023.
Nordic Nickel is a nickel exploration company focused on its assets in the Central Lapland Greenstone Belt located in Finland. The company’s projects include the Pulju Nickel Project and the Maaninkijoki 3 Nickel Project, both located in northern Finland.
Images: Nordic Nickel Ltd
