Bleikvassli Geology

The Bleikvassli property is underlain by highly deformed, moderate to high grade metamorphic units of the Anders Larsa Group and the stratigraphically lower Kongsfjellet Group. In the area of the Bleikvassli mine, the Anders Larsa Group is to the west of the Kongsfjellet Group; elsewhere on the property the relationship in more complex, and NGU mapping (NGU, 2019) suggests that a complex fold geometry may emplace an arm of the Anders Larsa Group south of the mine area. The Anders Larsa Group is composed primarily of thick sequences of marble, mica schist and amphibolite; the underlying Kongsfjellet Group is more varied, containing garnet-mica schists, feldspathic gneisses, calcareous schists, marble and amphibolite which are interpreted to be metamorphic products of mafic volcanic, clastic sedimentary and carbonate units.

The Kongsfjellet Group hosts the Bleikvassli Pb-Zn-Cu-Ag deposit near its top within a unit termed the “Mine Sequence”. The Mine Sequence has an approximate maximum thickness of 1 km, and is subdivided into upper and lower portions. The Upper Mine Sequence contains marble and calc-silicate bands, kyanite-mica schists and thin layers of graphitic schist; the Lower Mine Sequence lacks the carbonate units of the upper, containing kyanite-mica schists, graphitic schists, feldspathic gneisses and quartzites. The zone of historically mined mineralization is hosted within the Lower Mine Sequence.

It has been suggested that the Anders Larsa and Kongsfjellet groups are spatially and temporally related; the Kongsfjellet Group represents a deep-water back-arc basin and the Andres Larsa Group a shelf sequence along the continental margin. The Bleikvassli deposit is situated within the upper several hundred meters of the Kongsfjellet Group, placing it quite proximal to the contact between the two groups.

Property Mineralization

Historical records indicate that the Bleikvassli orebody produced a total of 5.0 Mt of ore at 4% Zn, 2% Pb, 0.15% Cu and 25 g/t Ag over 40 years of mine life from 1957 – 1997. The majority of historical work concurs that the deposit is a sediment-hosted massive sulphide Pb-Zn deposit of the SEDEX category. This deposit was originally described as a VMS system, but the company and the NGU believes the project shares the characteristic of a SEDEX type deposit, with the Lundin Zinkgruvan mine in Sweden being a Scandinavian analogue. The deposit consists of stratiform/stratabound lenses of lead-zinc-silver massive sulfide mineralization, which locally grades into more copper and gold-rich compositions

Production came from two lenses (southern and northern) connected by a zone of disseminated sulphides. Together, these two lenses and intervening zone of disseminated mineralization compose a body at least 1500 m in strike length and 100 m – 300 m width which dips moderately towards the northwest with a plunge to the north. Within these boundaries, the mineralized body is highly deformed, primarily by a set of southwest plunging asymetrical S-shaped folds with long northwest and short southeast limbs (Cook et al., 1998). The southern end of the mineralized zone is truncated tectonically, while the northern extension is interpreted based on geophysical surveys to continue under Lake Bleikvatnet. The main surface exposure of the orebody is a 500 m long portion of the southern lens southeast of the mine entrance. Thickness varies from 15 m in portions of the southern lens to 2 – 3 m in the northern lens; the majority of production came from the southern zone. Production at the southern lens came largely from two styles of mineralization: pyrite- and pyrrhotite-dominated massive sulphide zones. The pyrite-dominated is the more abundant of the two and is composed of medium-grained pyrite-sphalerite-galena with minor quantities of chalcopyrite and pyrrhotite. The (less abundant) pyrrhotite-dominated mineralization has similar associated amounts of sphalerite and galena to the pyrite-dominated ore but higher quantities of chalcopyrite. In addition to these two types of massive mineralization, sulphide mineralization is also found in disseminated and wall-rock mineralization. Disseminated mineralization is described as being composed of coarse crystals of pyrite disseminated along schistose partings proximal to the massive ore zones. Wall-rock mineralization is much more varied in style, with a wide variety of sulphide±quartz veins cutting wall rock primarily on the hanging wall side of the deposit. Sulphide species vary greatly between veins (sphalerite, galena, pyrrhotite-chalcopyrite, and quartz-galena veins are all described) and there are clearly a multitude of veining styles present. It is unclear if any commercial production was undertaken from the disseminated and wall-rock styles of mineralization.

Apart from the main mineralized body mined at Bleikvassli Gruven, there are two zones of known mineralization in bedrock on the property: first, a set of grab samples from the NGU rock sample database taken approximately 4 km southeast of the mine, and second, several mineralized intercepts in exploration drillholes at the Brunesbekken showing approximately 1.5 km south of the mine.

The grab samples from the NGU database are located along what they have mapped as a contact between garnet-mica schist and meta-rhyolite units (likely of the Kongsfjellet Group). It is worth noting that the unit identified as meta-rhyolite on the NGU 1:250,000 mapping dataset coincides with what workers more familiar with the mine geology identify as kyanite-mica schist, microcline gneiss and quartzite. Additional work is necessary to resolve this discrepancy, but for the present it is interesting to note that this package directly underlies the main mineralized zone at the mine. Of the 35 samples taken by the NGU from this contact zone, 8 (distributed over a strike length of nearly 2 km) contain combined Pb+Zn values in excess of 5% and 28 are in excess of 1%.

The exploration drillholes at Brunesbekken are spread out over an area of approximately 600 m x 400 m, 1.5 km directly south of the mine. The drillholes intercept geology similar to that mapped at surface; namely a sequence of amphibolite, calcareous schist, muscovite schist, biotite-muscovite schist and kyanite-garnet-mica schist. Several of the drillholes intercepted sulphide mineralization hosted in a the biotite-muscovite schist unit; the best reported intersection is from drillhole 1-97, and is reported to contain 1.22% Cu, 1.27% Zn and 0.14% Pb over 4.2 m. None of the other drillholes contained any samples in excess of 1% copper, lead or zinc values.

Though extremely early stage, these results suggest that Pb-Zn mineralization on the property is not confined solely to the vicinity of the Bleikvassli mine or its directly correlative stratigraphy.  Neither EMX nor Norra have conducted sampling or exploration work on the Bleikvassli property following staking of the exploration rights by EMX.

Rock samples collected by Swanton (2018) were selectively taken from visibly mineralized areas of bedrock, and as such can be considered representative of mineralization at the locations sampled, but not necessarily of the geology of the area as a whole. Sample M411359 is composed of a series of chips taken by hand from sulphide mineralization exposed in a portion of the wall ~25 m into the underground workings (east) from the portal entrance to the Bleikvassli mine. The surface of the wall is highly oxidized, but inspection of fresh faces shows the presence of pyrite, sphalerite, galena and chalcopyrite in the sample; these observations are backed up by assay values showing 5.6% Zn, 3.4% Pb and 0.5% Cu. The second sample (M411360) was taken by hand from an outcrop at the entrance to a small pit approximately 150 m northeast of the mine entrance. Material was selectively taken from one of the bands of massive sulphide which are present in the outcrop; mineralogy and base metal assay results were similar to the underground sample, returning 9.3% Zn, 0.76% Pb, and 0.1% Cu. Precious metal values vary greatly between the samples, though it is not possible based on the limited data available to speculate as to a cause for this variance.

Mapping shown in previous publications identifies the area from which both of these samples were taken as the outcropping expression of the southern lens of the Bleikvassli orebody. As such, these two samples are likely representative of the type of ore mined from this lens, and thus are valuable in providing confirmation of the composition of mineralization at the Bleikvassli property via modern analytical techniques.

Bleikvassli Grab Samples (Swanton 2019)

Sample ID	Pb (%)	Zn (%)	Cu (%)	Au (ppm)	Ag (ppm)	Notes
M411359	3.39	5.62	0.55	0.32	71.7	Composite sample of chips taken from sulphidic part of wall ~50 m in from the portal
M411360	0.76	9.3	0.1	0.068	4.26	Sample of sulphide-rich layer outcropping on the right-hand entrance to the pit

 

Reference: 2019 Technical Report on the Bleikvassli Project by David Swanton, M.Sc., P.Geo. dated March 4, 2019