The Falun Area VMS Projects
Background
The historic polymetallic mining district of Bergslagen is
located approximately 200 km west and northwest of Stockholm, in
the south-central part of Sweden. Eastern Highlands AB (EH) holds
nine individual exploration licenses in the district. The licenses
are currently under an Exploration Permit and ownership is 100%
EH's. The licenses cover a total area of 175 km2 of
which six lie within the same supracrustal belt that contains the
famous Falu Copper Mine. The Falun Area VMS
Projects are subdivided into four exploration target
areas:
- The Samuelsdal Exploration Target
- The Holmen Exploration Target
- The Mortenberg Exploration Target
- The Leksand Exploration Target
Geology
The Bergslagen regional geology in the license areas is
dominated by Svecofennian metavolcanic supracrustal rocks. The
supracrustals have been intruded by Svecofennian orogenic
granitoids generally considered to be co-magmatic with the volcanic
sequence. During the orogenic build-up the supracrustals have
undergone at least two deformational phases and have been
metamorphosed to amphibolite facies. The region contains a
diverse range of ore deposit types dominated by polymetallic VMS
type with lesser carbonated or quartz banded iron formations,
skarn-type Fe-Mn mineralization, and possibly larger IOCG type
mineralizations.
The Samuelsdal Exploration Target was
discovered by TEM survey and is situated in the immediate vicinity
of the Falu Copper Mine. The target is modeled to be at a shallow
depth of ca 75-100 meter. The EM conductor is approximately 200 x
300 meter wide and given the close proximity of the Falu Copper
Mine this target area is very promising. In addition to promising
TEM data geochemical assays results show significant gold and
copper content in till samples.
The area has great potential for hosting a large-size VHMS
deposit similar to the Falu VHMS type mineralization. The style of
mineralization at Falu Copper Mine was massive sulphide ore
comprised of sphalerite, galena and chalcopyrite with lesser
Copper-Gold stringer mineralization and Gold mineralized quartz
veins. The Samuelsdal Exploration Target is a shallow near mine
drill target and planned to be drilled in nearby future.
Project Highlights: A deep VMS
ore body (Zn, Pb, Cu, Au) is situated within our near-mine
license.
The Holmen Exploration Target was discovered by
TEM survey and is situated 7.0 km west the Falu Copper Mine within
the same supracrustal belt. Geological, geophysical and geochemical
data indicate that a blind VMS style mineralisation (similar to
Falun Mine) might occur at depth in the Holmen area.
Our exploration in the area indicate that the Holmen target
could be a large VMS replacement-like deposit hosted by carbonate
beds and altered felsic metavolcanic rocks. Structural data and
observation of carbonate beds suggest that the outlined geophysical
and geochemical anomaly is enclosed in a large steep standing
synformal fold. This observation is favourable for sulphide
mineralizations as observed in most of the large-scale
mineralisation systems in NW Bergslagen such as the Falu Copper
Mine and Garpenberg deposits. The Holmen Exploration Target is
planned to be tested by a diamond drill campaign in autumn
2011.
Project Highlights: A potential blind VMS
deposit 7 km SW of Falun within the same supracrustal belt.
The Mortenberg Exploration Target area is
situated in the NW part of the Bergslagen region. The area has
historically been exploited for iron, copper and nickel in
particular the historic iron mines of Sörskog, the nickel mine of
Slättberget and the copper mines of Mårtanberg.
The Mortenberg exploration target area is virtually unexplored
with modem exploration techniques, with the exception of a stream
sediment survey conducted by Luossavaara-Kiirunavaara Aktiebolag
(LKAB) during the mid 1980's. This survey suggested significant
Zinc, Lead and Copper mineralizations in the metavolcanic dominated
area. A major regional ductile shear zone is bordering the
prospective metavolcanics. The area is desolated and great for
TEM/MAG surveys.
Project Highlights: High geochemical anomalies
in prospective metavolcanics with potential for Falun VMS type
mineralization and alteration.
The Leksand exploration target area is situated
the easternmost part of the Bergslagen region. The area has been
explored up through the mid 1900th resulting in a
resource estimation of the magnetite ore body at 17 Mt @ 30% Fe.
This calculation was based on a limited amount of shallow (< 80
m) drill core data.
EH has surveyed the area with helicopter borne TEM/MAG and
re-examined drill cores from the southern part of the
mineralization. Our interpretation of the new data set ad further
potential for target. TEM and MAG data indicate a much larger ore
body up to 3100 m in length with anomalies continuing down to at
least 500 meters. The TEM data show a conductive area directly
associated with the magnetite mineralization which could be
interpreted as either a high grade (pure) magnetite mineralization
or sulphide mineralization. The drill core data suggest a
tight to isoclinals folding of the ore body and it is likely that
the mineralization is repeated several times.
Project Highlights: The Leksand Exploration Target is
potentially the largest unmined iron oxide deposit in Bergslagen
region.
Last updated: November 23, 2011
Facts
Location: Sweden
Ownership: 100%
Licence area: 175 km2
Status: Exploration license
Type of Ore body: VMS, BIF, Skarn, ore- and replacement
mineralisation
Commodity: Zinc, Lead, Silver, Copper, Gold
Simplified regional geology map of the Bergslagen area. The
position of apatite-rich (blue dots) and goldbearing (red dots)
iron ores are indicated.
Falun Mine, an UNESCO World Heritage site.
Massive Zinc, Lead and Copper sulphide-rich outcrop from NW
Bergslagen.
Photo showing Copper stringer mineralisation in highly altered
footwall succesion in licence area in Falun.