Opemiska Property
DESCRIPTION OF THE OPEMISKA PROPERTY The Opemiska property owned at 100% by Ex-In has a surface
of 5 km² and englobes two former underground copper-gold
mine: the Springer and the Perry mines.
Both were mined between 1953 and 1991, targeting narrow but rich veins. The first years, the ore sent to the mill averaged over
6% copper. Later the grade of ore sent to the mill went down to less than 3% Cu, partly because some of the ore came from a
small glory hole. Today, many former underground mines are
being mined using open pit to extract large volumes of lower
grade ore. So far, 14,504 DDH and 303,433 assays were digitized from
original logs and hundreds of maps and sections were digitized
and geo-referenced. All this work has allowed us to build a 3D
view of the old infrastructures and DDH (Figure 9) and thus,
help us determine the geological potential and to define more
accurately areas of potential. Since 2013, the collaboration with
our group of consultants RPA (Roscoe Postle and Associates)
allowed us to define, between 500 and 1,500 feet below the
surface, a large volume of ore with economic values of copper
and gold.
GOAlS
We believe that this ore can be mined with profit by an efficient
bulk mining operation, either from the surface or underground
high volume, such as at Gaspé Copper and there is enough ore
available in Springer and Perry mines to start an open pit mine.
The main objectives for Ex-In in the coming months are:
1. Define with new drilling the surface’s extension of the
mineralization present between 500 and 1500 feet deep in the Springer mine
2. Define new mineralized zones as a result of the
geophysical compilation which will be carried out by
Frederic Gaucher within his Master in the Laurentian
University in Sudbury.
3. Continue the development of the property PROPERTY LOCATION
The Opemiska mine property is located in Chapais and is easily
accessible from Montréal via Highway 113 or from Quebec City
from Highway 167, then Highway 113 (Figure 1). CLAIMS Ex-In owns eleven claims in the vicinity of the Opemiska mine (Figure 4) which total 684,86 hectares (Table 1). Claims are 100% owned by Ex-In. Eight of the claims cover the Springer and Perry past producing mines and total 518.23 hectares. BACKGROUND – CHIBOUGAMAU-CHAPAIS MINING CAMP The Chapais-Chibougamau mining camp is the second largest
mining district in the Quebec part of the Abitibi greenstone belt.
The camp has produced approximately 86 million metric tonnes
of ore from 1953 to 2008, including 1.57 million tonnes Cu,
176.1 tonnes Au, 108.8 tonnes Ag, and 72,066 tonnes Zn
(Leclerc and al., 2012). Production at Opemiska started in 1953 and ceased in 1991.
Production tonnage was extracted from four mines, namely the
Springer, Perry, Robitaille and Cooke mines. A total of
approximately 600,000 short tons of copper, 216,000 ounces of
silver and 529,000 ounces of gold have been produced from
26.6 million short tons of milled ore.
Mineralization in the Chapais-Chibougamau area is classified into
the following types (Leclerc and al., 2012):
• Syn-magmatic Fe-Ti-V and Ni-Cu platinum group element
(PGE) mineralization in mafic-ultramafic layered complexes and
sills. Fe-Ti-V deposits occur within the Layered zone of the Lac
Doré Complex, especially where it thickens in areas of
interpreted syn-magmatic faults. Sub-economic magmatic Ni-Cu
deposits occur at the contacts of mafic-ultramafic or tonalitic
intrusions.
• Syn-magmatic “Chibougamau-type” Cu-Au veins formed
through magmatic-hydrothermal processes. They are cut by
dikes that predate regional D2 deformation but are located
within, and are deformed by, north-west and north-east rending
D2 shear zones.
• Syn-magmatic early polymetallics Au-Ag-Cu-Zn-Pb veins
associated with north/north-west to north/north-east-striking
syn-volcanic faults.
• Syn-volcanic volcanogenic massive sulfide (VMS). VMS
deposits occur within felsic volcanic rocks of tholeiitic affinity
and mafic to felsic volcanic rocks of transitional to calc-alkaline
affinity at the top of three volcanic cycles of the Roy Group.
VMS deposits are associated with north/north-west to
north/north-east-striking syn-volcanic faults.
• Shear zone hosted “orogenic” Cu-Au and Au. o “Opemiska-type” Cu-Au veins occur within regional overturned
anticlines in mafic sills of the Cummings Complex. Veins in the
Chapais area are developed in east-west reverse D2 shear zones
that parallel the axial surface of the Beaver Lake anticline in the
upper gabbro of the Ventures sill. These veins are also
reoriented into north-west/south-east D2 shear zones and
faults.
o Au deposits are developed preferentially within regional east-
west–trending deformation corridors and along north/north-
east-striking sinistral shear zones.
GEOLOGY
The Opemiska mine is located in the northeastern Abitibi
greenstone volcanic belt just west of the town of Chapais
(Figure 5). The area is underlain by Archean rocks of the
Obatogamau and Gilman Formations (pillowed basalts and
gabbro sills) and the Blondeau Formation (volcano-sedimentary
assemblage). The Blondeau Formation is intruded by the
Cummings Complex which consists of three ultramafic and mafic
sills, namely the Roberge, Ventures, and Bourbeau sills. The
Ventures sill is divided into five members, in ascending
stratigraphic order, Lower Green Pyroxenite, Black Pyroxenite,
Upper Green Pyroxenite, Foliated Gabbro, and Ventures Gabbro.
The Springer mine is located in the Ventures Gabbro.
Lithologies have been intruded by the Opemisca granitic pluton.
Lithologies are compressed and metamorphosed to the
greenschist facies (chlorite-epidote-tremolite). The northeast-
trending Gwillim fault has displaced the sequence in the order of
2.5 km. Regional and local structures are important factors controlling
the Cu-Au-Ag mineralization at Opemiska which appears to be
syn-tectonic to post-tectonic in age. Mineralization is
concentrated in networks of veins and veinlets of different
orientations with dips generally sub-vertical. Veins occur within
regional overturned anticlines in mafic sills of the Cummings
Complex. Veins are developed in east-west reverse D2 shear
zones that parallel the axial surface of the Beaver Lake anticline
in the upper gabbro of the Ventures sill. These veins are also
reoriented into north-west/south-east D2 shear zones and
faults. Vein width varies from 0.5 ft to several tens of feet. At the Springer mine the ore consists of semi-massive to
massive chalcopyrite-magnetite-quartz-carbonate ± pyrite veins
and veinlets in a subophitic gabbro (Leclerc and al, 2012). The
main metallic minerals observed are chalcopyrite, pyrite,
pyrrhotite, magnetite, and gold with minor amounts of
sphalerite (locally abundant), gersdorffite and galena (Salmon,
1984). Traces of molybdenite, cobaltite, scheelite, bornite, and
malachite are present in the mineralization. The economic
mineralization is almost entirely confined to the Ventures sill.
At the Springer mine, veins generally strike east-west while at
the Perry mine, veins strike generally north-south. The fracture
system may have developed during the regional folding.
For further details on the Opemiska property, please fulfill the
confidentiality agreement to receive the reports written by
RPA.
© Copyright 2014 - All rights reserved
Fig.3: Diamond Drilling Campaign, held in 2010
Fig.6: Prospecting campaign, held in 2002
Click thumbnail to enlarge the flyers
Table 1: Claims List
Figure 1: Location Map of the Opemiska Project Click thumbnail to enlarge
Fig.2 Diamond drilling cores from hole # OP-2010-19: 17% Cu + 1.7 g/t Au / 3m. Fig.5: Local Geology
Fig.4: Claims Map
Fig.7: 2012 Geophysical Survey: Magnetic Anomalies
Fig.8: 2012 Geophysical Survey:
Induced Polarization Anomalies
Fig.9: Interractive 3D model
of the drifts, stopes and partial
geology © Copyright 2019 - All rights reserved
SEE MORE PICTURES OF OPEMISKA Fig.10: Presentation of the
Opemiska Property (.PDF)