Aston Bay and Partner American West Metals Identify Large Significant Copper Targets at the Storm Copper Project, Nunavut
Aston Bay and Partner American West Metals Identify
Large Significant Copper Targets at the Storm Copper
Project, Nunavut
• High-resolution ground gravity survey identifies significant new anomalies that
support the potential for a large-scale sediment-hosted copper system as predicted by
geological modeling
• Strong gravity anomalies identified below and adjacent to the known near-surface
copper mineralization
• The anomalies have an upper boundary at 200 metres (m) depth, extend for several
kilometres, and are interpreted to represent dense bodies that are consistent with
copper sulfide deposits
• The outer periphery of one large gravity anomaly was intersected by a 2022 drill hole
that terminated in 68m of copper-bearing sulfide mineralization (remaining open at
depth) from 277m downhole
• Gravity anomalies are coincident with historical electromagnetic (EM) and induced
polarization (IP) anomalies indicating both dense and electrically chargeable bodies
which are interpreted to be consistent with sulfide mineralization
TORONTO, ON / June 13, 2023 / Aston Bay Holdings Ltd. (TSXV:BAY) (OTCQB:ATBHF)
("Aston Bay" or the "Company") reports on significant gravity anomalies in results from the
high-resolution ground gravity geophysical program at the Storm Copper Project ("Storm" or the
"Project") on Somerset Island, Nunavut, Canada. The program was conducted this April and
May by American West Metals Limited ("American West"), who are the project operator since
entering an option agreement with Aston Bay in March 2021.
Figure 1: Gravity data interpretation map showing the 3D gravity targets, known copper sulfide
deposits and major faults (overlaying topography).
"These are spectacular results from the gravity survey conducted at Storm this spring by our
partners American West," stated Thomas Ullrich, CEO of Aston Bay. "The anomalies are large,
with a strike length of several kilometres, and spatially coincident with the known shallow high-
grade copper mineralization. Importantly, the anomalies are relatively shallow, with an upper
boundary at about 200m depth, well within range of the diamond drill.
"The upper margin of one of the largest gravity anomalies was intersected by drill hole ST22-10
in the 2022 drill campaign. Targeting a conductivity anomaly, the hole ended in 68 metres of
sulfide mineralization. Being both dense and electrically chargeable, the sulfide is a plausible
cause for both the gravity and conductivity anomalies.
"Further, the dominantly pyrite-chalcopyrite sulfide mineralization in the intercept is the style of
mineralization found on the periphery of the high-grade copper zones elsewhere at Storm. Here
we have a drill hole intercepting peripheral-style sulfide mineralization on the margin of a very
large gravity anomaly - this is an exciting target for the summer 2023 drill program."
Figure 2: Chalcocite (with malachite alteration) is extensively exposed at surface at Storm and
suggests potential ‘leakage' sourced from a large sediment-hosted copper system below.
LARGE AND DENSE BODIES DEFINED UNDER KNOWN COPPER
MINERALIZATION
The gravity survey is interpreted to have effectively defined a series of dense features that are
spatially associated with the interpreted graben fault architecture and known copper sulfide
mineralization at Storm (Figures 3 & 4). These geological features closely adhere to the typical
sediment-hosted copper model as seen in the large copper deposits of central and southern Africa
and highlight the exceptional exploration potential of the area.
The interpretation has highlighted a series of NW-SE orientated gravity anomalies along the
main Storm graben axis, which are discontinuous and/or are offset in places due to a series of N-
S oriented faults. The anomalies appear to have higher densities where they intersect the main
graben faults, and form a series of lobes with decreasing density away from the faults (Figures 1
& 4).
Figure 3: Total bouguer gravity anomaly image and graben fault architecture, overlaying
topography. Refer to Figure 4 for locations of known surface mineralization.
The ‘northern fault' gravity anomaly extends over approximately 4.8km, is located to the north of
the main fault, and is broken into two main zones. The easternmost zone is located directly
below the 4100N Zone, where ongoing drilling has defined thick and continuous copper
mineralization in the near-surface (<100m depth) over 1km of strike.
The ‘southern fault' gravity anomaly is approximately 4km long, lies south of the graben fault,
and is bounded by the 3500N, 2750N and 2200N high-grade copper zones.
Figure 4: Interpretation of the bouguer gravity data showing the anomalies spatial relationship
to the graben faults and known near-surface copper deposits (overlaying topography)
LARGE SIGNIFICANT TARGETS MODELED BY 3D INVERSION
A 3D inversion was completed on the gravity data to produce a series of gravity contrast iso-
shells, which are designed to highlight the areas with the greatest density contrasts in 3D
(Figures 5 & 6). These could represent potential areas of stronger copper mineralization and are
high priority drill targets.
The largest of the 3D gravity targets is located along the northern fault and directly underneath
the 4100N Zone (Figures 5 & 6). The feature commences at approximately 200m depth and is
approximately 2.3km long. The gravity feature is coincident with a strong historical IP anomaly
on its upper contact. This is a highly significant association and indicates a both dense and
electrically chargeable body. The only known dense and chargeable geological feature at depth
in the Storm area are sulfides.
Several other gravity targets are also defined by the 3D inversion along the southern fault. The
data indicate that a strong gravity anomaly is located near the surface to the west of the high-
grade 2750N Copper Zone. This location also features strong EM and IP anomalies associated
with known copper mineralization in sparse, shallow historic drilling (5m @ 2% Cu and 0.8m @
20% Cu in drill hole ST00-66).
Figure 5: Geophysical summary map showing the new gravity density contrast anomalies, deep
EM conductors and strong IP (>14Mv) anomalies (overlaying drill collar locations, graben
faults and topography).
Figure 6: East-West long section showing the large density anomaly (red) underneath the 4100N
Zone mineralization. Note the strong IP anomaly (magenta) is spatially coincident with the top
of the gravity anomaly.
DRILL HOLE ST22-10 -THE EDGE OF A MAJOR COPPER SYSTEM?
Exploration drill hole ST22-10 was completed in 2022 targeting a large EM anomaly to the west
of, and at a deeper stratigraphic level than, the near-surface high-grade 4100N Zone. The EM
anomaly is located on the southern edge of a strong airborne gravity anomaly associated with the
northern graben fault.
The drill hole intersected a thick sequence of copper and zinc sulfide-bearing mineralization
hosted within carbonate sediments before being abandoned due to technical drilling issues.
Approximately 68.8m of chalcopyrite-bearing sulfide mineralization (Figure 7) was intersected
from 277m downhole (approx. 230m vertical depth), remaining open at depth. The sulfide
mineralization is interpreted to be stratabound and is hosted within a vuggy, bituminous and
fossiliferous unit.
Figure 7: Chalcopyrite (copper sulfide), pyrite (iron sulfide), sphalerite (zinc sulfide) and galena
(lead sulfide) within vuggy bituminous dolostone in ST22-10 drill core from 313m downhole.
A distinct zonation of metal associations and mineralogy is noted at the 4100N, 2750N and
2200N Zones at Storm: a large copper-rich core (chalcocite, bornite and covellite) gives way
laterally and vertically to thinner peripheral zones of copper-iron (chalcopyrite), iron (pyrite),
zinc (sphalerite) and minor lead (galena). ST22-10 intersected the peripheral mineralogical
assemblage (chalcopyrite, pyrite, sphalerite and galena) suggesting the potential for a nearby
larger, more copper-rich core.
The metal associations and zonation of the mineralization suggest that drill hole ST22-10
potentially intersected the edge of a larger copper system.
Additionally, the geology displays all the elements required in the sediment-hosted
mineralization forming process: permeable carbonate rocks to act as a fluid conduit and host
mineralization, hydrocarbons to reduce metal-bearing fluids and force metal precipitation, sulfur
source from bitumen and sour gas, proximity to faults known to be an effective source for
plumbing, all within a favourable structural setting.
These key features are similar to many of the world's major sediment-hosted copper systems,
including the deposits of the Kalahari Copper Belt (Botswana) and Central African Copper Belt
(DRC, Zambia).
The three-dimensional interpretation of the 2023 gravity data suggests that drill hole ST22-10
was drilled just to the south of, and likely intercepted the margin of, the large anomaly below
and to the west of the 4100N Zone (Figures 5 & 6).