Aston Bay Identifies Two High-Priority Drill Targets from the 2015 Gravity Surveys at Storm
Vancouver, British Columbia / TheNewswire / September 30, 2015 - Aston Bay Holdings Ltd. (TSX-V: BAY) ("Aston Bay" or the "Company") today announced that gravity surveys conducted during the 2015 field program have identified two high-priority drill targets at the Storm Copper Property, located on Somerset Island, Nunavut Territory ("Storm" or the "Storm Property").
Aston Bay collected ground gravity measurements at 987 stations on the Storm Property during the 2015 exploration season. Gravity field measurements detect variations in the local gravity field that result from density contrasts in the subsurface, such as higher density copper minerals and associated alteration minerals at a number of mineralized zones versus their host carbonate rocks, as seen at Storm. The program provided orientation surveys over areas of known mineralization and coverage of high-priority conductivity targets identified by the 2011 VTEM survey. Importantly, the gravity anomalies identified from the program are of significant size and amplitude, and are considered priorities for drill testing.
The 2015 exploration program had a number of key successes:
Blizzard Target Area (previously known as the SE Anomaly):
-The historic gravity anomaly identified by a 1999 survey (see Aston Bay news release dated May 28, 2015) in the Blizzard Target Area was confirmed and further defined.
-An additional new 0.7 (up to 0.9) mGal gravity anomaly measuring 1,200 m x 600 m was identified.
-The historic and new gravity anomalies are spatially coincident with a VTEM conductivity anomaly and a weak surface copper geochemical anomaly.
-Blizzard is considered a high priority for further geophysical work and drill testing.
Tornado Target Area (previously known as Eastern Extension):
-A new significant 1.0 (up to 2.0) mGal gravity anomaly was identified measuring 1,100 m north-south and at least 1,100 m east-west; it remains open east-west along strike.
-The Tornado gravity anomaly coincides with a VTEM conductivity anomaly and a surface copper geochemical anomaly.
-Tornado is considered to be a high priority for further geophysical work and drill testing.
Squall Target Area:
-A 0.35 mGal gravity anomaly measuring at least 900 m x 200 m was identified approximately 4.5 km west-northwest from the 4100N Zone along the same structural corridor. It is open to the east and west.
-Similar to the 4100N Zone, the anomaly is coincident with a weak surface copper geochemical anomaly, and it lies on the margin of a VTEM conductivity anomaly.
-Squall is considered a promising target and is a priority for further geophysical work.
Core Mineralized Zones Orientation Surveys:
-Gravity anomalies of 0.6 (up to 1.0) mGal and 0.2 (up to 0.4) mGal were observed at the 4100N and 3500N zones, respectively.
-Both gravity anomalies remain open along strike.
-The observed gravity anomalies are coincident with known copper mineralization in both the 4100N and 3500N zones, with a significant VTEM conductivity anomaly also present at the 4100N Zone.
-Both zones are considered a high priority for additional geophysical work and drill testing.
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"The results of the 2015 field program have exceeded our expectations, which allows us to move confidently to the drilling stage at Storm," says Benjamin J. Cox, President and CEO of Aston Bay. "In addition to the core zones of mineralization, which remain open laterally and at depth, we have defined two compelling, kilometre-scale targets for drill testing. Equally important, we confirmed that gravity is an effective exploration tool at Storm and that it will play a key role in resolving targets within Aston Bay's extensive land package."
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Gravity surveys measure local variations in the Earth's gravitational field, which can arise from density contrast associated with variations in subsurface rocks. The copper bearing minerals identified during exploration drilling include chalcocite, bornite and chalcopyrite along with other alteration minerals that have considerably higher densities than the carbonate host rocks at Storm. The expected density contrast between mineralized zones, altered zones and unaltered carbonate host rocks invites the use of gravity as an exploration tool for subsurface mapping at Storm. Furthermore, the acquisition and interpretation of gravity data will aid in the elimination of conductivity targets identified in the 2011 VTEM survey that could be the result of non copper or other base metal bearing sources such as saltwater, graphite or other false positives that can produce elevated electromagnetic responses.
Detailed Technical Information
The Blizzard and Tornado target areas were initially identified as positive conductivity targets by the 2011 VTEM survey. Similarly, the 4100N Zone was first characterized by a high conductivity anomaly with a weak coincident surface geochemical anomaly. It was the last target tested during the late 1990's and returned some of the best intercepts from the historic drill program. Furthermore, gravity surveys have the ability to identify mineralization in areas that have little to no conductivity response or contrast, such as the drill-confirmed 3500N Zone.
Exploration Target Areas
Gravity measurements were acquired over two high priority exploration targets located approximately 7 to 9 km southeast along strike from the core copper zones at Storm. The survey, which utilized a hexagonal grid pattern with station spacing equidistant at 150 m, was designed to increase confidence in the technical merit of the target areas and further define the geometry and extent of each target in order to identify optimal areas for initial drill testing. The survey was completed in the Blizzard and Tornado target areas (formerly known as the SE Anomaly and Eastern Extension, respectively).
Blizzard Target Area: The Blizzard Target Area is located approximately 9 km southeast of the core zones but along the same structural corridor that hosts copper mineralization at Storm. It was identified by the 2011 VTEM survey as a zone of elevated conductance within the Allen Bay Formation, measuring approximately 4.5 km x 2.0 km. It is also associated with a weak surface copper geochemical response. A limited gravity survey was completed in 1999 covering a portion of the target area. A gravity high of 0.3 mGal was identified coincident with part of the conductivity anomaly (see Aston Bay news release dated May 28, 2015).
The 2015 gravity survey at Blizzard validated the historic data and confirmed the presence of a modest gravity high coincident with the 1999 gravity anomaly. The new, larger survey further defined the anomaly as two 400 m x 400 m 0.2 mGal highs within a slightly elevated background (~0.1 mGal), and revealed that the quality of the anomaly may improve with depth. The anomaly is likely hosted in the lower Allen Bay Formation stratigraphy or lower.
Approximately 2.5 km northwest of the historic anomaly, a new 0.7 (up to 0.9) mGal anomaly measuring roughly 1,200 m x 600 m was identified coincident with the northeastern margin of the broad, positive conductivity anomaly identified by the 2011 VTEM survey at Blizzard. The anomaly abuts the southern bounding fault of the Central Graben within a structurally complex area, with the Allen Bay, Cape Storm and Douro formations juxtaposed surrounding a small graben feature. This compelling gravity high is considered a high priority drill target.
Tornado Target Area: The Tornado Target area is located approximately 7 km southeast of the core zones along the same structural system that hosts the known Storm copper mineralization. Tornado is defined by an approximately 4.0 km x 1.5 km positive conductivity anomaly identified by the 2011 VTEM survey with a coincident moderate to strong surface copper geochemical anomaly. The Tornado Target occurs immediately north of the 0.7-0.9 mGal anomaly in the Blizzard Target Area, on the north side of the graben feature.
The 2015 gravity survey identified a significant 1.0 (up to 2.0) mGal gravity high measuring 1,100 m across, coincident with the VTEM conductivity anomaly and surface copper geochemical anomaly at Tornado. The anomaly appears to be hosted in upper Allen Bay Formation stratigraphy, similar to the core area main copper zones, and remains open to the east and west.
Tornado is considered to be a high priority for additional geophysical coverage and drill testing due to its excellent potential for sediment-hosted copper mineralization based on geophysical and geochemical signatures coupled with its structural setting and proximity to known mineralization.
Core Copper Zones
Gravity data were collected in the core zones as an "orientation" survey in order to evaluate the gravity response associated with drill-tested copper mineralization. The 2015 surveys identified gravity responses coincident with known mineralization at Storm, providing a compelling proof of concept for the gravity method. The results of these surveys will be essential for targeting new mineralized zones during future exploration programs and for prioritizing existing targets. Surveys were completed over two of the four copper prospects at Storm: the 4100N Zone and the 3500N Zone.
4100N Zone: The 4100N Zone is the largest drill-tested mineralized zone at the Storm Property. It is located in a structurally complex area along the north bounding fault of the Central Graben structure. The zone is currently traced over 1,000 m in strike length and 400 m in width and is open to the north, east, and west, and at depth. Unlike the other core zones, the 4100N Zone was essentially a blind target, displaying a limited geochemical response at surface. It was instead targeted by a series of geophysical surveys during historic exploration. The 4100N Zone is characterized by a strong positive conductivity response in the 2011 VTEM survey. Historic drilling reported intersections of up to 1.83% Cu over 28.0 m core length (ST00-62) and 3.75% Cu over 15.7 m core length (ST99-47). Mineralization typically occurs in breccias, veins or as replacements, and the copper mineralogy is dominated by high-copper species including chalcocite and bornite.
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Three gravity profiles separated by 100 m were completed over the 4100N Zone at a station spacing of 25 m. A pronounced 0.6 (up to 1.0) mGal gravity high was observed spatially coincident with the known copper mineralization and positive conductivity anomaly detected in the 2011 VTEM survey. The gravity high measures a minimum of 600 m north to south and is open to the east and west beyond the extent of the orientation survey. As with the VTEM survey, the 2015 gravity survey at the 4100N Zone suggests the potential for mineralization beyond the depth of drilling to date.
3500N Zone: The 3500N Zone is characterized by a strong geochemical response at surface, and long drill intersections of lower-grade mineralization in previous exploration, including up to 1.23% Cu over 55.1 m core length (ST99-31) and 0.74% Cu over 50.8 m core length (ST99-43). The copper mineralization occurs within a complex of intersecting faults, located along the south bounding fault of the Central Graben, and is of a similar style to the mineralization at the 4100N Zone. Unlike the other drill-confirmed zones, the 3500N Zone did not show a strong conductivity response in the 2011 VTEM survey.
Gravity data were collected along three orientation lines spaced 100 m apart at a station spacing of 50 m. The 3 km orientation lines covered the known mineralization at 3500N and a significant cross-section of the Central Graben structure. A 0.2 (up to 0.4) mGal gravity high was observed, broadly correlating with the known mineralization. The survey also identified a second, 0.35 mGal gravity high (the Squall Target Area) 4.5 km west-northwest along strike from the 4100N Zone, straddling the north bounding fault of the Central Graben.
The 3500N Zone orientation survey highlights the success of the gravity method in identifying mineralization where little to no conductivity response is observed and illustrates the importance of a structured, multi-technique approach to exploration at Storm.
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The 2015 gravity surveys at Storm identified two high priority drill targets and a number of secondary targets for follow-up exploration. Aston Bay's 2016 exploration program is in the early planning stages but is anticipated to include:
-Additional modelling of the 2011 VTEM data over the known mineralized zones in the core area.
-A spring geophysics program to extend the gravity grid at Blizzard and Tornado and to cover the known mineralized zones in the Central Graben area. Select areas are planned to be targeted with ground time domain electromagnetic surveys (TEM) to enhance targeting of exploration drilling.
-A relog program of historic drilling to develop a geological model and to further constrain the controls on mineralization in the core copper zones.
-A summer drill program to provide initial testing of the new targets identified to date and further testing of select zones in the core area.
The content of this news release and the technical information that forms the basis for this disclosure has been prepared under the supervision of Michael Dufresne, M.Sc., P.Geol., who is the Qualified Person as defined by NI 43-101 and a consultant to Aston Bay.
About Aston Bay Holdings
Aston Bay Holdings Ltd. (TSX-V: BAY) is a publicly traded mineral exploration company focused on the 641,415-acre (259,570 hectares) Aston Bay Property located on northwest Somerset Island, Nunavut. The Property hosts the Storm Copper and Seal Zinc prospects, where historic drilling has confirmed the presence of sediment-hosted copper and zinc mineralization. Aston Bay holds the right to earn or buy up to a 100% undivided interest in the Storm Property from Commander Resources Ltd. (TSX-V: CMD).
On behalf of the Board of Directors,
Benjamin Cox, Chief Executive Officer
Telephone: (360) 262-6969
For further information about Aston Bay Holdings Ltd. or this news release, please visit our website at www.astonbayholdings.com.
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