- The greenfields Gregors copper discovery was made by drill-testing a buried VTEM geophysical anomaly which is coincident with an outcrop of breccia and gossan
drilling at Gregors intersected a blind zone of disseminated copper sulphide
- GGC-002: 6.0m @ 2.30% Cu within a wider zone of 30m @ 0.68% Cu from 22.5m
- GGC-003: 1.5m @ 7.03% Cu within a wider zone of 18m @ 0.96% Cu from 21.0m
- A single hole drilled at the old San Simon
mine intersected a wide zone of strong gold mineralisation:
- MDPC-168: 21m @ 2.0g/t Au & 64g/t Ag from 19.5m; including 6.0m @ 3.35g/t Au
Azure Minerals Limited (“Azure” or “the Company) (ASX: AZS) is pleased to announce that drilling at its 100%-owned Alacrán Project in Sonora, Mexico, has successfully discovered high-grade copper mineralisation at the Gregors prospect and intersected further significant gold mineralisation at Mina San Simon.
Azure’s Managing Director, Tony Rovira, said: “Our exploration team has a strong and successful history of discovering new deposits at Alacrán. With this discovery of the buried copper mineralisation at Gregors, we are continuing to identify high-value precious and base metals targets, reinforcing the prospectivity of this exciting project and the technical skills of our exploration team.
“The discovery of strong copper mineralisation hosted by iron-rich breccia at Gregors is very promising, as there is a history of discovering and exploiting high-grade, copper-rich breccia pipes in the surrounding Cananea mining district, particularly at the nearby Cananea Copper Mine located 10km to the northwest. I’m looking forward to completing our interpretation of the results and recommencing drilling as soon as practicable.”
The Gregors prospect was originally recognised by Azure’s geologists in early 2016 when mapping identified breccia and gossan outcropping over an area of approximately 100m x 100m. The strongly iron-rich breccia and boxwork texture within the gossan suggested a sulphide-rich source, potentially representing base metal mineralisation. However, geochemical sampling of the outcrop returned only low grades of precious and base metals, downgrading the priority of the prospect at that time.
In late 2016, Azure flew an airborne VTEM geophysical survey over the entire Alacrán project area, and a small and discrete, reasonably intense electromagnetic (EM) response was detected coincident with the gossan outcrop. Modelling indicated the presence of a steep east-dipping EM conductor plate located beneath the gossan outcrop.
No further exploration was undertaken over this anomaly until late in 2019, when Azure regained full ownership and control of the Alacrán project from former partner Teck Resources. Detailed mapping, surface geochemical sampling and a ground EM survey were carried out over the gossan and the area of the VTEM anomaly in early 2020. This identified faults and shearing and strong alteration within and around the gossan, and sampling returned weakly anomalous copper grades.
Four angled RC drill holes were drilled to test both the EM anomaly and beneath the gossan. Two holes (GGC-002 & GGC-003) were drilled from the same collar position with different dip angles. Both holes intersected wide zones of breccia and strongly altered volcanic rocks containing significant visual quantities of disseminated chalcopyrite (copper sulphide) mineralisation, returning the following intersections:
- GGC-002: 30m @ 0.68% Cu from 22.5m; including 6.0m @ 2.30% Cu
- GGC-003: 18m @ 0.96% Cu from 21.0m; including 1.5m @ 7.03% Cu
The other two holes (GGC-001 & GGC-004) intersected altered and brecciated rocks containing disseminated pyrite, pyrite in veins and minor amounts of disseminated chalcopyrite that returned anomalous copper grades.
The Company’s current interpretation is that GGC-002 & GGC-003 intersected a higher-grade, copper-rich core potentially representing a mineralised breccia pipe and GGC-001 & GGC-004 drilled a lower-grade halo.
The presence of strong copper mineralisation hosted by iron-rich breccia is very promising as numerous high-grade, copper-rich breccia pipes associated with nearby copper porphyry bodies have been discovered and mined in the Cananea mining district. For example, the La Colorada breccia pipe (approximately 5Mt @ 7% Cu) was mined up to the 1930s, and the Maria breccia pipe (ore reserves of 1.6Mt @ 6% Cu) was discovered in 1979 and mined up to the 1990s. At the top of these breccia pipes the cross-sectional area is usually less than 100m x 100m and the mineralised bodies often extend to very significant depths (in the hundreds of metres).
Azure is undertaking a detailed data review and interpretation plus initial mineralogical and metallurgical studies to assess potential and assist with planning a follow-up drill program.
MINA SAN SIMON DRILLING
One RC hole (MDPC-168) was drilled to test at the historical Mina San Simon mine located about 700m southeast of the southern Loma Bonita resource boundary. The area between Loma Bonita and Mina San Simon and in the vicinity of Mina San Simon is mostly untested by drilling.
The old workings comprise two horizontal tunnels and a 30m deep vertical shaft which exploited a zone of vuggy silica hosting gold and silver mineralisation. A hole drilled by Azure in 2015 (LM-02) intersected a void created by the old mine workings that had extracted the mineralised zone.
However, MDPC-168 drilled below these old mine workings and returned a well-mineralised gold and silver intersection, hosted in vuggy and massive silica, of:
- MDPC-168: 21.0m @ 2.00g/t Au & 64g/t Ag from 19.5m
Further drilling to test the vuggy silica mineralised zone, which is interpreted to extend further to the east and south beneath the Cerro San Simon hill, will be undertaken in the next drill program.
DRILL PROGRAM DETAILS
The Reverse Circulation (RC) drilling program was undertaken at the Loma Bonita gold-silver deposit for resource infill and extension, at the Mesa de Plata silver deposit to collect additional samples for advanced metallurgical testwork, and at the Cerro San Simon, Mina San Simon and Gregors greenfields exploration targets.
A total of 36 holes (MDPC-138 to MDPC-169 & GGC-001 to GGC-004) were drilled for 3,604 metres. Gold, silver and base metal assays have been received for all holes and all significant intersections are listed in Table 1. Location details for all holes are contained in Table 2.
Drilling has now been completed and the drill rig demobilised.
Figure 1: General location plan for the Alacrán Project showing operating mines in the district
Figure 2: Plan of the Alacrán Project with drill holes
Figure 3: Mesa de Plata and Loma Bonita mineral resources and nearby drill hole locations
Figure 4: Drill holes at Gregors
Figure 5: Drone photo of outcropping gossan at Gregors, looking northwest
Figure 6: Drone photo of drilling at Gregors, looking southeast
Figure 7: Photos of RC drill cuttings from Gregors with mineralised copper intersections Drill hole GGC-002 on the left and GGC-003 on the right
TABLE 1: Gold mineralised drill intersections for holes MDPC-138 to MDPC-169.
Mineralised intersections use a 0.2g/t Au grade cut-off; included zones use a 1.0g/t Au cut-off. Intersections use maximum internal dilution of 1.5m (**note** uses max 3.0m internal dilution).
Table 2: Location data for holes MDPC-138 to MDPC-169
Authorised by: Brett Dickson Company Secretary.
For enquiries, please contact:
Azure Minerals Limited
Ph: +61 8 9481 2555
|Media & Investor Relations|
Michael Weir/Cameron Gilenko
Ph: +61 8 6160 4903
or visit www.azureminerals.com.au
Competent Person Statements:
Information in this report that relates to Exploration Results for the Alacrán Project is based on information compiled by Mr Tony Rovira, who is a Member of The Australasian Institute of Mining and Metallurgy and fairly represents this information. Mr Rovira has sufficient experience relevant to the style of mineralisation and type of deposit under consideration, and to the activities undertaken, to qualify as a Competent Person as defined in the 2012 Edition of the Joint Ore Reserves Committee (JORC) Australasian Code for Reporting of Exploration Results, Mineral Resources and Ore Reserves. Mr Rovira is a full-time employee and Managing Director of Azure Minerals Limited and consents to the inclusion in the report of the matters based on his information in the form and context in which it appears.
Information in this report that relates to Mineral Resources for the Alacrán Project is extracted from the reports “Silver Resource Upgraded at Mesa de Plata” created and released to the ASX on 1 December 2016 and “Initial Mineral Resource Estimate for Loma Bonita” created and released to the ASX on 21 December 2016 and are available to view on www.asx.com.au. Azure Minerals Limited confirms that it is not aware of any new information or data that materially affects information included in the relevant market announcement, and that all material assumptions and technical parameters underpinning the estimates in the announcement continue to apply and have not materially changed.
Original Article: https://azureminerals.com.au/wp-content/uploads/2020/03/200323.pdf