During the early summer of 2022, Quantec Geoscience had been contracted by Viscount mining to perform a five-line TITAN MT survey over the Silver Cliff caldera of the Passiflora target. The goal of the survey was the identification of conductive areas below the survey surface which could potentially represent metal deposits or the presence of porphyry.
Quantec is authorized by the Association of Professional Geoscientists of Ontario (PGO). Its roster of clients includes Newmont Mining, Barrick Gold, Agnico-Eagle Mining, De Beers Consolidated Mines Limited, and the Nevada Department of Energy amongst others.
For the current project, each of the 5 parallel lines surveyed by Quantec were 2.2 kilometers (1.36 miles) in length and separated by 175 meters (574 feet). Ground-penetrating resistivity data was gathered overnight from each survey line. This data was analyzed and converted into cross sections.
TITAN MT survey identified extremely low resistivity zone
In their executive summary, Quantec declared that: “The TITAN MT survey identified a zone of extremely low resistivity in the Silver Cliff caldera. The main anomaly is bowl-shaped and at a depth of ~450m (~1475 ft) at the point nearest to the surface below lines L1E and L2E…
The 2D and 3D modeled depth of the anomaly extends ~1500m (~4920 ft) deep, or to an elevation of ~900m (~2950 ft), but the source could be deeper. The extreme conductivity of the anomaly and sensitivity of the MT method limit resolution of the inversion result below the massive conductive zone.”
Viscount CEO Jim MacKenzie commented, “In response to these extraordinary findings, Viscount is currently putting together a drill program aimed at determining the composition of the very high conductivity source. Quantec Geoscience stated this is one of the lowest resistivity anomalies they have ever seen. The Quantec survey shows that the geophysical foot print has the indication that we are looking at a potentially significantly large mineral system at the Passiflora.”
Talking about the structure of the anomaly, Quantec added: “there are branches oriented in a roughly E-W direction that come closer to the surface to ~320m (~1050 ft) depth below lines L4E and L5E in the south-eastern part of the grid. These branches could be related to fault-controlled mineralization or alteration.”
The only historic report about the Passiflora target was written by R. A. Rivera for Coca Mines in 1983. In this report, Rivera outlined a brief history of exploration efforts in the area and had inferred a potential deposit size of 40 million tons of AgEq in the form of silver, gold, lead, and zinc (not NI 43-101 compliant).
This report stated that the deposit was presented as “a set of steeply dipping, NNW striking, tabular mineralized zones” (Rivera, 1983). It was also implied that the deposit could possibly go much deeper as Rivera had highlighted that some drill holes presented high assay values at their total depths.
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Viscount mining has drilled six drill holes throughout the Passiflora target. The deepest of these goes 215m (705 ft) below the surface. Evident phyllic alteration and associated metal concentration increases were observed throughout the entire drilled depth in each of the six holes.
Viscount Mining was inclined to further explore the probability of the Passiflora target presenting as porphyry at depth because of the level of increased alteration displayed along with the volcanic history of the region as a caldera.
Jacob Hooker, Silver Cliff Exploration Manager emphasized that: “This caldera is one of at least ten eruptive centers of the Central Colorado Volcanic Field (CCVF). Four of these ten have been further classified as silicic eruptive centers, of which the Silver Cliff caldera is one (McIntosh and Chapin, 2004).
Another classification member is Newmont’s Cripple Creek Mine, a highly profitable, still active deposit located ~70km NNE of the Passiflora. The ore being mined at Cripple Creek is primarily from diatremes (volcanic breccia pipes), which overlie sulfide-altered, porphyritic igneous intrusions. A similar system of diatremes and sulfide-hosting igneous intrusions may also exist at depth in the Passiflora target.”
The Silver Cliff property in Colorado is located within the historic Hardscrabble Silver District in the Wet Mountain Valley of Custer County (south-central Colorado). It is located 44 miles WSW of Pueblo, Colorado and comprises of 96 lode claims where high grade silver, gold, and base metal production came from numerous mines from 1878 to the early 1900s.
The property also underwent substantial exploration between 1967 and 1984 and is interpreted to encompass a portion of a large caldera and highly altered sequence of tertiary rhyolitic flows and fragmental units which offers potential to host deposits with both precious and base metals. This has been demonstrated in the mineralization historically extracted from the numerous underground and surface mining operations.
Based on the accumulated data and feasibility study, Tenneco Minerals had made the decision, with silver at $5 USD an ounce, to construct a $35,000,000 USD milling operation for the extraction of the silver reserves at Silver Cliff at that time. Soon afterwards, Tenneco’s Mining Unit was sold, and the planned milling operation was abandoned.
Apart from Silver Cliff, Viscount Mining’s portfolio of silver and gold properties in the Western United States also includes Cherry Creek in Nevada. The Cherry Creek exploration property is located approximately 50 miles north of the town of Ely in White Pine County. It consists of 578 unpatented and 17 patented claims as well as mill rights.
Cherry Creek includes more than 20 past producing mines. In January 2021, Viscount entered an exploration earn-in agreement with a wholly owned subsidiary of Centerra Gold Inc. The latter is a Canadian-based gold mining company focused on operating, developing, exploring and acquiring gold properties in North America, Asia, and other markets worldwide.