Silver Cliff is thought to overlie a large caldera and porphyry system which increases the prospect’s potential to host a number of deposits from both precious metals to base metals. This has been demonstrated in the mineralogy and grade historically extracted from numerous underground mining operations dating back to the late 1800s and early 1900s.
Currently converting 100mm plus ozs of an historic silver resource at Silver Cliff, Colorado with a revised NI43 101 in early 2023 with significant exploration upside.
NI 43 101 Compliant Resource April 2023
- Indicated : 71 g/t Ag for 10,275M oz Silver.
- Inferred : 52 g/t Ag for 14,215M oz Silver.
Multiple exploration targets have been delineated for drilling.
Figure 1. An aerial image showing locations of the five TITAN MT survey lines positioned over the Silver Cliff caldera.
Ground-penetrating resistivity data gathered overnight from each of the survey lines was analyzed and converted by Quantec-employed qualified professionals into cross sections. In their executive summary, Quantec Geoscience describes their findings, saying: “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.”
Figure 2, below, is a cross section of through line L1E which depicts a view of the massive, low resistivity anomaly described by Quantec. As shown, the bowl-shaped anomaly extends ~1400m (~4590 ft) across the center of the caldera, and at least 1500m (~4920 ft) deep, maybe deeper, depending upon the accuracy of resistivity detection below the conductive body.
Figure 2. A cross section through line L1E showing resistivity (in ohm-m) to a depth of ~2400 meters (~7975 feet) below the surface.
Jim MacKenzie, Viscount CEO 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.”
Quantec also commented on the structure of the anomaly, saying: “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.” Figure 3 illustrates these branches that extend closer to the surface in an overhead, 3D view of the highly conductive deposit.
Figure 3. A view of the 3D model of the large region of low-resistivity (<2 ohm-m) inside the Silver Cliff caldera.
The only historic report available on the Passiflora target is one written by R. A. Rivera for Coca Mines in 1983. In this report, Rivera gives a brief history of the exploration efforts, inferring a potential deposit size of 40 million tons of AgEq in the form of silver, gold, lead, and zinc (not NI 43-101 compliant). It is noted in his report that the deposit was presented as “a set of steeply dipping, NNW striking, tabular mineralized zones” (Rivera, 1983). It is also implied that the deposit could go much deeper as Rivera states that some drill holes presented high assay values at their total depths.
Viscount has drilled a total of six drill holes throughout the Passiflora target, with the deepest hole going 215m (705 ft) below the surface. In each of the six holes, evident phyllic alteration and associated metal concentration increases were observed throughout the entire drilled depth. The level of increased alteration displayed, as well as the volcanic history of the region as a caldera, prompted Viscount Mining to further explore the probability of the Passiflora target presenting as a porphyry at depth.
Jacob Hooker, Silver Cliff Exploration Manager noted, “The volcanic history of the region as a caldera makes it completely reasonable to assume that the Passiflora target could be a porphyry at depth. 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 member of this classification 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.”
Silver Cliff hosts a large economical silver resource with several mineralized deposits and significant exploration upside.
The primary deposit, Kate Silver Resource (KSR), hosts a historical (non-compliant) estimate of 50M oz Silver by Tenneco Minerals in 1990. (not 43101 compliant)
Tenneco Minerals made the decision based on the accumulated data and a feasibility study with silver at $5.00 USD an ounce to construct at that time a $35,000,000 USD milling operation for open pit mining of silver reserves at Silver Cliff. Known historical silver grades range from below detection to a high of 2,125 g/t (68 o/t) Ag over 13.4 metres. Known historical gold grades range from below detection to a high of 9.06 g/t (0.29 o/t) Au over 1.2 metres. Shortly thereafter, their parent company was sold and the new owners decided to divest their mineral interests and the decision was reversed in 1991.
Approximately 1.2 kilometers NNW of the Kate Silver Resource lies a geochemically distinct, yet likely hydrothermally related deposit historically referred to as the Passiflora Deposit. According to a mining report by R. A. Rivera (1983), nearly 18,000 tons of silver valuing over $500,000 was extracted from the Herman-Passiflora Mine between 1916 and 1948. A major shaft collapse in 1945 left notable ore unrecovered (Joseph M. Bradley, 1948). A reserve calculation by CoCa Resources for the Passiflora target released in 1983 indicated at least 64M oz. silver at 51.9 G/T (not NI 43-101 compliant) stating, “a sustained advance in silver price to the $15 level would make the deposit quite attractive (R. A. Rivera, 1983).” With the price of silver now well over this mark, Viscount has begun to further develop an understanding of the Passiflora target.
Silver Cliff Property Geology
The fall of 2016 drilling shows that the silver mineralization (blue grey) is hosted predominantly by a gently-dipping unit of highly altered rhyolite tuff that was deposited during volcanic activity in the Silver Cliff caldera.The Kate Silver Resource (the “KSR”) at this juncture appears to be the result of extensive alteration by hot hydrothermal silver/lead/zinc-bearing fluids that ascended up along deep seated faults and related fractures. These rhyolite tuff units can be found over a large lateral extent are susceptible to extensive alteration by metal rich hydrothermal solutions and maybe the greatest promise for the KSR in the other deeper unexplored stacked horizons. These may be found associated with high grade epithermal veins that could underlie the KSR.
The geology shows that the silver mineralization (blue-grey mineralization) is hosted predominantly by a gently-dipping, silicified carbonate reef that formed during a volcanic hiatus. The Kate Silver Resource at this juncture appears to be the result of simple carbonate replacement by silica-rich, silver/lead/zinc-bearing fluids adjacent to interpreted deep seated epithermal veins. These carbonate rock systems replaced by silicification-associated resources are commonly found over large lateral extents and the greatest promise for the Kate Silver Resource may eventually lie in undiscovered stacked horizons, in combination with high-grade epithermal veins that may underlie the Kate Silver Resource.
At the Passiflora the level of increased alteration displayed, as well as the assumed volcanic history of the region as a caldera, make it completely plausible to believe that the Passiflora target could be a porphyry at depth. There are evidence that point to a possible porphyry system at depth The increase in the intensity of the phyllic alteration towards the South West as well as the increase in metals concentrations. Silvercliff caldera are one of at least ten eruptive centers of the central Colorado volcanic field. It has been classified as part of the silicic centers that includes Cripple creek McIntosh and Chapin NMBMMR Bulletin 160) where Mo, Au porphyry has been found at depth. The ore being mined are from diatremes (volcanic breccia pipes) within the Cripple Creek volcanic field. Diatremes may also exist at depth in the Passiflora target. Viscount management are currently considering a telluro-magnetic Survey to more precisely delineating targets at depth.
SILVER CLIFF 2016 & 2017 DRILL RESULTS
Bonanza-grade drill intercepts found near surface (< 15m)
The focus of Viscount Mining’s third phase of drilling was to test the outer boundaries of the Kate Silver Resource (KSR) as defined in Dr. Gilles Arseneau’s NI43-101 in 2018. Five of these nine drill holes lie to the northeast of the previous KSR and should significantly expand the silver resource in this direction. Specifically, drill hole 21-16, which lies approximately 120 meters outside of the previous mineralized body definition, revealed 88.8 g/t silver over 16.2 meters including 8.5 meters testing at 162.1 G/T silver. In all, these five step out drill holes in the northeast Kate cover a surface area of over 12,500 square meters and successfully expand the footprint of mineralization outside of the KSR. All holes contain sections testing above the current cut-off grade (~20 G/T). In addition to northeast expansion, the drilling also revealed slight expansion to the south. Drill holes 21-11 and 21-12 both contain sections testing over 124 G/T and are positioned up to 25 meters outside of the KSR boundary. The report titled Mineral Resource Estimate for the Silver Cliff Property, Custer County, Colorado, USA dated April 15, 2018 was prepared by Dr. Gilles Arseneau, Ph.D., P. Geo of Arseneau Consulting Services (“ACS”) in accordance with the Canadian Institute of Mining, Metallurgy and Petroleum (“CIM”) Definition Standards incorporated by reference in National Instrument 43-101 (“NI 43-101”) for its Silver Cliff property in Colorado.
Using historic drilling data and recent soil sample results, drill hole locations were selected outside of the KSR boundary, primarily to the northeast and south. Viscount is pleased to announce that the third phase step out drill holes exhibited results above cut-off grades. As shown in the map below, this now accounts for nine drill holes drilled outside of the KSR.
ROCK CHIP RESULTS 2013- 2021
Highlighted results include:
• 28 samples assaying over 100 g/t silver
• 18 samples assaying over 200 g/t silver
• 4 samples assaying over 550 g/t silver including 1330 g/t and 737 g/t in the northern Kate area and 692 g/t and 560 g/t in the south Passiflora area.
Phase 3 of Viscount Mining’s Silver Cliff drill program consisting of 13 holes over 881 meters has recently concluded and all of the core samples have been shipped and are currently being assayed. As a supplemental part of Viscount’s phase 3 drilling program, 50 surface rock chip samples were collected around the Kate Deposit, Passiflora and surrounding areas. Most of these samples were gathered from century-year-old, shallow mining pits which are found scattered throughout the Silver Cliff region. A map depicting silver concentration of each of these 124 surface samples including 74 local rock chip samples collected back in 2013 is shown below.
Twenty eight (28) of these rock chip samples collected at the surface tested over 100 g/t silver, with the highest testing sample assayed 1330 g/t silver. The presence of such high-grade silver deposits being revealed at the surface by shallow, abandoned pits, shows high promise for an eventual open pit mine. Many of these higher testing samples were collected from two locations: the southwest Passiflora and the northern area of the Kate Deposit and extension.
In the northern area of the Kate Deposit, 15 surface rock chip samples assayed between 71 and 1330 g/t silver, well above the current economic cut-off grade. Seven (7) of these high-grade rock chip samples, including the two highest testing (737 and 1330 G/T), on land outside of the current extent of the ore body as defined by Dr. Gilles Arseneau in 2018. The report titled Mineral Resource Estimate for the Silver Cliff Property, Custer County, Colorado, USA dated April 15, 2018 was prepared by Dr. Gilles Arseneau, Ph.D., P. Geo of Arseneau Consulting Services (“ACS”) in accordance with the Canadian Institute of Mining, Metallurgy and Petroleum (“CIM”) Definition Standards incorporated by reference in National Instrument 43-101 (“NI 43-101”) for its Silver Cliff property in Colorado.
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