Sascha-Marcelina
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Property Type
LSE Gold Silver Project
Size
30,600 ha
Status
Self-funded Exploration
Exploration Stage
Maiden 2,814m drill program completed in 2021 at Pellegrini, Estancia and Igloo Trends
4,333m drill program at the Sascha Main zone completed during previous JV (2006 - 2009)
Geological mapping, rock chip sampling, IP geophysics and soil grid samplingLocation
- Jurassic age volcanic rocks of the Deseado Massif in north-central Santa Cruz province, Argentina.
- Low altitude - 1,000 meters ASL
Ownership
- 24,900 ha 100% owned by Mirasol,
- 5,700 ha controlled by Mirasol under an option to purchase agreement
Sascha Marcelina is a 30,600 ha LSE gold-silver property located at the north-central part of Santa Cruz in Argentina. The project is conveniently accessible to the provincial road, Ruta 39, and with potential trucking distance of the multiple mine facilities.
The project is located 100 km south of Newmont’s Cerro Negro mine and displays similar geologic and geomorphic settings. Anomalous rock chip Au+Ag assays and Aster satellite alteration anomalies have defined a large-scale, zoned alteration system characteristic of an LSE Au+Ag system. Multiple, multi-kilometre long, mineralized vein and silicified breccia trends have been recognized across the project.
Option to Purchase Agreement - Property Claim Consolidation
In early 2019, Mirasol consolidated the large prospective Sascha-Marcelina property by signing an option to purchase agreement for the 5,700 ha from a privately-owned mining company.
Mirasol can acquire 100% of the 5,700 ha claims by making staged option payments totalling US$3.4 million over four years, with US$3.15 million due on the 4th anniversary. If the option is exercised, the Marcelina claims will be subject to a 1.5% NSR royalty. There is a minimum US$300,000 exploration spending commitment by Mirasol during the first three years of the option period.
2021
Mirasol completed a 2,814m drill program in Q2 2021. The program was focused on quality targets at the Estancia, Pellegrini and Igloo prospects, which are characterized by coincident large-scale outcropping alteration, anomalous rock chip geochemistry and Induced Polarization (“IP”) geophysical anomalies. These prospects had not previously been drilled tested (see news release August 9, 2021)
- Pellegrini Trend:
At the Pellegrini Trend, four diamond drill holes were completed at the main target area with two scout holes outboard on two other major northwest trending faults structures to the west and north, for a combined total of 1,431m.
Figure 2: Pellegrini plan view
Holes PEL-DDH-001, PEL-DDH-002 and PEL-DDH-005 were drilled at the Pellegrini main target zone located on the top of a prominent hill, resulting in an 80-100m elevation difference between the hill and the nearby topographic flats. They all encountered within their upper levels, restricted zones of anomalous mineralization associated with hydrothermal brecciation. Hole PEL-DDH-005, which was drilled deeper below PEL-DDH-002, exhibits the best mineralized intersection to date. A wide zone of peripheral crackle brecciation starts at 170m vertically below surface and continues into an inner core of hydrothermal polymictic brecciation for a total intercepted width of brecciation >25m. This inner zone returned an intersection of 20.4m at 0.24 g/t Au and 39 g/t Ag (58 g/t AgEq[1]) from 242.5m, including 10.5m at 0.28 g/t Au and 66 g/t Ag (87 g/t AgEq) from 249m. High Zn and Pb base metal results are also associated with this brecciated body with 0.82% Pb and 0.7% Zn over the broader 20.4m interval, including 1.3m with 3.19% Pb and 2.56% Zn.
Figure 3: Pellegrini section view on PEL-DDH-001 / PEL-DDH-002 / PEL-DDH-005
Photo 1: PEL-DDH-005 – Diamond core photo 247m to 263m
These results from PEL-DDH-005 are considered very encouraging as they represent a clear downward vector for the mineralization underneath the narrower, mineralized zones intersected in each of holes PEL-DDH-001 and PEL-DDH-002. Based on several geological observations, including the “peripheral” crackle brecciation, mineralization style and silica species, this intersection is interpreted to represent the peripheral or the upper part of an untested larger body of mineralization. Further drilling is required to confirm the geometry of this mineralized hydrothermal breccia body and how it relates to the local topography.
Mineralization is associated with a multi-pulse hydrothermal event resulting in a large zone of brecciation hosting at least three distinct phases of mineralization. The earliest phase is a pyrite rich, poorly mineralized pulse, followed by Ag-Pb-Zn metal rich event. The final stage is a more typical low sulfidation epithermal silica pulse and is recognized as the Au rich event. The broad zones of brecciation in drill hole PEL-DDH-05 are hosted in pyroclastic volcanics and appear to be spatially related with the margin of a large rhyolitic dome complex, as is typical in several of the productive mineralized Au/Ag systems in the Santa Cruz province of Argentina.
The widespread high resistivity anomaly present at Pellegrini also correlates well to the dome complex and related highly siliceous outflows mapped on surface. The innermost central “reduced” resistivity response corresponds with the mineralized hydrothermal brecciation, which is interpreted to be located along the outer limits of the dome margins in contact with pyroclastic volcanics. This reduced resistivity feature may represent the outline of the “top” of a larger mineralized breccia body, which has less pervasive silica compared to that of the surrounding host rocks.
As a follow-up, Mirasol is in the planning stages for a second complementary and deeper penetrating induced polarization (“IP”) geophysics program to more accurately map the location and orientation of this apparent northwest trending, northeast dipping sulfide-rich breccia.
- Estancia Trend:
At the Estancia Trend, six holes (1,011m) were completed. Three of these holes located in the southern part of the prospect (Estancia Sur) returned anomalous Au results. This drilling demonstrated that Estancia Sur is located in the lower part of the Matilda formation or upper part of the Chon Aike, neither of which are good, competent host rocks for productive fissure veins. Instead of concentrating mineralization, their physical characteristics allow for wider intersections of lower grade and dispersed mineralization, as illustrated by the results from drill hole EST-DDH-003 (8.7m at 0.32 g/t Au). However, with focused, deeper drilling, it is considered likely that a stronger mineralization could be encountered in the more permissive rock type (mid to lower Chon Aike formation).
Mineralization encountered to date at Estancia Sur occurs as narrow sheeted veinlets, pseudo-stockworks zones and fluidized channels with crackle brecciation, infilled with two styles of mineralization with an initial pulse of massive pyrite with dark grey silica and a second pulse of more epithermal crypto-crystalline quartz hosting the higher Au grades.
Figure 4: Estancia plan view and section on EST-DDH-003
- Igloo Trend:
At the Igloo Trend, limited initial drilling intercepted mineralization very similar to that of Estancia Sur, related to narrow veinlets, zones of pseudo-stockwork and fluidized channels hosting brecciation, with Au grades up to 0.57 g/t. This mineralization is associated with a pronounced and widespread “cloud” of pathfinder elements characterised by arsenic, antimony and mercury + barium. Such zones of anomalous pathfinder elements typically reside above productive systems in several low sulfidation Au-Ag epithermal mines and deposits in Santa Cruz and provide a strong vector to depth for stronger mineralization.
Figure 5: Igloo plan view and section on IGL-DDH-002
2019/2020
In 2019, Mirasol signed an option to purchase agreement for 5,700 ha claims from a privately-owned mining company and consolidated the large prospective Sascha-Marcelina property under one company for the first time.
Following this consolidation, Mirasol completed an integrated interpretation of district-scale exploration data sets collected prior to 2009. Anomalous rock chip Au+Ag assays and Aster satellite alteration anomalies define a 16.5 x 4.0 km (65 km2) “footprint” to the district, showing a large-scale, zoned alteration system characteristic of a large LSE Au+Ag system. Five, multi-kilometre long, mineralized vein and silicified breccia trends have been recognized to date across the consolidated district. The trends traverse the Pellegrini Silica Cap, or outcrop through post-mineral gravel and basalt cover that surrounds the Silica Cap.
The geologic and geomorphic setting of the Pellegrini Silica Cap and related silica structures and veins is analogous to the setting of the Cerro Negro Mine, which is a high grade, low-cost underground mine operated by Newmont and located approximately 100 km to the north of the Sascha-Marcelina project.
Interpretation of mapped volcanic and sedimentary stratigraphy, Au+Ag and multi-element geochemistry and alteration mineralogy shows that different levels of the epithermal system outcrop across the district, exposing what are interpreted to be different levels of the mineralized column of an LSE Au+Ag system.
The surface exploration activities completed on the Sascha-Marcelina project (see news release July 18, 2019) include geological mapping aided by the acquisition of drone supported high-resolution base images, detailed rock chip sampling, extensive soil grid sampling (with PXRF sourced geochemistry) and the acquisition of alteration data using in-house handheld ASD (Analytical Spectral Devices) technology on all of the rock chips and soil samples collected to date. New prospects were recognized, with the “Estancia trend” and the “Igloo trend”, both located in close proximity to an extensive Pellegrini Silica Cap, which is interpreted as representing the preserved fossil paleosurface of a low sulfidation system.
A total of 422 new rock chip samples have been collected from within the Marcelina area with assays averaging 0.25 g/t Au and 2.46 g/t Ag and up to 27.7g/t Au and 121g/t Ag, taken from epithermal silica vein/veinlets and silica-hematite hydrothermal breccias. These precious metal values are accompanied by highly elevated epithermal pathfinder elements including arsenic, antimony, tellurium, and anomalous lead and zinc.
BEFORE 2009
Mirasol staked the Sascha Project in 2003 to secure the 5 km long Sascha Vein Zone, which was partially drill tested on the western end while under an exploration agreement to Coeur Mining (“Coeur”) from 2006 to 2009. Coeur terminated the agreement in 2009 and returned 100% of the project to Mirasol.
Coeur’s exploration program included:
- 356 line-km of detailed ground magnetics,
- 24 line-km of gradient array geophysics,
- 3,400 m of infill trenching and mapping, and
- 32 shallow diamond holes (average depth 135 m) in 2 campaigns for 4,333 m along the 4.5 km, NW trending epithermal Au-Ag mineralized Sascha Vein Zone and two shallow holes at Sasha Sur.
[1] Silver equivalent (“AgEq”) is calculated using metal prices of US$ 1800/oz for Au and US$ 24/oz for Ag. Recoveries are assumed to be 100% as no metallurgical test data is available.
The equation used is: AgEq g/t = Ag g/t + (Au g/t x 75)
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