Mirasol expands the large Curahue gold-silver vein system, Santa Cruz, Argentina, with new Trenching Assays and Geophysical results

VANCOUVER, July 27, 2015 /CNW/ - Mirasol Resources Ltd. (TSX-V: MRZ, Frankfurt: M8R)  Mirasol Resources is pleased to announce exploration results that further expand the Curahue gold – silver vein prospect at the 100% owned Claudia Project, located adjacent to the large AngloGold Ashanti Cerro Vanguardia gold mine.

• Recent exploration at the Curahue prospect has defined a large-scale, epithermal gold -silver vein system, developed over a 15 km strike length with 6 vein trends outlined to date.
• Trenching through gravel covered resistivity anomalies at the "Io" Trend has exposed intermittent, broad zones of veining over a 2 km strike length, with individual channel sample assays ranging up to 5.9 g/t Au and 120 g/t Ag.    
• At the new "Sinope" Trend, a 61 line-km gradient array geophysical survey has outlined 3.5 km strike-length of resistivity anomalies in gravel covered areas, suggesting the presence of additional, potentially mineralized, large veins.
• At the new "Themisto" Trend, rock chip sampling has returned assay results of up to 0.49 g/t Au and 282 g/t Ag from chalcedonic veinlets associated with a 3.5 km long gradient array resistivity anomaly, also suggesting the presence of gravel covered veins at this trend.     

The Curahue prospect represents a large-scale undrilled epithermal gold – silver prospect located approximately 10 km south of the Cerro Vanguardia mine pits.  The Curahue vein system remained unrecognized until 2011 largely due to an aerially extensive, thin (estimated 1 to 6 m thickness) post-mineral gravel cover that conceals the majority of the prospect. 

Mirasol has previously announced the discovery of the Curahue vein system and initial exploration results (see news release April 18, 2012).  Additional exploration completed in late 2013, and a new understanding of the scale of the vein system from recent desktop analysis and ground checking of these results, has confirmed the presence of an epithermal Au+Ag vein system intermittently developed over a 15 km long northwest oriented corridor.  Despite some historic drilling in and around Curahue by a previous joint venture partner, the large-scale vein system defined by Mirasol remains untested.   

Previously reported Mirasol exploration at Curahue has identified the multi-kilometre long vein trends at Io, Europa, Ganymede and Callisto (Figure 1) that were defined using a combination of gradient array geophysics resistivity anomalies, surface rock chip sampling and geological mapping.  The resistivity trends at Io and Europa were tested by trenching through the gravel which revealed large Au+Ag bearing vein systems hosted in the underlying volcanics, validating the gradient array geophysics as an effective exploration tool to prospect for shallowly buried quartz veins at Curahue.  More recent Mirasol exploration includes additional trenching of the Io Trend, and further geophysics and surface geology that has outlined two new multi-kilometre long anomalies at the Sinope and Themisto Trends.  

To date 28 trenches have been excavated at Io (Figure 2); 21 of these have penetrated the 4 to 5 m thick gravel cover to reveal the underlying epithermal Au+Ag bearing vein zone.  In many cases the trenching successfully revealed sub-outcropping veining hosted by altered volcanic wall rock which Mirasol systematically saw-cut channel sampled.  However in number of cases, vein blocks encountered during trenching were too large to be lifted free of the trench by the excavator to expose the underlying bedrock.  In these situations where Mirasol geologists were confident that these vein blocks approximated in situ outcrop, the vein blocks were mapped as "subcrop" and also channel sampled.

Trench sampling at the Io Trend (Figure 2) is presented as channel samples intervals (Table 1), with corresponding assays giving an indication of the potential Au+Ag grade and width of the vein zones.   The Io Trend contains individual veins up to 2.9 m wide, in vein and veinlet zones that may locally exceed 25 to 30 m width.  Channel sample results range up to 5.86 g/t Au and 120 g/t Ag and demonstrate the presence of a large-scale epithermal Au+Ag vein zone over a 2 km strike length.

A 61 line-km (100 m line spacing, 50 m dipole) gradient array geophysics grid was surveyed over an area directly to the south of the Io Trend extending the previously reported large Curahue gradient array grid.  This new survey has outlined two large gravel covered resistive anomalies totaling 3.5 km in length, defining the new Sinope Trend.  Late gravels conceal all outcrop in the area.  Trenching and/or shallow "scout" drill testing will be required to determine the source of these resistivity anomalies; however given the similarity to the adjacent Io Trend resistive anomalies, confidence is high that these represent additional large vein trends.

At the new Themisto Trend (Figure 3) on the south east end of the Curahue vein system,  reconnaissance rock chip sampling has returned anomalous assays of up to 0.49 g/t Au and 282 g/t Ag from chalcedonic iron-oxide stained fracture zones and high level breccia structures.  Mapping of this zone shows the host rock to be the upper portions of the Chon Aike rhyolite and the overlying Matilda tuff, with local carbonaceous shale intercalations suggesting a syn-mineral hot spring, lacustrine environment at the time of deposition, a geological setting typical of the top of preserved, mineralized epithermal systems.  The geological setting and the chalcedonic nature of the silica associated with the Au+Ag anomalous rock chip samples suggests the potential for improved Au+Ag grades at depth. 

Reconnaissance level 500 m spaced gradient array lines were surveyed over the Themisto Trend and outlined a 3 km long open-ended resistivity anomaly.  The Themisto Trend gradient array lines require an in-fill survey to better define the nature of these geophysical anomalies; however exploration to date suggests the presence of a large, covered, Au+Ag vein zone.                

Mirasol Resources is very pleased with the exploration to date at the Curahue prospect where 5 separate large scale trends have now been outlined by a combination of geophysical, rock chip and trench channel gold-silver anomalies over a 15 km long corridor.  The Curhaue gold-silver prospect represents a large scale, until recently unrecognized exploration target that significantly upgrades the prospectivity of the Claudia project.   Mirasol is actively seeking a Joint Venture partner to advance this and other prospects at Claudia.          

Stephen Nano, President and CEO of Mirasol Resources has approved the technical content of this news release and is a Qualified Person under NI 43 -101. 

Quality Assurance/Quality Control of the Claudia exploration program:

Exploration at the Project was supervised by Stephen C. Nano, President and CEO, who is the Qualified Person under NI 43-101 and Timothy Heenan, Exploration Manager. All technical information for the project was obtained and reported under a formal quality assurance and quality control (QA/QC) program. Drill core, rock channel and rock chip samples were collected under the supervision of Company geologists in accordance with standard industry practice. Samples were dispatched via commercial transport to an ISO 9001:2000-accredited laboratory in Argentina for analysis.

Assay results from drill core samples may be higher, lower or similar to results obtained from surface samples due to surficial oxidation and enrichment processes or due to natural geological grade variations in the primary mineralization.

Forward Looking Statements: The above contains forward looking statements that are subject to a number of known and unknown risks, uncertainties and other factors that may cause actual results to differ materially from those anticipated in our forward looking statements. Factors that could cause such differences include: changes in world commodity markets, equity markets, costs and supply of materials relevant to the mining industry, change in government and changes to regulations affecting the mining industry. Forward-looking statements in this release include statements regarding future exploration programs, operation plans, geological interpretations, mineral tenure issues and mineral recovery processes. Although we believe the expectations reflected in our forward looking statements are reasonable, results may vary, and we cannot guarantee future results, levels of activity, performance or achievements

Neither the TSX Venture Exchange nor its Regulation Services Provider (as that term is defined in the policies of the TSX Venture Exchange) accepts responsibility for the adequacy or accuracy of this release.

SOURCE Mirasol Resources Ltd.